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The focus is on developmental effects of communication technologies from print literacy to Internet and smart phones. Longitudinal and cross-sectional comparison sheds light on historical shifts and cross-cultural data. Because there is no evidence that basic media effects are country or ethnicity specific, evidence from multiple countries shows how the historical march of media have affected values, learning environments, and individual development. Cross-cultural evidence suggests that this is indeed a portrait of globalized social change and its implications for human development around the world. Nonetheless, I provide an example of how the global culture engendered by new communications technologies is expressed. Using a theory of social change and human development as a framework I explore developmental implications - social, cognitive, and neural - of the march of media through historical time and across geographical space. Eschewing methodocentrism, I draw on studies employing a variety of methods: content analysis, focus group, survey, field experiment, lab experiment, and fMRI experiment. While before-after comparisons are precious but rare, there are many other research designs that allow us to infer effects of the historical introduction and expansion of a particular communication technology.
The study of the exploitation of animals for traction in prehistoric Europe has been linked to the ‘secondary products revolution’. Such an approach, however, leaves little scope for identification of the less specialised exploitation of animals for traction during the European Neolithic. This study presents zooarchaeological evidence—in the form of sub-pathological alterations to cattle foot bones—for the exploitation of cattle for the occasional pulling of heavy loads, or ‘light’ traction. The analysis and systematic comparison of material from 11 Neolithic sites in the Western Balkans (c. 6100–4500 cal BC) provides the earliest direct evidence for the use of cattle for such a purpose.
We have defined the complex bed topography for a section of a small temperate glacier using 50 MHz monostatic short-pulse radar data and a synthetic-aperture array-processing method. The data were collected on a 100 m by 340 m array grid in the upper stem of Gulkana Glacier, central Alaska, U.S.A. The array processing was based on a modified three-dimensional (3-D) Kirchhoff migration integral and implemented with a synthetic-aperture approach that uses sequences of overlapping sub-arrays to generate depth images in vertical planes. Typical sub-array beam patterns are generally <5° at the −6 dB level, giving a flashlight-like searching capability without distorting the wavelet shape. The bed topography was constructed using normal reflections picked from 3-D array depth images. In some instances reflections were imaged outside the data-cover-age area. The bed surface dips steeply, both parallel and transverse to the direction of ice flow. The maximum observed depth is roughly 140 m. The 3-D method resolved bed dips up to 45°. In regions of steepest dip, it improved depth accuracy by 36% compared with raw data, and by 15% compared with standard two-dimensional (2-D) migration. Over 12 dB of signal-to-noise improvement and improved spatial resolution was achieved compared to raw data and 2-D migration. False bottom layering seen in the raw data and in 2-D migrations is not observed in the 3-D array results. Furthermore, loss of bottom reflections is shown by the 3-D migration to be attributable to the dip and curvature of the reflector, and not scattering losses or signal clutter from englacial inclusions.
Background: Many Canadians with multiple sclerosis (MS) have recently travelled internationally to have procedures for a putative condition called chronic cerebrospinal venous insufficiency (CCSVI). Here, we describe where and when they went and describe the baseline characteristics of persons with MS who participated in this non–evidence-based medical tourism for CCSVI procedures. Methods: We conducted a longitudinal observational study that used online questionnaires to collect patient-reported information about the safety, experiences, and outcomes following procedures for CCSVI. A convenience sample of all Albertans with MS was recruited between July 2011 and March 2013. Results: In total, 868 individuals enrolled; 704 were included in this cross-sectional, baseline analysis. Of these, 128 (18.2%) participants retrospectively reported having procedures for CCSVI between April 2010 and September 2012. The proportion of participants reporting CCSVI procedures declined from 80 (62.5%) in 2010, to 40 (31.1%) in 2011, and 8 (6.3%) in 2012. In multivariable logistic regression analysis, CCSVI procedures were independently associated with longer disease duration, secondary progressive clinical course, and greater disability status. Conclusions: Although all types of people with MS pursued procedures for CCSVI, a major driver of participation was greater disability. This highlights that those with the greatest disability are the most vulnerable to unproven experimental procedures. Participation in CCSVI procedures waned over time possibly reflecting unmet expectations of treated patients, decreased media attention, or that individuals who wanted procedures had them soon after the CCSVI hypothesis was widely publicized.
