Average electron density profiles in the plasmasphere between L = 1.4 and 3.2 deduced from whistlers

985 whistlers recorded at Tihany, Hungary (L = 1.9) between December 1970 and May 1975 have been processed for equatorial crossing radius L, equatorial electron density n_eq and tube electron content N_T. The obtained L values lie in the range L = 1.4-3.2. The median values of n_eq and N_T as a function of L fit well to the density profiles published by Park et al. The results also indicate that at lower L values the whistlers are ducted by stronger density enhancements.     

LHR whistlers and lhr spherics in the outer ionosphere

Special types of VLF signals, which follow whistlers and spherics and have an anomalous dispersion near the lower hybrid resonance (LHR) frequency, have been observed on the low-altitude Intercosmos satellites. These signals have been named LHR whistlers and LHR spherics, respectively. A mechanism is suggested for the formation of their spectra, based on the peculiarities of quasi-resonance wave propagation at frequencies near the LHR frequencies. It is shown that the large dispersion observed may be accounted for by a significant increase in the propagation time of the wave as its frequency approaches the maximum in the LHR frequency profile.     

Nodes and edges: A network approach to hierarchisation and state formation in Japan

This paper argues that the centralised hierarchy that emerged at the beginning of the Kofun (mounded tomb) period in Japan can be explained by the locations that the polities to be hierarchised occupy and the differences in the topological potentials that these locations generate. Previous attempts of explaining the phenomenon by attributing its cause to factors such as differential access to resources and control over their distribution have been proven not to fit with the available body of evidence. The application of social network analysis-derived concepts and methods reveals that the topological locations that polities occupied generated different centralities, i.e. different degrees of connectedness to other polities and of mediating interactions between polities, which led to the hierarchisation and centralisation of their relationships. The paper concludes that the topological structure of a social network itself can be a significant cause of its own hierarchisation, and it compares the finding with the manner in which the concepts of agency and power are applied to the explanation of social hierarchisation and centralisation.     

Propagation characteristics of night-time whistlers in the region of equatorial anomaly

In this paper results of simultaneous multi-station observations of night-time whistlers obtained at very low latitudes for the last three years are presented. The propagation mechanism of these whistlers is also discussed. Some records can be shown to have the characteristics of ducted propagation by calculating the dispersion of the whistlers along a ducted path and by noticing the feature of strong intensity, as well as the existence of three-hop echoes. Whistlers in some other records, however, can be shown to be propagating along a non-ducted path by numerical ray-tracing, in which a non-dipole field (IGRF) is used and a negative horizontal gradient of ionization in the equatorial ionosphere is taken into account. The agreement of the results of calculation with observed facts seems to confirm the existence of a definite whistler path at very low latitudes. Finally, based on analysis of typical events, the effects of magnetic storms on the parameters of low latitude whistlers due to variations in the equatorial ionosphere are also discussed.     

Association of whistlers with lightning discharges on the Earth and on Jupiter

The association between whistlers and lightning discharges has been reviewed on the basis of terrestrial ionospheric satellite observations of VLF radio noise. Evidence indicating that the observed low-latitude radio noise is associated with thunderstorms includes (1) amplitude distribution and noise properties, (2) geographical location, (3) diurnal variation in activity, and (4) diurnal variation of frequency spectrum. Corresponding studies on the propagation of sferics in the ionosphere and the excitation of whistlers recently carried out for Jupiter are presented here and compared with the terrestrial studies.     

An asymmetry in the direction of arrival of whistlers at Sanae,Antarctica

The directions of arrival of over 1300 whistlers have been measured at Sanae, Antarctica and it is shown that whistlers arriving from lower latitudes than the station predominantly come from the west. In this paper we report on the observations and discuss the possible reasons for this asymmetric distribution of arrival bearings.     

The polarisation of whistlers received on the ground near L = 4

The observed polarisation of the horizontal magnetic components of whistler mode signals received at Halley, Antarctica (L≈ 4.3), is in many cases that expected from a simple model of the transionospheric and sub-ionospheric propagation in the southern hemisphere; i.e. right-hand elliptical (field vectors rotate clockwise, looking towards the source) for ionospheric exit points close to the receiver, tending towards linear for more distant exit points. This suggests it may be possible to use the observed polarisation to estimate the propagation distance. However, in other cases, in certain frequency ranges, left-hand elliptically polarised signals have been observed. More realistic models do predict polarisation reversals at certain frequencies and exit point to receiver distances, but not over such a wide frequency range as has sometimes been observed. Also, in some cases, signals with nearly right-hand circular polarisation have been observed for exit points at large distances where linear polarisation would be expected.     

A new approach to the tympanum of Neuilly-en-Donjon

Romanesque sculpture can be profitably studied by trying to create the thought processes of those responsible for designing the programs. In particular, the thought pattern of associating various biblical stories which contain the same or similar words can be applied to the program of the little church of Neuilly-en-Donjon (Allier). It is clear that the various stories depicted are related to one another by sound - for example the Adoration of the Magi and the fall of Simon Magus and Mary Magdalen at the house of Simon the Pharisee. However, just as the genius of a monastic author such as Bernard of Clairvaux was the thematic unity he could use to organize these aural associations, so does the importance of the program at Neuilly derive from the sophisticated thematic unity of the program around the theological virtue of faith. From this study, we can learn not only to appreciate the genius of the designer of the program at Neuilly but also to attempt to unlock other secrets of Romanesque sculpure by applying this or other elements of contemporary thought processes to the parts of a program.     

