772 research outputs found
The Humanism of Herbert Read
As readers of the Social Theory Caucus Bulletin, you are probably, by and large, more familiar with Herbert Read\u27s views on art education than others in our field. One would expect that you are also generally more sympathetic with his theoretical orientation as well as more aware of the relevance of his work to current educational concerns. This essay will focus on the historical basis of Read\u27s moral ideas, and their implications for the work that lies ahead for this group of socially concerned art educators
The Limits of Linear Modes of Inquiry into Naturalistic World-Views: A Case Study of Cherokee Culture
We begin with the cultural-anthropological assumption that a people’s world-view is based in concepts of time and process, and is reflected in the ceremonies, customs, rituals, and other traditional patterns of social conduct within the society. In a case study of the Native American Cherokee, linear modes of inquiry, characteristic of Western science, are shown to be limited in their capacity to examine and appreciate these dimensions of culture in pre-literate societies. It is suggested that those aspects of our own culture which are grounded in aesthetic value may also be relatively inaccessible for the same reason. By examining meanings of time and process in Cherokee culture, we discover traditions of life processed occurring within cyclical rhythms of nature as well as a sense of personal identity. The hope is that, armed with such awareness, we may be better able to move beyond a confining ethnocentrisms toward a more comprehensive understanding of our selves within a world-view that is more integrated and participatory
Seeing Eye to I: Perceptual Development and Sense of Self
This paper is a commentary on current views of early development in art and argues for a theory which emphasizes a more active role of the learner in the refinement of perceptual ability, particularly in drawing development. Independent perception is presented as a primary source of children\u27s visual imagery: and inference and problem solving, rather than imitation, are seen to characterize the drawing process as well as to indicate proper methods of instruction. Discussion also considers the shift away from inquiry in this area
Insulator-to-metal transition in sulfur-doped silicon
We observe an insulator-to-metal (I-M) transition in crystalline silicon
doped with sulfur to non- equilibrium concentrations using ion implantation
followed by pulsed laser melting and rapid resolidification. This I-M
transition is due to a dopant known to produce only deep levels at equilibrium
concentrations. Temperature-dependent conductivity and Hall effect measurements
for temperatures T > 1.7 K both indicate that a transition from insulating to
metallic conduction occurs at a sulfur concentration between 1.8 and 4.3 x
10^20 cm-3. Conduction in insulating samples is consistent with variable range
hopping with a Coulomb gap. The capacity for deep states to effect metallic
conduction by delocalization is the only known route to bulk intermediate band
photovoltaics in silicon.Comment: Submission formatting; 4 journal pages equivalen
Low contrast visual acuity testing is associated with cognitive performance in multiple sclerosis: a cross-sectional pilot study
Background: Cognitive impairment and visual deterioration are two key clinical symptoms in MS and affect 50 to 80% of patients. Little is known about the influence of cognitive impairment on visual tests recommended for MS such as low contrast sensitivity testing. Our objective was to investigate whether low contrast sensitivity testing is influenced by cognitive impairment in multiple sclerosis (MS) patients. Methods: Cross-sectional study including 89 patients with relapsing-remitting MS. All patients received cognitive evaluation using Rao’s Brief Repeatable Battery of Neuropsychological Testing (BRB-N). Visual assessments included low contrast sensitivity (CS) by functional acuity contrast testing and high contrast visual acuity (VA) using ETDRS charts. Retinal morphology as visual impairment correlate was measured using retinal nerve fiber layer (RNFL) thickness by optical coherence tomography. Results: In combined analyses using generalized estimating equation models, Paced Auditory Serial Addition Test (PASAT) and RNFL as well as and the Symbol Digit Modalities Test (SDMT) and RNFL predicted CS. To further control for a potential influence of the anterior visual system we performed partial correlation analyses between visual function and cognitive function test results but controlling for RNFL. Even when controlling for RNFL, CS was associated with PASAT performance and SDMT performance. Conclusion: Our data show that: a) cognitive impairment and performance in visual function tests such as low contrast sensitivity testing are associated; b) the main cognitive domains correlating with visual test performance are information processing speed and, to a lesser degree, memory; This preliminary data needs to be substantiated in further studies investigating patients with a higher cognitive burden, healthy controls and in longitudinal settings
Adaptive partitioning of real-time tasks on multiple processors
This paper presents a new algorithm for scheduling real-time tasks on multiprocessor/multicore systems. This new algorithm is based on combining EDF scheduling with a migration strategy that moves tasks only when needed. It has been evaluated through an extensive set of simulations that showed good performance when compared with global or partitioned EDF: a worst-case utilisation bound similar to partitioned EDF for hard real-time tasks, and a tardiness bound similar to global EDF for soft real-time tasks. Therefore, the proposed scheduler is effective for dealing with both soft and hard real-time workloads
Anomalous f-electron Hall Effect in the Heavy-Fermion System CeTIn (T = Co, Ir, or Rh)
The in-plane Hall coefficient of CeRhIn, CeIrIn, and
CeCoIn and their respective non-magnetic lanthanum analogs are reported
in fields to 90 kOe and at temperatures from 2 K to 325 K. is
negative, field-independent, and dominated by skew-scattering above 50 K
in the Ce compounds. becomes increasingly negative below 50 K
and varies with temperature in a manner that is inconsistent with skew
scattering. Field-dependent measurements show that the low-T anomaly is
strongly suppressed when the applied field is increased to 90 kOe. Measurements
on LaRhIn, LaIrIn, and LaCoIn indicate that the same
anomalous temperature dependence is present in the Hall coefficient of these
non-magnetic analogs, albeit with a reduced amplitude and no field dependence.
