Map Registration Research Articles

The Critical Period for Experience-dependent Plasticity in a System of Binocular Visual Connections in Xenopus laevis: Its Temporal Profile and Relation to Normal Developmental Requirements.

A commissural system of 'intertectal' connections in Xenopus mediates the registration of binocular visual maps at the midbrain optic tectum. Following surgical eye rotation in larval animals, the system can completely alter its pattern of connectivity to restore binocular visual registration at the tectum. This experimentally induced plasticity is known to require visual experience and thought to be subject to an age-related restriction: eye rotation in adult animals is reported to provoke no subsequent intertectal alteration. In this paper we describe the detailed age-dependence of this plasticity. One eye was rotated in 238 animals of various developmental stages between mid-larval and adult life. At each age, different animals received rotations of different sizes, ranging from 20 to 180 degrees. The pattern of intertectal connectivity was mapped electrophysiologically 1 - 2 years postoperatively. A 'critical' period was defined around the time of metamorphosis: the vast majority of animals receiving a rotation in larval life (up to approximately 2 weeks before metamorphic climax) showed altered intertectal connections, whereas none of the animals operated upon at 3 months or more postmetamorphosis displayed the plasticity. At intervening ages, altered intertectal connections were found only in response to progressively smaller eye rotations. The profile of this critical period was further shown to mirror temporal features of the changes in eye position that occur in Xenopus as natural consequences of head growth, and which themselves impose a normal developmental requirement for intertectal plasticity. We conclude that the capacity of the Xenopus intertectal system for plasticity in response to abnormal experience undergoes a progressive age-dependent decline, and that the profile of this decline is delimited by normal requirements.

The Critical Period for Experience-dependent Plasticity in a System of Binocular Visual Connections in Xenopus laevis: Its Extension by Dark-rearing.

Following surgical rotation of an eye, the Xenopus 'intertectal' system is capable of a vision-dependent alteration of its connectivity, that restores spatial registration of binocular maps on the optic tectum. In the preceding paper (Keating and Grant, Eur. J. Neurosci., 4, 27 - 36, 1992), we reported that this capacity undergoes a progressive, age-dependent restriction during a critical period around the time of metamorphosis, so that rotations produced in animals aged >/=3 months postmetamorphosis normally evoke no such alteration of the system. Here we examine whether this restriction is rigidly age-dependent or whether vision can influence its profile. We report that in animals dark-reared from embryonic stage 35 through the critical period to 3 months, 1 year or even 2 years after metamorphosis, rotations instituted at those ages now result in intertectal reorganization if a period of normal vision is allowed after the operation. Similarly, intertectal alteration was also seen in animals eye-rotated at larval stage 58, then dark-reared just for the duration of the critical period, and subsequently returned, at 3 months of age, to a normal visual environment. We conclude, therefore, that the normal developmental restriction in the plasticity of the Xenopus intertectal system is not strictly age-dependent, but that vision contributes to the process by activating the underlying plasticity mechanisms.

Latency and temporal overlap of visually elicited contralateral and ipsilateral firing in Xenopus tectum during and after the critical period

The mechanisms underlying the development of proper topographic registration of binocular maps in the tectum of Xenopus laevis involve correlation of activity patterns of ipsilateral and contralateral inputs. Recent evidence implicates NMDA-type glutamate receptors in this process. In general, NMDA receptors are considered to function optimally when there are multiple, simultaneous excitatory inputs to a dendrite. In the binocular system of the frog, however, the ipsilateral eye's response to a visual stimulus reaches the tectum later than the contralateral eye's response. The reason for this delay is that the ipsilateral pathway to the tectum is indirect, involving a relay in the opposite tectum and nucleus isthmi. In this paper, we evaluate the duration of the delay between arrival of contralateral and ipsilateral input in response to cessation of light and we also gauge the extent of temporal overlap in responses of the two inputs. We find that the average delay is about 10 ms and that this delay is not significantly different during the critical period vs later in development. The temporal overlap is 40–60 ms in duration. We conclude that the intertectal delay does not prevent a substantial period of simultaneous firing of ipsilateral and contralateral inputs in response to sudden changes in illumination. Therefore, the firing patterns of these afferents are compatible with a mechanism of activity-dependent alignment of binocular maps in the tectum.