A new approach to the tympanum of Neuilly-en-Donjon

Romanesque sculpture can be profitably studied by trying to create the thought processes of those responsible for designing the programs. In particular, the thought pattern of associating various biblical stories which contain the same or similar words can be applied to the program of the little church of Neuilly-en-Donjon (Allier). It is clear that the various stories depicted are related to one another by sound - for example the Adoration of the Magi and the fall of Simon Magus and Mary Magdalen at the house of Simon the Pharisee. However, just as the genius of a monastic author such as Bernard of Clairvaux was the thematic unity he could use to organize these aural associations, so does the importance of the program at Neuilly derive from the sophisticated thematic unity of the program around the theological virtue of faith. From this study, we can learn not only to appreciate the genius of the designer of the program at Neuilly but also to attempt to unlock other secrets of Romanesque sculpure by applying this or other elements of contemporary thought processes to the parts of a program.     

Very unusual low latitude whistlers with additional traces of the Earth-ionosphere waveguide propagation effect

The present paper reports very unusual whistlers strongly influenced by the Earth-ionosphere waveguide propagation after emerging from the ionosphere, as observed simultaneosly at our two stations, Sakushima (geomag. lat. 24°) and Kagoshima (20°). These unsual whistlers are characterized by clearly exhibiting additional dispersion effects near the cut-off frequencies of the 1st and 2nd order modes of waveguide propagation and, to our knowledge, they are a new finding. All the subionospheric dispersion is deduced to occur between the ionospheric exit point and the receiver. Detailed spectral analysis, after extracting the small waveguide dispersion effect from the overall spectrum by taking the beat with the appropriate pseudo-whistler, has enabled us to determine the propagation distance of the ionospheric exit region from each station. These distances have then been used to locate the ionospheric exit region, which is found to be about 3000 km east of the stations and in the local sunrise time sector. The generation mechanism of such unusual whistlers is discussed in terms of the joint influences of the ionospheric transmission mechanism (longitudinal gradient of the ionosphere, wave scattering by density irreglarities) and magnetospheric propagation and characteristics of ducts.     

A bayesian approach to wiggle-matching

“Wiggle-matching” is a technique developed to provide calendar dates for a series of samples of known deposition rate using the now well-established high-precision radiocarbon calibration curve. In this paper we describe how the technique may be formulated within the Bayesian framework for statistical analysis and thereby permit the incorporation of uncertainties regarding the deposition rate. The methodology is illustrated by two archaeological examples.     

A Weberian approach to the history of ethics: Aquinas and Kant

A distinction between hard-to-shake but rational convictions, on the one hand, and the rationality that calculates causal and logical consequences, on the other hand, can generate questions for the history of ethics. Most moral thinkers draw some such distinction but the contours of the line differ greatly, and, in drawing the line, past moral thinkers tend to be influenced by their own deeply held principles, which in turn tend to reflect their social world. Questions about where the line between values and instrumental calculation are drawn and about the effect on this of the moral thinkers own social world are applied by way of illustration to Thomas Aquinas and Kant. The paper attempts to use Weberian social theory to elucidate a theme in the history of ethics, making every effort to keep the two kinds of theory distinct.     

A statistical approach to the archaeological identification of crop processing

Since the processing of crops has a direct effect on the composition of archaeobotanical samples, variation due to crop processing must be filtered out before using samples for the study of crop economy and husbandry. As the archaeological context of plant material does not often provide a reliable basis for the identification of crop processing products and byproducts, this paper presents a method based on the statistical comparison of archaeological samples with ethnographically collected material and on an internal statistical analysis of the archaeological samples themselves. These analyses make use of differences in the categories of weed seeds extracted at each stage of the crop processing sequence and are thus more reliable and more widely applicable than simple calculations of the relative quantities of grain, chaff and weed. Ethnographic and archaeological material from Greece is used to illustrate the method and some of the wider implications of the results are discussed.     

Revisiting the structuring effect of transportation infrastructure: An empirical approach with the French railway network from 1860 to 1910

The development of the French railway network was mostly planned in a centralized manner. Despite the multiplication of travel opportunities, the local impact on the demographics is often given as an indirect effect of this spatial transformation. However, this “structuring effect” is still subject to controversies within the academia.

In this paper, we construct a historical geographic information system describing the evolution of the French network. We use it to compute accessibility measures based on network access and travel durations. We first observe that the network growth indeed achieved the various planning goals in terms of functional accessibility. We then present further evidences that the “structuring effect” of the train network on cities demographics is very limited if not null.     

A geographical approach to trust in tourism

Abstract

Within tourism research, trust has largely been conceptualised from psychological perspectives, allowing insights into the mechanisms through which resident/stakeholder relations generate trust. Whilst this work is valuable in understanding dynamics of trust relations, such focus has meant less attention and has been given to the ways space influences trust in tourism contexts. Thus, a geographical approach is put forth to understanding trust in tourism. Through observation and semi-structured interviews concerned with the implementation of a community tourism project in southwest China, insights are provided illustrating how trust is inscribed in place. It is shown that in the Chinese context, cultural place-based specificities relating to pre-existing governance structures, social hierarchies, and the intersection of power, knowledge and trust influence the (in)abilities of NGOs to develop trust with specific residents. More meaningful dialogue between tourism research and geographical conceptualisations of trust is called for – as a way to attend to spatial and scalar differences in understanding of trust within tourism contexts.