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1.
Behav Brain Sci ; 47: e141, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38934437

RESUMEN

Questions can be raised about the central status that evolutionarily ancient core knowledge systems are given in Spelke's otherwise very compelling theory. So, the existence of domain-general learning capacities has to be admitted, too, and no clear reason is provided to doubt the existence of uniquely human cognitive adaptations. All of these factors should be acknowledged when explaining human thought.


Asunto(s)
Cognición , Conocimiento , Aprendizaje , Humanos , Cognición/fisiología , Aprendizaje/fisiología , Evolución Biológica
2.
Inorg Chem ; 63(8): 3962-3973, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38350090

RESUMEN

The new oxometalates Cs3NbO4 and Cs3TaO4 together with Cs3VO4 crystallize with the K3NO4 structure type [Pnma, a = 12.495(2) Å, b = 9.0183(14) Å, and c = 6.6529(10) Å for the V compound; a = 12.928(2) Å, b = 9.177(3) Å, and c = 6.739(4) Å for the Nb; and a = 12.963(4) Å, b = 9.122(2) Å, and c = 6.774(1) Å for the Ta compound]. Their crystal structures were evaluated on the basis of single-crystal and powder X-ray diffractometry, assisted by vibrational spectroscopy, thermoanalysis, and DFT calculations. The crystal structures contain tetrahedral [M5+O4]3- anions, representing the first occurrence of Nb and Ta in a tetrahedral oxidic environment. Many representatives of the orthorhombic K3NO4 structure type have been described in the literature with a cubic structure model with disordered O atomic positions. Based on studies on Cs3MO4 (M = P, V, Nb, or Ta), we show here three different effects which can lead to (pseudo)cubic data sets. Two of them are problems of crystallographic nature (overlooked twinning or adverse atomic form factor ratios), but the third one, phase transformation into a plastic crystalline high-temperature modification, leads to a "truly" cubic structure with dynamically disordered (freely rotating) oxometalate anions. This might be of interest with respect to a large and growing number of sulfido- and selenidometalate materials which are today in discussion as solid-state electrolytes and to the mechanism of the unusually efficient ion transport therein.

3.
Nat Commun ; 14(1): 5057, 2023 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-37598179

RESUMEN

Atomically thin layered van der Waals heterostructures feature exotic and emergent optoelectronic properties. With growing interest in these novel quantum materials, the microscopic understanding of fundamental interfacial coupling mechanisms is of capital importance. Here, using multidimensional photoemission spectroscopy, we provide a layer- and momentum-resolved view on ultrafast interlayer electron and energy transfer in a monolayer-WSe2/graphene heterostructure. Depending on the nature of the optically prepared state, we find the different dominating transfer mechanisms: while electron injection from graphene to WSe2 is observed after photoexcitation of quasi-free hot carriers in the graphene layer, we establish an interfacial Meitner-Auger energy transfer process following the excitation of excitons in WSe2. By analysing the time-energy-momentum distributions of excited-state carriers with a rate-equation model, we distinguish these two types of interfacial dynamics and identify the ultrafast conversion of excitons in WSe2 to valence band transitions in graphene. Microscopic calculations find interfacial dipole-monopole coupling underlying the Meitner-Auger energy transfer to dominate over conventional Förster- and Dexter-type interactions, in agreement with the experimental observations. The energy transfer mechanism revealed here might enable new hot-carrier-based device concepts with van der Waals heterostructures.

4.
Biol Philos ; 37(2): 8, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35261418

RESUMEN

Humans are standouts in their propensity to trade. More specially, the kind of trading found in humans-featuring the exchange of many different goods and services with many different others, for the mutual benefit of all the involved parties-far exceeds anything that is found in any other creature. However, a number of important questions about this propensity remain open. First, it is not clear exactly what makes this propensity so different in the human case from that of other animals. Second, it is not clear why other animals did not acquire this propensity to the extent that humans did. Third, it is not clear what explains the fact that the extent to which humans engage in trade is culturally highly variable. The paper argues that at the heart of the human-animal divergence in this propensity is the particular socio-cultural environment in which humans evolved. This has led them to sometimes, but not always, acquire the cognitive technology (writing, algebra, tallying devices, money, etc.) to support a sophisticated disposition and capacity for reciprocal cooperation, and deep and wide concepts of property and exchange value.

5.
Behav Brain Sci ; 43: e23, 2020 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-32159475

RESUMEN

Resource-rational analysis would profit from being integrated more explicitly with an evolutionary psychological perspective. In particular, by taking more strongly into consideration the fact that efficiency considerations are a key driver of the evolution of human and animal minds, it becomes clearer: (1) why it is reasonable to assume that cognitive mechanisms trade-off accuracy against effort, (2) how this trade-off occurs, and (3) how to overcome some of the challenges of resource-rational analysis.