Tropical Epidemiology: A System for Continuous Demographic Monitoring of a Study Population

Epidemiologists in many developing countries, where official demographic services are unavailable, have to include some demographic functions in their work. The usual method of documenting a study population for epidemiological research in a developing country consists of three stages: mapping, enumeration and vital registration. This paper considers the last element of this process, detailing the development of a suitable data system and explaining how its implementation using microcomputers and a database management system can help in the creation of an on-line continuous vital registration system for a study population as an epidemiological tool. The issues covered are data collection, entry and analysis, and the advantages of such a system for use in epidemiological research in developing countries are also discussed.

GROUND CONTROL DETERMINATION FOR REGISTRATION OF SATELLITE IMAGERY USING DIGITAL MAP DATA

AbstractWork is reported on the production of terrain elevation data from SPOT imagery. An important step in this process is determination of exterior orientation parameters for the images. Although an initial estimate is available in the SPOT header, refinements are required based on plan and height data. These are generally derived from photogrammetric measurements (or sources such as global positioning satellite systems), but accurate manual determination is time consuming.This paper reports an alternative approach by investigating the use of existing map data (located on the earth's surface and in a known projection) to find corresponding “ground control points” in both map and image. Available maps may be in digital or paper form depending on the state of development of mapping in the part of the world being studied. The last revision date and the cartographic generalisation employed will also effect the fidelity of the final result. Practical semi‐automatic techniques for determining the height of ground control points from existing map data are described, including multiple profiles through digitised contour data, a commercial terrain modelling package based on Delaunay triangulation and the use of triangulation points on prominent features.Comparisons between the methods are made and results obtained are compared with Institut Géographique National datasets and photogrammetric measurements. Methods for fully automating not only the height determination but also the location of ground control features within a map database are discussed. Map and image registration is described and illustrated using Laser‐Scan's Rover software. Interactive and automated methods of registration are discussed.

CADASTRAL MAPPING FOR DEVELOPMENT IN CENTRAL AMERICA AND THE CARIBBEAN 1960–1980

Cadastral mapping and land registration activities in Central America and the Caribbean between 1960 and 1980 are examined in this study. It evaluates them as development tools, focusing particularly on their contribution towards the improvement of property tax systems. In most cases, the countries studied sucessfully executed the cadastral mapping and land registration projects they embarked upon, although lengthy delays in execution occurred frequently. While technically successful, the projects commonly were ineffective in realizing improvements in the property tax system because of subsequent political and administrative decisions. Policy makers and mapping scientists involved in the planning of cadasters in developing countries should evaluate realistically the time required for their execution, the degree of planimetric accuracy needed, and their immediate potential for contributing to the development process prior to the initiation of a cadaster.

地震被害原因調査における古地図特に明治地籍図の利用

Earthquake damage is usually related to ground conditions, which is determined by the history of the area. Old maps can be important in revealing the ground history. Land register maps (1/600 scale) from the early Meiji age can provide important information on the ground condition of Japan in the 1880's.Successful use of the maps is demonstrated with an application to the disaster at Matsumi-machi, Araya, Akita, which suffered from severe damage due to liquefaction of sandy ground in the Nihonkai-chubu Earthquake, May 26, 1983. The damage was almost completely limited to a narrow area (about 30m×100m) of nearly flat ground recently made by leveling the long bank of a rifle range constructed by the Japanese army in 1897. The ground condition before constructing the bank could not be known from any other available maps and information. Land register maps revealed that the damaged area was land reclaimed from a pond. Comments on the maps extend usefulness of the maps which differ from the usual topographic maps.

