How to do things without words

Clark and Chalmers (1998) defend the hypothesis of an ‘Extended Mind’, maintaining that beliefs and other paradigmatic mental states can be implemented outside the central nervous system or body. Aspects of the problem of ‘language acquisition’ are considered in the light of the extended mind hypothesis. Rather than ‘language’ as typically understood, the object of study is something called ‘utterance-activity’, a term of art intended to refer to the full range of kinetic and prosodic features of the on-line behaviour of interacting humans. It is argued that utterance activity is plausibly regarded as jointly controlled by the embodied activity of interacting people, and that it contributes to the control of their behaviour. By means of specific examples it is suggested that this complex joint control facilitates easier learning of at least some features of language. This in turn suggests a striking form of the extended mind, in which infants’ cognitive powers are augmented by those of the people with whom they interact

The Quasi-1D S=1/2 Antiferromagnet Cs2CuCl4 in a Magnetic Field

Magnetic excitations of the quasi-1D S=1/2 Heisenberg antiferromagnet (HAF) Cs2CuCl4 have been measured as a function of magnetic field using neutron scattering. For T<0.62 K and B=0 T the weak inter-chain coupling produces 3D incommensurate ordering. Fields greater than Bc =1.66 T, but less than the field (~8 T) required to fully align the spins, are observed to decouple the chains, and the system enters a disordered intermediate-field phase (IFP). The IFP excitations are in agreement with the predictions of Muller et al. for the 1D S=1/2 HAF, and Talstra and Haldane for the related 1/r^2 chain (the Haldane-Shastry model). This behaviour is inconsistent with linear spin-wave theory.Comment: 10 pages, 4 encapsulated postscript figures, LaTeX, to be published in PRL, e-mail comments to [email protected]

Orbital and Spin Excitations in Cobalt Oxide

By means of neutron scattering we have determined new branches of magnetic excitations in orbitally active CoO (TN=290 K) up to 15 THz and for temperatures from 6 K to 450 K. Data were taken in the (111) direction in six single-crystal zones. From the dependence on temperature and Q we have identified several branches of magnetic excitation. We describe a model for the coupled orbital and spin states of Co2+ subject to a crystal field and tetragonal distortion.Comment: To be published in Physica B (Proceedings of SCES07 conference in Houston

Group 13 Decamethylmetallocenium Cations

Salts containing the decamethylmetallocenium cations, [( C5Me5) M-2](+) ( or Cp*M-2(+)) of the group 13 "metals" B, Al and Ga have been prepared using a variety of synthetic routes. Precursor molecules of the type Cp*2MX ( X = Cl, Br, Me) exhibit structural features that vary significantly depending on the size and electronegativity of the central atom. While salt metathesis, halide abstraction and methanide abstraction methods represent viable routes for the preparation of salts of Cp*B-2(+) and Cp*Al-2(+), acidolysis of a Cp* group from Cp*Ga-3 is the most reliable method for the synthesis of the analogous gallium cation. Gallocenium cations are less stable than either of the lighter congeneric cations since they prove to be susceptible to decomposition reactions involving the "back-transfer" of ligands from the counter anion. Density functional theory (DFT) calculations revealed that, whereas Cp*Ga-2(+) is predicted to adopt a molecular structure more similar to that of Cp*B-2(+), the electronic structure of the gallium cation bears a greater resemblance to that of Cp*Al-2(+).Chemistr

C II abundances in early-type stars: solution to a notorious non-LTE problem

We address a long-standing discrepancy between non-LTE analyses of the prominent C II 4267 and 6578/82 A multiplets in early-type stars. A comprehensive non-LTE model atom of C II is constructed based on critically selected atomic data. This model atom is used for an abundance study of six apparently slow-rotating main-sequence and giant early B-type stars. High-resolution and high-S/N spectra allow us to derive highly consistent abundances not only from the classical features but also from up to 18 further C II lines in the visual - including two so far unreported emission features equally well reproduced in non-LTE. These results require the stellar atmospheric parameters to be determined with care. A homogeneous (slightly) sub-solar present-day carbon abundance from young stars in the solar vicinity (in associations and in the field) of log C/H +12= 8.29+/-0.03 is indicated.Comment: 8 pages, 5 figure

Is there a link between self-perceived stress and physical activity levels in Scottish adolescents?

Purpose It is becoming more evident that Physical Activity (PA) has a moderating effect on the negative health consequences of excessive psycho-social stress (Stults-Kolehmainen & Sinha, 2014). Recent literature has highlighted that the relationship between stress and physical activity is bidirectional (Stults-Kolehmainen & Sinha, 2014). Furthermore, it has been suggested that the stress response impedes levels of participation in PA (Lutz, Stults-Kolehmainen, & Bartholomew, 2010). However, the impacts of accumulating life stress on PA remain under-investigated. Aims: i. To determine if significant differences exist in uptake of PA between adolescents who have experienced high life stress, in comparison to those who have not ii. To investigate the relationship between perceived stress in adolescents and PA. iii. To investigate whether high life stress can explain differences in other health behaviours, such as smoking and alcohol consumption Methods A purposive sampling strategy was employed. Adolescents from a low SES background who had experienced extensive life stress, were compared with more economically-affluent matched-controls. PA patterns were measured using the ‘Physical Activity Questionnaire for High School (PAQA)’(Kowalski, Crocker, & Kowalski, 1997) Stress scores were assessed using the 10 item version of the perceived stress scale (PSS-10). Statistical analysis was conducted Findings PA scores were significantly different between groups (p˂0.05), with the low SES group significantly less active every day (p˂0.05) except on Saturdays (Mann-Whitney U= 31.0, Z=-1.594, p = ˃0.05). Furthermore, Spearman’s correlation showed a negative relationship between total stress levels and PA during spare time ( rs = -0.61,n=10, p= ˂0.05). A similar relationship was evident for: PA levels during lunchtime, (rs = -0.69, n= 10, p= ˂0.05), evenings ( rs = -0.57, n= 10, p = ˂0.05) and for overall PA over a seven day period (rs =0.81, n = 10, p= ˂0.05). Conclusion These findings add to existing evidence suggesting stress, during adolescent transition periods, impedes PA uptake. Physical Educators should incorporate the stress remediating effects of PA into school practice, and strive to inculcate leisure-based physical activities promoting sustainable PA, especially with adolescents likely to have been exposed to excessive stress loads during critical developmental periods

The interaction between transpolar arcs and cusp spots

Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic flux and results in a "wedge" of closed flux which remains trapped, embedded in the magnetotail lobe. The cusp spot is an indicator of lobe reconnection at the high-latitude magnetopause; in its simplest case, lobe reconnection redistributes open flux without resulting in any net change in the open flux content of the magnetosphere. We present observations of the two phenomena interacting--i.e., a transpolar arc intersecting a cusp spot during part of its lifetime. The significance of this observation is that lobe reconnection can have the effect of opening closed magnetotail flux. We argue that such events should not be rare