Asunto(s)
Evolución Biológica , Cognición , Animales , Humanos
6.
Nano Lett ; 18(5): 3203-3208, 2018 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-29635914

RESUMEN

The small gap semiconductor α-RuCl3 has emerged as a promising candidate for quantum spin liquid materials. Thus far, Raman spectroscopy, neutron scattering, and magnetization measurements have provided valuable hints for collective spin behavior in α-RuCl3 bulk crystals. However, the goal of implementing α-RuCl3 into spintronic devices would strongly benefit from the possibility of electrically probing these phenomena. To address this, we first investigated nanoflakes of α-RuCl3 by Raman spectroscopy and observed similar behavior as in the case of the bulk material, including the signatures of possible fractionalized excitations. In complementary experiments, we investigated the electrical charge transport properties of individual α-RuCl3 nanoflakes in the temperature range between 120 and 290 K. The observed temperature-dependent electrical resistivity is consistent with variable range hopping behavior and exhibits a transition at about 180 K, close to the onset temperature observed in our Raman measurements. In conjunction with the established relation between structure and magnetism in the bulk, we interpret this transition to coincide with the emergence of fractionalized excitations due to the Kitaev interactions in the nanoflakes. Compared to the bulk samples, the transition temperature of the underlying structural change is larger in the nanoflakes. This difference is tentatively attributed to the dimensionality of the nanoflakes as well as the formation of stacking faults during mechanical exfoliation. The demonstrated devices open up novel perspectives toward manipulating the Kitaev-phase in α-RuCl3 via electrical means.

7.
Behav Brain Sci ; 41: e112, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-31064490

RESUMEN

It is not clear how a moral demand alone can motivate an agent to exclude those who fail to act as the demand states. A more plausible hypothesis for the evolution of human moral cognition is based on seeing moral demands as subjective, but inherently conjunctive. This subjectivist-conjunctive proposal can still account for the apparent externalization of moral demands.


Asunto(s)
Helados , Nacionalsocialismo , Cognición , Humanos , Relaciones Interpersonales , Principios Morales
8.
Inorg Chem ; 56(11): 6318-6329, 2017 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-28481108

RESUMEN

We prepared trirutile-type polycrystalline samples of CuTa2O6 by low-temperature decomposition of a Cu-Ta-oxalate precursor. Diffraction studies at room temperature identified a slight monoclinic distortion of the hitherto surmised tetragonal trirutile crystal structure. Detailed high-temperature X-ray and neutron powder diffraction investigations as well as Raman scattering spectroscopy revealed a structural phase transition at 503(3) K from the monoclinic structure to the tetragonal trirutile structure. GGA+U density functional calculations of the spin-exchange parameters as well as magnetic susceptibility and isothermal magnetization measurements reveal that CuTa2O6 is a new 1D Heisenberg magnet with predominant anti-ferromagnetic nearest-neighbor intrachain spin-exchange interaction of ∼50 K. Interchain exchange is a factor of ∼5 smaller. Heat capacity and low-temperature high-intensity neutron powder diffraction studies could not detect long-range order down to 0.45 K.

9.
Stud Hist Philos Biol Biomed Sci ; 56: 15-23, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26778352

RESUMEN

I argue for differences in the cognitive efficiency of different psychologies underlying helping behavior, and present an account of the adaptive pressures that result from these differences. Specifically, I argue that organisms often face pressure to move away from only being egoistically motivated to help: non-egoistic organisms are often able to determine how to help other organisms more quickly and with less recourse to costly cognitive resources like concentration and attention. Furthermore, I also argue that, while these pressures away from pure egoism can lead to the evolution of altruists, they can also lead to the evolution of reciprocation-focused behaviorist helpers or even of reflex-driven helpers (who are neither altruists nor egoists). In this way, I seek to broaden the set of considerations typically taken into account when assessing the evolution of the psychology of helping behavior-which tend to be restricted to matters of reliability-and also try to make clearer the role of evolutionary biological considerations in the discussion of this apparently straightforwardly psychological phenomenon.


Asunto(s)
Altruismo , Evolución Biológica , Cognición , Ego , Conducta de Ayuda , Ética , Humanos
11.
Stud Hist Philos Biol Biomed Sci ; 44(4 Pt A): 595-603, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24125685

RESUMEN

A key component of much current research in behavioral ecology, cognitive science, and economics is a model of the mind at least partly based on beliefs and desires. However, despite this prevalence, there are still many open questions concerning both the structure and the applicability of this model. This is especially so when it comes to its 'desire' part: in particular, it is not yet entirely clear when and why we should expect organisms to be desire-based-understood so as to imply that they consult explicit tokenings of what they ought to do-as opposed to being drive-based-understood so as to imply that they react to the world using behavioral reflexes. In this paper, I present the beginnings of an answer to this question. To do this, I start by showing that an influential recent attempt to address these issues-due to Kim Sterelny-fails to be fully successful, as it does not make sufficiently clear what the relative benefits and disadvantages of drive-based and desire-based cognitive architectures are. I then present an alternative account of this matter based on the idea that organisms that can follow explicit behavioral rules (i.e. which have desires) avoid having to memorize a large set of state of the world-action connections-which can (though need not) be adaptive. Finally, I apply this account to the question of what the cognitive value of mental representations should be seen to be; here, I conclude that-contrary to some recent claims-relying on mental representations can make decision making easier, not harder, but also that-in line with these recent claims-whether it does so depends on the details of the case.


