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Cooperative Interactions (cooperative + interaction)
Selected AbstractsChemInform Abstract: Engineering Polymer-Enhanced Bimetallic Cooperative Interactions in the Hydrolytic Kinetic Resolution of Epoxides.CHEMINFORM, Issue 21 2008Xiaolai Zheng Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Self-Association of Bis-Dendritic Organogelators: The Effect of Dendritic Architecture on Multivalent Cooperative InteractionsCHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2010Myungeun Seo Dr. Abstract A series of bis-dendritic gelators consisting of a benzamide dendron and an alkyl dendron were synthesized to investigate the dendritic effect on self-assembly. The gelators with a first-generation benzamide (benzamide- G1) dendron or a first-generation alkyl (alkyl- G1) dendron formed stable gels in most aromatic solvents, and their self-assembled fibrillar networks were imaged by electron microscopy. The unbranched molecule (G0 - G0) or the molecule possessing a second-generation benzamide (benzamide- G2) dendron did not form gels. Differential scanning calorimetry, powder X-ray diffraction, and Fourier transform IR studies revealed that introduction of a dendritic branch strongly affected the molecular packing as well as the strength of intermolecular interactions. Furthermore, concentration-dependent diffusion coefficient measurements and the evaluation of association constants by 1H NMR spectroscopy indicated that bis-dendritic gelators with a benzamide- G1 dendron possessed high association constants and formed large aggregates, whereas molecules with a single benzamide formed dimers in chloroform. The formation of self-assembled fibrillar networks was driven by the multivalent and cooperative hydrogen bonding observed in the benzamide- G1 dendrons. ,,, stacking of aromatic groups and van der Waals interactions between alkyl chains also played roles in the self-assembly process, thus indicating that a spatial balance between two dendrons is important. [source] Cooperative interaction of n -butylammonium ion with 1,3-alternate tetrapropoxycalix [4]arene: NMR and theoretical studyMAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2008Jaroslav K Abstract The interaction of 1,3-alternate tetrapropoxycalix[4]arene (1) with n -butylammonium ion (2) in CD2Cl2 was examined using 1H, 13C and 14N NMR spectroscopy and DFT (density functional theory) calculations. NMR shows that 1 forms with 2 an equimolecular hydrogen-bonded complex with the equilibrium constant 5.91 × 103 l/mol at 296 K. The structure of the complex can be shown to be asymmetric at 203 K, with 2 interacting by hydrogen bonds with the two ethereal oxygen atoms of one half of 1 and with the , system of the other half, but is rapidly averaged to an apparent C4h symmetry by chemical exchange at higher temperatures. Using two related but independent techniques based on transverse and rotating-frame proton relaxation, it is shown that only an intermolecular exchange of 2 between the bound and free states takes place, in contrast to previously studied interaction of 1 with H3O+. Its correlation time is 0.169 ms. It is shown by DFT calculations that such swift exchange is not possible without a cooperative interaction of both 2 and 1 with several molecules of water present. Similarities and contrasts between the exchange processes of 2 and H3O+ bound to 1 are discussed, in particular with respect to the apparent quantum tunneling of the latter inside the molecule of the complex. Copyright © 2008 John Wiley & Sons, Ltd. [source] Cooperative interactions among p53, bcl-2 and Epstein,Barr virus latent membrane protein 1 in nasopharyngeal carcinoma cellsPATHOLOGY INTERNATIONAL, Issue 7 2004Lai-Fa Sheu Interactions among p53, bcl-2 and Epstein,Barr virus (EBV) latent membrane protein 1 (LMP1) in nasopharyngeal carcinoma (NPC) cells were evaluated by gene cotransfections. The data showed that bcl-2 expression was not only able to prevent the growth suppression induced by wild-type p53 but was also paradoxically able to inhibit the growth enhancement induced by mutant p53. Latent membrane protein 1 was shown to be capable of overcoming the growth inhibition induced by wild-type p53 and the synergistic cooperation with bcl-2 to enhance cellular growth. Latent membrane protein 1 could also cooperate with mutant p53 to provide a growth advantage for NPC cells. Most NPC revealed detectable overexpression of p53, and the majority of those were a wild type possibly responding to EBV infection. The coexpression of bcl-2 and LMP1 was thought to inhibit the growth suppression induced by wild-type p53 