Although the important roles and functions of Latin American cities have received recognition and discussion in historical writing, there exist few empirically grounded and detailed investigations of individual urban centers. Thus, reviewing the nature of historical research on Latin American urbanization, Sofer and Szuchman (1979: 113, 119) noted the dearth of quantitative investigations of the social dimensions of urban existence, as well as a reliance on aggregate data as opposed to such primary documentation as manuscript census returns, notarial records, and judicial assessments. They conclude that “historians have been reticent to explore the social data in primary documentation and join them with non-quantifiable sources of information in order to reach an existential understanding of the Latin American past.” Similarly, Socolow and Johnson (1981: 51) have pointed to the need for research concentrating on the “social, economic, and physical structure of individual cities and groups of cities.”
The influence of alkaline degradation or radiolytic degradation of asphalt
on plutonium solubility has been investigated. Asphalt has been contacted
with water, sodium hydroxide solution or concrete leachate at 80°C for
periods of up to approximately 2 years. Sodium nitrate was also present in
some of the experiments. Plutonium solubilities were measured at pH 12 in
the leachates and found to be less than 10-8 mol dm-3
for most degradations. Relatively low levels of Total Organic Carbon were
measured in the leachates. Alpha radiolysis of asphalt in the presence of
concrete and water has also been studied. Samples of asphalt were
encapsulated in concrete after coating with the
238PuO2, crushed and leached at room temperature.
The solubility of plutonium was measured in samples of the leachates after
approximately 90 days and 180 days had elapsed. The results showed that the
solubility of plutonium in the α-radiolysis leachates remained low and was
in the range 2 × 10-11 to 8 × 10-9 mol
dm-3. A consideration of these results, and data published
elsewhere, suggests that chemical and radiolytic attack on asphalt or
bitumen under anaerobic, alkaline conditions typical of a deep cementitious
repository is unlikely to generate complexants for plutonium which are
effective at high pH. Any enhancement of plutonium solubility is likely to
be less significant than that arising from the degradation of some other
Nirex is seeking to develop a deep underground repository for the disposal of solid intermediate-level and low-level radioactive wastes (ILW and LLW) in the UK. One possible influence on the behaviour of radionuclides is the formation of water-soluble complexants by the degradation of the solid organic polymers that will be present in the wastes. The degradation products of cellulose have been shown to increase the solubility of plutonium and other radionuclides and to reduce sorption onto near-field and far-field materials. Degradation of cellulose under anaerobic alkaline conditions produces a range of organic acids. In this paper 2-C-(hydroxymethyl)-3-deoxy-D-pentonic acid (isosaccharinic acid, ISA) is identified by High Performance Liquid Chromatography as a significant component of cellulose leachates. A combination of fractionation of cellulose leachates and plutonium solubility determinations shows that ISA is responsible for the majority of the enhancement of plutonium solubility observed in such leachates. Further degradation of ISA by chemical or microbial action may lessen the effect of degraded cellulose leachates. Experimental studies on the chemical degradation of this compound under alkaline conditions suggest that the presence of oxygen is required. Microbial degradation studies show that the plutonium solubility in solutions of ISA is reduced by their exposure to microbial action.
The mineral schreibersite, (Fe,Ni)3P, a ubiquitous component of iron meteorites, is known to undergo anoxic hydrolytic modification to afford a range of phosphorus oxyacids. H-phosphonic acid (H3PO3) is the principal hydrolytic product under hydrothermal conditions, as confirmed here by 31P-NMR spectroscopic studies on shavings of the Seymchan pallasite (Magadan, Russia, 1967), but in the presence of photochemical irradiation a more reduced derivative, H-phosphinic (H3PO2) acid, dominates. The significance of such lower oxidation state oxyacids of phosphorus to prebiotic chemistry upon the early Earth lies with the facts that such forms of phosphorus are considerably more soluble and chemically reactive than orthophosphate, the commonly found form of phosphorus on Earth, thus allowing nature a mechanism to circumvent the so-called Phosphate Problem.
This paper describes the Galvanic corrosion of Fe3P, a hydrolytic modification pathway for schreibersite, leading again to H-phosphinic acid as the key P-containing product. We envisage this pathway to be highly significant within a meteoritic context as iron meteorites are polymetallic composites in which dissimilar metals, with different electrochemical potentials, are connected by an electrically conducting matrix. In the presence of a suitable electrolyte medium, i.e., salt water, galvanic corrosion can take place. In addition to model electrochemical studies, we also report the first application of the Kelvin technique to map surface potentials of a meteorite sample that allows the electrochemical differentiation of schreibersite inclusions within an Fe:Ni matrix. Such experiments, coupled with thermodynamic calculations, may allow us to better understand the chemical redox behaviour of meteoritic components with early Earth environments.