Asunto(s)
Evolución Biológica , Toma de Decisiones , Motivación , Humanos
12.
Hist Philos Life Sci ; 35(2): 193-212, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24466632

RESUMEN

One of the most well known methodological criticisms of evolutionary psychology is Gould's claim that the program pays too much attention to adaptations, and not enough to exaptations. Almost as well known is the standard rebuttal of that criticism: namely, that the study of exaptations in fact depends on the study of adaptations. However, as I try to show in this paper, it is premature to think that this is where this debate ends. First, the notion of exaptation that is commonly used in this debate is different from the one that Gould and Vrba originally defined. Noting this is particularly important, since, second, the standard reply to Gould's criticism only works if the criticism is framed in terms of the former notion of exaptation, and not the latter. However, third, this ultimately does not change the outcome of the debate much, as evolutionary psychologists can respond to the revamped criticism of their program by claiming that the original notion of exaptation is theoretically and empirically uninteresting. By discussing these issues further, I also seek to determine, more generally, which ways of approaching the adaptationism debate in evolutionary biology are useful, and which not.


Asunto(s)
Evolución Biológica , Biología/historia , Psicología/historia , Adaptación Biológica , Adaptación Psicológica , Historia del Siglo XX , Historia del Siglo XXI , Humanos
13.
Stud Hist Philos Biol Biomed Sci ; 41(1): 41-9, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20185083

RESUMEN

David Buss's Sexual Strategies Theory is one of the major evolutionary psychological research programmes, but, as I try to show in this paper, its theoretical and empirical foundations cannot yet be seen to be fully compelling. This lack of cogency comes about due to Buss's failure to attend to the interactive nature of his subject matter, which leads him to overlook two classic and well known issues of game theoretic and evolutionary biological analysis. Firstly, Buss pays insufficient attention to the fact that, since mate choice is a cooperative decision, what is adaptive for the two sexes individually is irrelevant to the evolutionary explanation of our sexual strategies; instead, all that matters is what is adaptive given the choices made by the other sex. Secondly, Buss does not pay enough attention to the difference between polymorphic and monomorphic evolutionarily stable states in his attempt to empirically confirm his theory. Because of this, the data he presents and analyses are unable to show that natural selection is the most important element in the explanation of the origins of our sexual strategies. In this way, I try to make clear that, at least as things stand now, Buss has failed to provide compelling grounds for thinking that Sexual Strategies Theory can make a major contribution to human psychology.


Asunto(s)
Evolución Biológica , Toma de Decisiones , Teoría del Juego , Psicología/historia , Conducta Sexual/historia , Sociobiología/historia , Conducta de Elección , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Masculino , Selección Genética , Sexualidad/historia , Conducta Social
14.
Phys Chem Chem Phys ; 11(27): 5628-33, 2009 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-19842480

RESUMEN

Lithium-doped polymer-derived silicon carbonitride ceramics (SiCN:Li) synthesized at various pyrolysis temperatures, have been investigated by means of multifrequency and multipulse electron paramagnetic resonance (EPR) and Raman spectroscopy in order to determine different defect states that may impact the materials electronic properties. In particular, carbon- and silicon-based 'dangling bonds' at elevated, as well as metallic networks containing Li0 in the order of 1 microm at low pyrolysis temperatures have been observed in concentrations ranging between 10(14) and 10(17) spins mg(-1).

16.
Am J Hematol ; 71(2): 105-8, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12353309

RESUMEN

The only established treatment for patients with thrombotic thrombocytopenic purpura (TTP) is plasma exchange against fresh frozen plasma. For cases refractory to plasma exchange, no generally treatment schedule exists. One option is immunosuppressive therapy with corticosteroids and vincristine. Rituximab is a chimeric monoclonal antibody directed against the CD20 antigen, and it has been successfully used in B-cell malignancies and is being investigated in autoimmune diseases. Its efficacy in TTP has not yet been determined. We report two female patients with severe TTP refractory to multiple courses of plasmapheresis, high-dose steroid treatment, and vincristine who responded after adding rituximab while continuing plasmapheresis.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Púrpura Trombocitopénica Trombótica/tratamiento farmacológico , Adulto , Anticuerpos Monoclonales de Origen Murino , Bilirrubina/sangre , Supervivencia sin Enfermedad , Femenino , Humanos , Inducción de Remisión , Rituximab , Terapia Recuperativa , Resultado del Tratamiento
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