in NPC. But there was no associated expression between LMP1 and bcl-2 because we demonstrated that transfected LMP1 failed to induce bcl-2 expression in NPC cells in contrast to the findings in B cells. It is theorized that the cooperative expression of bcl-2 and LMP1 exists in the majority of NPC, while a minority of NPC have cooperative expression of LMP1 and mutant p53. Each cooperative interaction could play an important role in the development and progression of NPC. [source] Exploring lymphocyte differentiation pathwaysIMMUNOLOGICAL REVIEWS, Issue 1 2002Max D. Cooper Summary: Highlights in a 4-decade exploration of lymphocyte differentiation begin with comparative studies in birds and mammals leading to recognition of the separate T- and B-cell differentiation pathways and their cooperative interaction. The global effects of aborting IgM B-cell development with anti-µ antibodies indicated that B cells can undergo immunoglobulin isotype switching. A search for the mammalian bursa equivalent that began with an extended excursion through the gut-associated lymphoepithelial tissues ultimately led to the hematopoietic tissue origin of mammalian B cells. The identification of the precursors of B cells in hematopoietic tissues provided an expanded view of the life history of B cells. A recurring theme in this essay is the interplay between understanding normal lymphocyte differentiation and the defects that underlie immunodeficiency diseases and lymphoid malignancies. [source] Cooperative interaction of n -butylammonium ion with 1,3-alternate tetrapropoxycalix [4]arene: NMR and theoretical studyMAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2008Jaroslav K Abstract The interaction of 1,3-alternate tetrapropoxycalix[4]arene (1) with n -butylammonium ion (2) in CD2Cl2 was examined using 1H, 13C and 14N NMR spectroscopy and DFT (density functional theory) calculations. NMR shows that 1 forms with 2 an equimolecular hydrogen-bonded complex with the equilibrium constant 5.91 × 103 l/mol at 296 K. The structure of the complex can be shown to be asymmetric at 203 K, with 2 interacting by hydrogen bonds with the two ethereal oxygen atoms of one half of 1 and with the , system of the other half, but is rapidly averaged to an apparent C4h symmetry by chemical exchange at higher temperatures. Using two related but independent techniques based on transverse and rotating-frame proton relaxation, it is shown that only an intermolecular exchange of 2 between the bound and free states takes place, in contrast to previously studied interaction of 1 with H3O+. Its correlation time is 0.169 ms. It is shown by DFT calculations that such swift exchange is not possible without a cooperative interaction of both 2 and 1 with several molecules of water present. Similarities and contrasts between the exchange processes of 2 and H3O+ bound to 1 are discussed, in particular with respect to the apparent quantum tunneling of the latter inside the molecule of the complex. Copyright © 2008 John Wiley & Sons, Ltd. [source] Cooperative interactions among p53, bcl-2 and Epstein,Barr virus latent membrane protein 1 in nasopharyngeal carcinoma cellsPATHOLOGY INTERNATIONAL, Issue 7 2004Lai-Fa Sheu Interactions among p53, bcl-2 and Epstein,Barr virus (EBV) latent membrane protein 1 (LMP1) in nasopharyngeal carcinoma (NPC) cells were evaluated by gene cotransfections. The data showed that bcl-2 expression was not only able to prevent the growth suppression induced by wild-type p53 but was also paradoxically able to inhibit the growth enhancement induced by mutant p53. Latent membrane protein 1 was shown to be capable of overcoming the growth inhibition induced by wild-type p53 and the synergistic cooperation with bcl-2 to enhance cellular growth. Latent membrane protein 1 could also cooperate with mutant p53 to provide a growth advantage for NPC cells. Most NPC revealed detectable overexpression of p53, and the majority of those were a wild type possibly responding to EBV infection. The coexpression of bcl-2 and LMP1 was thought to inhibit the growth suppression induced by wild-type p53 in NPC. But there was no associated expression between LMP1 and bcl-2 because we demonstrated that transfected LMP1 failed to induce bcl-2 expression in NPC cells in contrast to the findings in B cells. It is theorized that the cooperative expression of bcl-2 and LMP1 exists in the majority of NPC, while a minority of NPC have cooperative expression of LMP1 and mutant p53. Each cooperative interaction could play an important role in the development and progression of NPC. [source] Gain-narrowed emissions of thiophene/phenylene co-oligomer single crystalsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2009Toru Hiramatsu Abstract In order to elucidate the origin of gain-narrowed photoluminescence spectra of 5,5,-bis(4-biphenylyl)-2,2,:5,,2,-terthiophene (BP3T) single crystals, the dependence of excitation energy threshold on excitation lengths was studied at 12 K. The emission peak of the 0-1 vibrational band was narrowed at a constant excitation density irrespective of the excitation length, indicating that the gain-narrowing followed a stimulated emission process. On the other hand, the excitation density threshold for the 0-2 peak decreased with increasing excitation length. The latter behaviour is suggestive of a cooperative interaction among uniaxially oriented transition dipoles in the BP3T crystal. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Short- and long-term differential effects of neuroprotective drug NS-7 on voltage-dependent sodium channels in adrenal chromaffin cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2000Hiroki Yokoo In cultured bovine adrenal chromaffin cells, NS-7 [4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride], a newly-synthesized neuroprotective drug, inhibited veratridine-induced 22Na+ influx via voltage-dependent Na+ channels (IC50=11.4 ,M). The inhibition by NS-7 occurred in the presence of ouabain, an inhibitor of Na+,K+ ATPase, but disappeared at higher concentration of veratridine, and upon the washout of NS-7. NS-7 attenuated veratridine-induced 45Ca2+ influx via voltage-dependent Ca2+ channels (IC50=20.0 ,M) and catecholamine secretion (IC50=25.8 ,M). Chronic (12 h) treatment of cells with NS-7 increased cell surface [3H]-STX binding by 86% (EC50=10.5 ,M; t1/2=27 h), but did not alter the KD value; it was prevented by cycloheximide, an inhibitor of protein synthesis, or brefeldin A, an inhibitor of vesicular transport from the trans -Golgi network, but was not associated with increased levels of Na+ channel ,- and ,1 -subunit mRNAs. In cells subjected to chronic NS-7 treatment, 22Na+ influx caused by veratridine (site 2 toxin), ,-scorpion venom (site 3 toxin) or ,-scorpion venom (site 4 toxin) was suppressed even after the extensive washout of NS-7, and veratridine-induced 22Na+ influx remained depressed even at higher concentration of veratridine; however, either ,- or ,-scorpion venom, or Ptychodiscus brevis toxin-3 (site 5 toxin) enhanced veratridine-induced 22Na+ influx as in nontreated cells. These results suggest that in the acute treatment, NS-7 binds to the site 2 and reversibly inhibits Na+ channels, thereby reducing Ca2+ channel gating and catecholamine secretion. Chronic treatment with NS-7 up-regulates cell surface Na+ channels via translational and externalization events, but persistently inhibits Na+ channel gating without impairing the cooperative interaction between the functional domains of Na+ channels. British Journal of Pharmacology (2000) 131, 779,787; doi:10.1038/sj.bjp.0703622 [source] ELECTROPHYSIOLOGICAL EVIDENCE FOR THE INTERACTION OF SUBSTANCE P AND GLUTAMATE ON A, AND C AFFERENT FIBRE ACTIVITY IN RAT HAIRY SKINCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2006Qi Zhang SUMMARY 1The purpose of the present study was to investigate whether there was a cooperative interaction between substance P (SP) and glutamate (GLU) administered subcutaneously on A, and C primary afferent fibre activity in dorsal hairy skin of the rat in vivo. The single unit activities of A, and C afferent fibres were recorded by isolation of fibre filaments from the dorsal cutaneous nerve branches and the effects of subcutaneous injections of low doses of SP, GLU and SP + GLU on activity were determined. 2Sub-threshold doses of SP (1 µmol/L, 10 µL) administered subcutaneously into the dorsal hairy skin had no effect on the afferent discharges of either A, or C units. 3The afferent discharges of 35% (11/31) of A, fibres and 33% (6/18) of C fibres were increased by local injection of the submaximal doses of GLU (10 µmol/L, 10 µL) into the receptive fields. 4The GLU-induced excitatory response was significantly enhanced by coinjection of subthreshold doses of SP. The mean discharge rates of A, fibres and C fibres were increased from 5.84 ± 1.54 and 5.02 ± 2.65 impulses/min to 19.91 ± 4.35 and 17.58 ± 5.59 impulses/min, respectively, whereas the excitatory proportions of A, and C fibres were increased from 35 and 33% to 84 and 83%, respectively. The duration of the excitation for A, fibres and C fibres was also significantly increased after coinjection of SP + GLU compared with that observed when either substance was given alone. 