10,523 research outputs found
Can the Archaeology of Manual Specialization Tell Us Anything About Language Evolution? A Survey of the State of Play
In this review and position paper we explore the neural substrates for manual specialization and their possible connection with language and speech. We focus on two contrasting hypotheses of the origins of language and manual specialization: the language-first scenario and the tool-use-first scenario. Each one makes specific predictions about hand-use in non-human primates, as well as about the necessity of an association between speech adaptations and population-level right-handedness in the archaeological and fossil records. The concept of handedness is reformulated for archaeologists in terms of manual role specialization, using Guiard's model asymmetric bimanual coordination. This focuses our attention on skilled bimanual tasks in which both upper limbs play complementary roles. We review work eliciting non-human primate hand preferences in co-ordinated bimanual tasks, and relevant archaeological data for estimating the presence or absence of a population-level bias to the right hand as the manipulator in extinct hominin species and in the early prehistory of our own species
Mental health and developmental disorders in infancy and early childhood. The PDM-2
We provide a general introduction to the theoretical and empirical sources informing the development of the Infancy and Early Childhood Section (IEC) of the second edition of the Psychodynamic Diagnostic Manual (PDM-2). We offer a brief exploration of the evolution of developmental psychoanalysis and its applications to infant mental health, along with an example of applying the IEC framework to clinical and developmental data from a longitudinal study based on developmental and psychodynamic principles. This article illustrates the evolution of theory in the context of interdisciplinary integration and explores its implications for diagnosis and clinical formulatio
Massless Scalar Field Propagator in a Quantized Space-Time
We consider in detail the analytic behaviour of the non-interacting massless
scalar field two-point function in H.S. Snyder's discretized non-commuting
spacetime. The propagator we find is purely real on the Euclidean side of the
complex plane and goes like as from either the
Euclidean or Minkowski side. The real part of the propagator goes smoothly to
zero as increases to the discretization scale and remains zero
for . This behaviour is consistent with the termination of
single-particle propagation on the ultraviolet side of the discretization
scale. The imaginary part of the propagator, consistent with a
multiparticle-production branch discontinuity, is finite and continuous on the
Minkowski side, slowly falling to zero when . Finally, we
argue that the spectral function for the multiparticle states appears to
saturate as probes just beyond the discretization scale. We
speculate on the cosmological consequences of such a spectral function.Comment: 6 pages, 1 eps figure embedded in manuscrip
Human response to vibration in residential environments (NANR209), technical report 2: measurement of response
Based on a review of the literature and the best practice guidance available, a social survey questionnaire was developed to measure residents’ self-reported annoyance and to provide data suitable for establishing exposure-response relationships between levels of annoyance and levels of vibration. The development of the questionnaire was influenced by a number of previous studies such as: the social survey questionnaire developed for the NANR172 Pilot Study of this research (Defra, 2007); best practice guidelines for the development of socio-acoustic surveys issued by ICBEN and presented in the current International Standard (Fields et al., 2001; ISO/TS 15666:2003); the Nordtest Method (2001) for the development of socio-vibration surveys, and a peer review of the social survey questionnaire by international experts in the field. In order to avoid influencing responses and reasons for participation in the research, the survey was introduced as a survey of neighbourhood satisfaction. The questionnaire design, through the use of sections, enables new sections to be added to the questionnaire so that specific vibration sources can be investigated in more depth. In addressing the ‘response’ component in the ‘exposure-response’ relationship, the questionnaire was designed to yield interval-level measurement data suitable for analysis with vibration measurement data via two response scales: the five-point semantic and the eleven-point numerical scales. This decision was largely founded upon the ability of the two scales to meet the criteria established by ICBEN (Fields et al., 2001) for socio-acoustic survey design. Detailed procedures were documented, following the field trial of the questionnaire, in terms of the role of the interviewer, the recording of information and the transfer of the data to the relevant database for subsequent analysis and to inform the vibration team responsible for the ‘exposure’ component of this research project
MaineCare—A Provider Prospective
Dr. Erik Steele in this commentary discusses MaineCare (Maine’s Medicaid program) from a provider’s perspective. He suggests that delays and problems in the state’s reimbursement to providers have led to doubts about the state’s credibility both as a payer and as a health care systems change leader
Exactness of the Bogoliubov approximation in random external potentials
We investigate the validity of the Bogoliubov c-number approximation in the
case of interacting Bose-gas in a \textit{homogeneous random} media. To take
into account the possible occurence of type III generalized Bose-Einstein
condensation (i.e. the occurrence of condensation in an infinitesimal band of
low kinetic energy modes without macroscopic occupation of any of them) we
generalize the c-number substitution procedure to this band of modes with low
momentum. We show that, as in the case of the one-mode condensation for
translation-invariant interacting systems, this procedure has no effect on the
exact value of the pressure in the thermodynamic limit, assuming that the
c-numbers are chosen according to a suitable variational principle. We then
discuss the relation between these c-numbers and the (total) density of the
condensate
A preliminary assessment of small steam Rankine and Brayton point-focusing solar modules
A preliminary assessment of three conceptual point-focusing distributed solar modules is presented. The basic power conversion units consist of small Brayton or Rankine engines individually coupled to two-axis, tracking, point-focusing solar collectors. An array of such modules can be linked together, via electric transport, to form a small power station. Each module also can be utilized on a stand-alone basis, as an individual power source
Disc loss and renewal in A0535+26
This paper presents observations of the Be/X-ray binary system A0535+26
revealing the first observed loss of its circumstellar disc, demonstrated by
the loss of its JHK infrared excess and optical/IR line emission. However
optical/IR spectroscopy reveals the formation of a new inner disc with
significant density and emission strength at small radii; the disc has proven
to be stable over 5 months in this intermediate state.Comment: 4 pages, 4 figures, accepted by MNRAS, uses mn.st
Imaging Transport Resonances in the Quantum Hall Effect
We use a scanning capacitance probe to image transport in the quantum Hall
system. Applying a DC bias voltage to the tip induces a ring-shaped
incompressible strip (IS) in the 2D electron system (2DES) that moves with the
tip. At certain tip positions, short-range disorder in the 2DES creates a
quantum dot island in the IS. These islands enable resonant tunneling across
the IS, enhancing its conductance by more than four orders of magnitude. The
images provide a quantitative measure of disorder and suggest resonant
tunneling as the primary mechanism for transport across ISs.Comment: 4 pages, 4 figures, submitted to PRL. For movies and additional
infomation, see http://electron.mit.edu/scanning/; Added scale bars to
images, revised discussion of figure 3, other minor change
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