We propose that some aspects of language – notably intersubjectivity – evolved to fit the brain, whereas other aspects – notably grammar – co-evolved with the brain. Cladistic analysis indicates that common basic structures of both action and grammar arose in phylogeny six million years ago and in ontogeny before age two, with a shared prefrontal neural substrate. In contrast, mirror neurons, found in both humans and monkeys, suggest that the neural basis for intersubjectivity evolved before language. Natural selection acts upon genes controlling the neural substrates of these phenotypic language functions.
Analgesics and anaesthetics have diverse synaptic actions that nonetheless have a common net inhibitory action on neuronal discharge. It is puzzling, therefore, that these two classes of compounds have fundamentally different affects, one blocking pain and the other consciousness. Indeed, beyond the isolated synapse, little is known of the larger scale mechanisms that mediate actual function, for example, transient neuronal assemblies. It was hypothesized that the two classes of drugs might have, respectively, differential effects on transient activation of these assemblies of neurons working together.
Hippocampal tissue from juvenile Wistar rats was used for in vitro optical imaging with voltage-sensitive dyes and simultaneous field potential recordings. The response to paired pulse stimulation of the hippocampus was recorded in the presence and absence of two types of analgesic (morphine and gabapentin) and two types of anaesthetic (thiopental and propofol).
Optical imaging and electrophysiology used in parallel yield quite different results. Most consistently, the imaging technique was able to detect an enhanced period of activation following anaesthetic, but not analgesic application. This effect was not readily seen from electrophysiology field potential recordings.
These findings suggest that, irrespective of the effects of the two drug classes at a synaptic level, the dynamics of transient neuronal assemblies are modified selectively by anaesthetics and not analgesics.
Prescribing Analysis and Cost (PACT) data are sent to all GPs to assist them in monitoring their prescribing. Although the quarterly Standard Reports contain a great deal of information it is not known how GPs make use of it. This paper reports on two linked studies which explore GPs' views on PACT Standard Reports and PACT catalogue data. In the first study, interviews were carried out with 21 GPs in 16 practices selected according to criteria related to their prescribing budget. The interview schedule included questions on how the Standard Reports were used and the amount and ease of understanding of the information provided, and on use of PACT Catalogue data. The second study was a questionnaire survey of the 1047 practices in the West Midlands region in which GPs were asked how they used PACT data. Analysis of the interviews showed that GPs' views on the Standard Report varied widely although most found it helpful. Many GPs used the data in a limited way and only used a small part of them. Single-handed GPs and small practices were least likely to make use of PACT data and few practices analysed the data in any depth. Most respondents said that comparing their costs with health authority and national averages was useful for considering where to make changes in their prescribing. GPs indicated they would like the report to include some interpretation of the data with suggestions for changes which could be made. The regional survey confirmed that PACT Standard Reports are only used in a limited way and how they are used varies with practice size. We conclude that PACT Standard Reports were rarely used to analyse prescribing in any depth and GPs need more support in making better use of the data.
Higher rates of alcohol use have been reported in HIV+ individuals
compared to the general population. Both heavy alcohol use and HIV
infection are associated with increased risk of neuropsychological (NP)
impairment. We examined effects of heavy active alcohol use and HIV on
NP functioning in a large sample of community-residing HIV+ individuals
and HIV− controls. The four main study groups included 72
HIV− light/non-drinkers, 70 HIV− heavy drinkers
(>100 drinks per month), 70 HIV+ light/non-drinkers, and 56 HIV+
heavy drinkers. The heavy drinking group was further subdivided to
assess effects of the heaviest levels of active alcohol use (>6
drinks per day) on NP functioning. A comprehensive NP battery was
administered. Multivariate analysis of covariance was employed to
examine the effect of HIV and alcohol on NP functioning after adjusting
for group differences in age and estimated premorbid verbal
intellectual functioning. The analyses identified main effects of heavy
drinking and HIV on NP function, with greatest effects involving the
contrast of HIV+ heavy drinkers and the HIV− light drinkers.
Synergistic effects of heaviest current drinking and HIV infection were
identified in analyses of motor and visuomotor speed. Supplementary
analyses also revealed better NP function in the HIV+ group with
antiretroviral treatment (ART) and lower level of viral burden, a
finding that was consistent across levels of alcohol consumption.
Finally, heavy alcohol use and executive functioning difficulties were
associated with lower levels of self-reported medication adherence in
the HIV+ group. The findings suggest that active heavy alcohol use and
HIV infection have additive adverse effects on NP function, that they
may show synergistic effects in circumstances of very heavy active
alcohol use, and that heavy drinking and executive functioning may
mediate health-related behaviors in HIV disease. (JINS, 2005,