5The present study provides electrophysiological evidence for an interaction between receptors for SP and GLU on the fine fibres activities in rat hairy skin, which may be involved in the mechanisms of hyperalgesia. [source] THE ADAPTIVE DYNAMICS OF ALTRUISM IN SPATIALLY HETEROGENEOUS POPULATIONSEVOLUTION, Issue 1 2003JEAN-FRANĒOIS LE GALLIARD Abstract., We study the spatial adaptive dynamics of a continuous trait that measures individual investment in altruism. Our study is based on an ecological model of a spatially heterogeneous population from which we derive an appropriate measure of fitness. The analysis of this fitness measure uncovers three different selective processes controlling the evolution of altruism: the direct physiological cost, the indirect genetic benefits of cooperative interactions, and the indirect genetic costs of competition for space. In our model, habitat structure and a continuous life cycle makes the cost of competing for space with relatives negligible. Our study yields a classification of adaptive patterns of altruism according to the shape of the costs of altruism (with decelerating, linear, or accelerating dependence on the investment in altruism). The invasion of altruism occurs readily in species with accelerating costs, but large mutations are critical for altruism to evolve in selfish species with decelerating costs. Strict selfishness is maintained by natural selection only under very restricted conditions. In species with rapidly accelerating costs, adaptation leads to an evolutionarily stable rate of investment in altruism that decreases smoothly with the level of mobility. A rather different adaptive pattern emerges in species with slowly accelerating costs: high altruism evolves at low mobility, whereas a quasi-selfish state is promoted in more mobile species. The high adaptive level of altruism can be predicted solely from habitat connectedness and physiological parameters that characterize the pattern of cost. We also show that environmental changes that cause increased mobility in those highly altruistic species can beget selection-driven self-extinction, which may contribute to the rarity of social species. [source] 1D and 3D Ionic Liquid,Aluminum Hydroxide Hybrids Prepared via an Ionothermal Process,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2007S. Park Abstract Room-temperature ionic liquids (RTILs) are used as hierarchically multifunctional components by employing them not only as templates and co-solvents for fabricating nanostructured materials but also proton conductors for electrochemical devices. RTIL/aluminum hydroxide (RTIL,Al) hybrids containing various nanometer-sized shapes, including 1D nanorods with hexagonal tips, straight and curved nanofibers, nanofibers embedded in a porous network, and 3D octahedral-, polyhedral-, and angular spherical shapes are synthesized via a one-pot ionothermal process. The structures or shapes of the RTIL,Al hybrids are related to the anionic moieties, alkyl chain length of the RTILs, and the humidity during fabrication. In particular, the introduction of water molecules into the interface led to 3D isotropic growth of the hybrids by influencing intermolecular interactions between the RTILs and the building blocks. The shapes of the nanohybrids fabricated from RTILs containing short alkyl chains were dependent on the types of anions and on the level of humidity. These results indicate that the cooperative interactions between RTILs and aluminum hydroxides induces emerging shape-controlled hybrids. The shape-controlled nanohybrids show enhanced electrochemical properties compared to those of a conventional hybrid prepared by mixing RTILs and aluminum hydroxides, exhibiting tenfold or higher proton conductivity under anhydrous condition and thermal stability as a result of the continuous proton conduction channel and the one-pot-assembled nanoconfinement. This method is expected to be a useful technique for controlling the diverse shapes of nanometer-sized crystalline inorganic materials for a variety of applications, such as fuel cells, solar cells, rechargeable batteries, and biosensors. [source] Tris(4-cyanophenyl)amine: Simple Synthesis via Self-assembly; Strong Fluorescence in Solution, Nano/microcrystals, and Solid,ADVANCED FUNCTIONAL MATERIALS, Issue 13 2007A. Patra Abstract The threefold symmetric molecule, tris(4-cyanophenyl)amine (TCPA) is synthesized from 4-fluorocyanobenzene by treatment with potassium carbonate in dimethylsulfoxide; the occurrence of the reaction without any amine reagent suggests the involvement of a novel self-assembly process. A reprecipitation strategy provides stable colloids containing highly monodisperse