Hall angle () measurements find that the ratio
varies as below 20 K for all
three Ce-115 compounds. The Hall angle of the La-115 compounds follow this
T-dependence as well. These data suggest that the electronic-structure
contribution dominates the Hall effect in the 115 compounds, with -electron
and Kondo interactions acting to magnify the influence of the underlying
complex band structure. This is in stark contrast to the situation in most
and heavy-fermion compounds where the normal carrier contribution to the
Hall effect provides only a small, T-independent background to Comment: 23 pages and 8 figure
Understanding the History of Two Complex Ice Crystal Habits Deduced From a Holographic Imager
The sizes and shapes of ice crystals influence the radiative properties of clouds, as well as precipitation initiation and aerosol scavenging. However, ice crystal growth mechanisms remain only partially characterized. We present the growth processes of two complex ice crystal habits observed in Arctic mixed-phase clouds during the Ny-Ålesund AeroSol Cloud ExperimeNT campaign. First, are capped-columns with multiple columns growing out of the plates' corners that we define as columns on capped-columns. These ice crystals originated from cycling through the columnar and plate temperature growth regimes, during their vertical transport by in-cloud circulation. Second, is aged rime on the surface of ice crystals having grown into faceted columns or plates depending on the environmental conditions. Despite their complexity, the shapes of these ice crystals allow to infer their growth history and provide information about the in-cloud conditions. Additionally, these ice crystals exhibit complex shapes and could enhance aggregation and secondary ice production
Integrating microbial physiology and physio-chemical principles in soils with the MIcrobial-MIneral Carbon Stabilization (MIMICS) model
A growing body of literature documents the pressing need to develop soil
biogeochemistry models that more accurately reflect contemporary
understanding of soil processes and better capture soil carbon (C) responses
to environmental perturbations. Models that explicitly represent microbial
activity offer inroads to improve representations of soil biogeochemical
processes, but have yet to consider relationships between litter quality,
functional differences in microbial physiology, and the physical protection
of microbial byproducts in forming stable soil organic matter (SOM). To
address these limitations, we introduce the MIcrobial-MIneral Carbon
Stabilization (MIMICS) model, and evaluate it by comparing site-level soil C
projections with observations from a long-term litter decomposition study and
soil warming experiment. In MIMICS, the turnover of litter and SOM pools is
governed by temperature-sensitive Michaelis–Menten kinetics and the activity
of two physiologically distinct microbial functional types. The production of
microbial residues through microbial turnover provides inputs to SOM pools
that are considered physically or chemically protected. Soil clay content
determines the physical protection of SOM in different soil environments.
MIMICS adequately simulates the mean rate of leaf litter decomposition
observed at temperate and boreal forest sites, and captures observed effects
of litter quality on decomposition rates. Moreover, MIMICS better captures
the response of SOM pools to experimental warming, with rapid SOM losses but
declining temperature sensitivity to long-term warming, compared
with a more conventional
model structure. MIMICS incorporates current microbial theory to explore the
mechanisms by which litter C is converted to stable SOM, and to improve
predictions of soil C responses to environmental change
Weak localization in InSb thin films heavily doped with lead
The paper reports on the investigations of the weak localization (WL) effects
in 3D polycrystalline thin films of InSb. The films are closely compensated
showing the electron concentration n>10^{16} cm^{-3} at the total concentration
of the donor and acceptor type structural defects >10^{18} cm^{-3}. Unless
Pb-doped, the InSb films do not show any measurable or show very small WL
effect at 4.2 K. The Pb-doping to the concentration of the order of 10^{18}
cm^{-3} leads to pronounced WL effects below 7 K. In particular, a clearly
manifested SO scattering is observed. From the comparison of the experimental
data on temperature dependence of the magnetoresistivity and sample resistance
with the WL theory, the temperature dependence of the phase destroying time is
determined. The determination is performed by fitting theoretical terms
obtained from Kawabata's theory to experimental data on magnetoresistance. It
is concluded that the dephasing process is connected to three separate
interaction processes. The first is due to the SO scatterings and is
characterized by temperature-independent relaxation time. The second is
associated with the electron-phonon interaction. The third dephasing process is
characterized by independent on temperature relaxation time tau_c. This
relaxation time is tentatively ascribed to inelastic scattering at extended
structural defects, like grain boundaries. The resulting time dephasing time
shows saturation in its temperature dependence. The temperature dependence of
the resistance of the InSb films can be explained by the electron-electron
interaction for T2 K.Comment: 15 pages with 5 figure
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