The role of the Cadastre in a statewide land information system

Abstract This paper examines the relationship of the three major components in any cadastral system, namely land registration, cadastral surveying and large-scale cadastral mapping, to a statewide parcel-based land information system. Particular emphasis is given to New South Wales, although many of the comments have application to similar cadastral systems in Australia and overseas.

明治前期の地籍図

明治前期の地籍図

The assessment of a Swiss cadastre from an Australian perspective

Abstract As an aid to understanding the application of the concept of multi-purpose cadastres in Australia, a true fully-operational multi-purpose cadastre has been described—the cadastre chosen is that of the Canton de Vaud in Switzerland. In particular the relationship between title registration, cadastral surveying and large scale mapping is discussed. Those aspects of the cadastral system which have relevance to the Australian situation are highlighled and assessed.

Geometric Correction, Registration, and Resampling of Landsat Imagery

SUMMARYThe geometric distortions introduced by the LANDSAT imaging system are well known. However, the satellite does not provide attitude information with sufficient accuracy to determine the geographical position of each picture element or pixel. Thus, to map the data onto the desired space it is necessary to model a geometric transformation from a set of ground control points. Transformation of a LANDSAT image to a UTM co-ordinate grid to 50 metres accuracy (rms) under optimum conditions has been demonstrated. The main factor limiting the ultimate accuracy of the corrected image is the precision to which ground control points on the UTM maps can be mapped to pixels in the LANDSAT image. Digital correlation methods have been used successfully in image-to-image registration to improve the accuracy by 25%, but for map registration, this requires accurately located ground control photographic chips.Various resampling techniques including sin (Πx)/Πx expansions, cubic splines, and Lagrange polynomials are d...

A Historical Geography of the Regional Centres in the Ancient Tohoku Frontier District

About the middle of the 7th century the Tohoku district attracted attention of ancient states under the System of Ritsuryo for their northern frontiers. Shiro or Saku (ancient castle) of both Mutsu and Dewa Kunis (ancient prefectures) were administrative centres as well as frontier forts in the northern borderland. In addition to these were there stationed Gundan, a purely military position and Gunke (Kohri-no-Miyake), an administrative centre of Kohri (ancient county), substructure to Kuni. It is supposed that to these regional establishments are practised gridded urban planning similar to those of Teito (ancient megalopolis) and Kokufu (ancient local capitals).The authors did researches on the urban planning of the ancient regional centres by following the methods of historical geography, comparing with their micro-topography and the present landscapes, examining Koaza (the smallest place name) on the land register maps. The objectives examined were Akita Jyo, Tamatsukuri Gundan, Mutsu-no-Kuni Shimeha-Gunke, Dewa-no-Kuni Murayama-Gunke, and so forth. The results show that there were the gridded plans as in Taga Jyo, Izawa Jyo, and Kinowa-no-Sake, reported already.Secondly, the authors investigated in what location those regional centres were situated in the view point of ancient topography and communication. Especially in respect to the way connecting Taga Jyo with Akita Jyo, we considered its probable route, by making field survey near the Sarubane Toge (pass), and examining its topographical position and attempting to identify the Sarubane Eki (stage).At the same time we investigated the Gridded Pattern, the land so-called Jori form practised under the System of Ritsuryo, near and around these regional centres mentioned above, its forms, areas and limit of distribution. Consequently, we can report such newly found areas with remains of the gridded land pattern as in the valleys of Naruse and Hazama rivers, and observe that allotted lands in each Tsubo, in general, adopt a peculiar form. As to the northern limit of its distribution the line is supposed to be drawn from Morioka to the Akita plain.To the north of the area distributing ancient castle and the gridded land pattern, there was located Noshiro-no-Tamuro, the northernmost fort of the Ritsuryo states. It is considered to be located on the plateau to the south of the Yoneshiro river.