nano/microcrystals with well-defined cubic morphology and sizes tunable from 250 to 500,nm. The solution, colloid, and solid states of TCPA exhibit strong blue fluorescence; the colloid shows dual emission with an unusually small Stokes shift. Computational investigations are carried out on the molecule and supramolecular assemblies derived from the crystal structure. Coupled with detailed spectroscopic studies, they show that the emission in the colloidal and solid states can be attributed to energy levels resulting from the intermolecular interactions within different aggregation motifs in the condensed phase and energy cascades between them. The computations also reveal the presence of cooperative interactions in the molecular crystal contributing to its high thermal stability. The strong light emission exhibited by TCPA, concurrently in the solution, nano/microcrystal, and solid states establishes it as a novel molecular material of potential practical utility; it has led to the exploration of the underlying mechanism that describes the phenomena observed in the different physical states. [source] Conserved regions from Plasmodium falciparum MSP11 specifically interact with host cells and have a potential role during merozoite invasion of red blood cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2010Ana Zuleima Obando-Martinez Abstract Despite significant global efforts, a completely effective vaccine against Plasmodium falciparum, the species responsible for the most serious form of malaria, has not been yet obtained. One of the most promising approaches consists in combining chemically synthesized minimal subunits of parasite proteins involved in host cell invasion, which has led to the identification of peptides with high binding activity (named HABPs) to hepatocyte and red blood cell (RBC) surface receptors in a large number of sporozoite and merozoite proteins, respectively. Among these proteins is the merozoite surface protein 11 (MSP11), which shares important structural and immunological features with the antimalarial vaccine candidates MSP1, MSP3, and MSP6. In this study, 20-mer-long synthetic peptides spanning the complete sequence of MSP11 were assessed for their ability to bind specifically to RBCs. Two HABPs with high ability to inhibit invasion of RBCs in vitro were identified (namely HABPs 33595 and 33606). HABP-RBC bindings were characterized by means of saturation assays and Hill analysis, finding cooperative interactions of high affinity for both HABPs (nH of 1.5 and 1.2, Kd of 800 and 600,nM for HABPs 33595 and 33606, respectively). The nature of the possible RBC receptors for MSP11 HABPs was studied in binding assays to enzyme-treated RBCs and cross-linking assays, finding that both HABPs use mainly a sialic acid-dependent receptor. An analysis of the immunological, structural and polymorphic characteristics of MSP11 HABPs supports including these peptides in further studies with the aim of designing a fully effective protection-inducing vaccine against malaria. J. Cell. Biochem. 110: 882,892, 2010. © 2010 Wiley-Liss, Inc. [source] Quantitative analysis of association between herpesviruses and bacterial pathogens in periodontitisJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2008I. Saygun Background and Objective:, The development of human periodontitis may depend upon cooperative interactions among herpesviruses, specific pathogenic bacteria and tissue-destructive inflammatory mediators. This study sought to identify associations among human cytomegalovirus, Epstein,Barr virus and six putative periodontopathic bacteria in periodontitis lesions. Material and Methods:, Fifteen periodontitis patients (nine with aggressive periodontitis and six with chronic periodontitis) and 15 periodontally normal subjects were included in the study. In each study subject, a microbiological sample was collected, using a curette, from the deepest periodontal probing depth of the dentition. A real-time TaqMan® polymerase chain reaction assay was employed to determine the subgingival counts of human cytomegalovirus, Epstein,Barr virus, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Campylobacter rectus. Statistical analysis was performed using the Student's t -test, the Pearson correlation coefficient test and the single variable logistic regression test for odds ratio-based risk calculation. Results:, Human cytomegalovirus was detected in eight periodontitis lesions and in one normal periodontal site, Epstein,Barr virus was detected in nine periodontitis lesions and in two normal periodontal sites, and the study bacteria were detected in 6,15 periodontitis lesions and in 1,11 normal periodontal sites. Correlations were found between counts of human cytomegalovirus and Epstein,Barr virus, between counts of human cytomegalovirus and P. gingivalis, T. forsythia and C. rectus, and between counts of Epstein,Barr virus and P. gingivalis and T. forsythia. Human cytomegalovirus and Epstein,Barr virus counts were also positively associated with the level of periodontal attachment loss, probing pocket depth and gingival bleeding on probing. Conclusion:, This study confirmed that periodontal human cytomegalovirus and Epstein,Barr virus are associated with major periodontopathic bacteria and with the severity of periodontal disease. The finding of abundant herpesviruses in periodontitis lesions redefines the pathogenic paradigm of the disease. Understanding the interplay between herpesviruses and specific bacterial species in the pathogenesis of periodontitis may form the basis for new approaches to preventing, reducing or delaying tissue breakdown from periodontal infections. [source] A new method for the determination of cooperative hydrogen bonding enthalpy of proton acceptors with associated species of alcoholsJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 4 2006Boris N. Solomonov Abstract A calorimetric method for the determination of cooperative hydrogen bonding (HB) enthalpy of protonacceptors (B) with associated species of alcohols is proposed. The average enthalpy of cooperative HB ofpyridine with associated species of alcohols was found to be ,19.8,±,0.6,kJ,mol,1 for all alcohols investigated. Thisvalue exceeds the enthalpy of HB in the complex ROH,,,NC5H5 (the average for all alcohols is ,15.8,± 0.2,kJ,mol,1) by 20,30%. Cooperativity factors (Ab, AOx) of hydrogen bonds for (ROH)2,,,NC5H5 complexes were determined using the IR-spectroscopic method. The average values for the alcohols under consideration were found to be Ab,=,1.41,±,0.04 and AOx,=,1.54,±,0.05. On the basis of IR-spectroscopic and calorimetric data, the enthalpy of cooperative interactions of pyridine with the dimer (ROH)2 was estimated. This value for all the alcohols studied is, on average, ,20.9,±,0.1,kJ,mol,1. Copyright © 2006 John Wiley & Sons, Ltd. [source] Cognitive adaptations for n -person exchange: the evolutionary roots of organizational behaviorMANAGERIAL AND DECISION ECONOMICS, Issue 2-3 2006John Tooby Organizations are composed of stable, predominantly cooperative interactions or n -person exchanges. Humans have been engaging in n -person exchanges for a great enough period of evolutionary time that we appear to have evolved a distinct constellation of species-typical mechanisms specialized to solve the adaptive problems posed by this form of social interaction. These mechanisms appear to have been evolutionarily elaborated out of the cognitive infrastructure that initially evolved for dyadic exchange. Key adaptive problems that these mechanisms are designed to solve include coordination among individuals, and defense against exploitation by free riders. Multi-individual cooperation could not have been maintained over evolutionary time if free riders reliably benefited more than contributors to collective enterprises, and so outcompeted them. As a result, humans evolved mechanisms that implement an aversion to exploitation by free riding, and a strategy of conditional cooperation, supplemented by punitive sentiment towards free riders. Because of the design of these mechanisms, how free riding is treated is a central determinant of the survival and health of cooperative organizations. The mapping of the evolved psychology of n -party exchange cooperation may contribute to the construction of a principled theoretical foundation for the understanding of human behavior in organizations. Copyright © 2006 John Wiley & Sons, Ltd. [source] Cooperation and Communication in the 2nd Year of LifeCHILD DEVELOPMENT PERSPECTIVES, Issue 1 2007Michael Tomasello ABSTRACT,Although primates have evolved complex cognitive skills and strategies for competing with others in their social group, only humans have developed complex cognitive skills and motivations for collaborating with one another in joint endeavors. This cooperative dimension of human cognition emerges most clearly around the first birthday as children begin to collaborate and communicate with joint intentions and joint attention. This collaboration is also grounded in social motivations for helping and sharing with others that are unique to humans. In using the skills of shared intentionality that underlie these cooperative interactions, 1-year-olds come to create perspectival cognitive representations. [source] | ||||||||||||||||