Topography Type Research Articles

Inter- and intraobserver reliability of the MTM-classification for proximal humeral fractures: A prospective study

BackgroundA precise modular topographic-morphological (MTM) classification for proximal humeral fractures may address current classification problems. The classification was developed to evaluate whether a very detailed classification exceeding the analysis of fractured parts may be a valuable tool.MethodsThree observers classified plain radiographs of 22 fractures using both a simple version (fracture displacement, number of parts) and an extensive version (individual topographic fracture type and morphology) of the MTM classification. Kappa-statistics were used to determine reliability.ResultsAn acceptable reliability was found for the simple version classifying fracture displacement and fractured main parts. Fair interobserver agreement was found for the extensive version with individual topographic fracture type and morphology.ConclusionAlthough the MTM-classification covers a wide spectrum of fracture types, our results indicate that the precise topographic and morphological description is not delivering reproducible results. Therefore, simplicity in fracture classification may be more useful than extensive approaches, which are not adequately reliable to address current classification problems.

Relationship between trends in temperature extremes and elevation in the eastern and central Tibetan Plateau, 1961–2005

Trend magnitudes of 11 indices of temperature extremes at 71 stations with elevations above 2000 m a.s.l. in the eastern and central Tibetan Plateau (TP) during 1961–2005 are examined. Most trends in extremes are consistent with general warming in the TP. There are no significant correlations between elevation and trend magnitude of temperature extremes with the exception of TXn (coldest day temperature) and TX10 (cold day frequency). Thus an enhanced sensitivity of temperature extremes at higher elevations in the eastern and central TP is not apparent in the context of recent warming in this region. Although previous work showed a correlation between elevation and mean temperature trends in the TP, this analysis fails to substantiate this relationship for extremes. Analysis of trend magnitudes by topographic type and degree of urbanization show both factors to have a strong influence in this dataset, which overrides that of elevation.

White matter tractography by diffusion tensor imaging plays an important role in prognosis estimation of acute lacunar infarctions

The aim of this study was to evaluate the anatomical and clinical relationship between lacunar infarction and the corticospinal tract (CST) in patients with acute lacunar infarction and predict clinical outcome. We examined 28 pyramidal tract stroke patients in the acute phase or early subacute phase (<3 days) with a marked motor deficit. The anatomical location and the extent of CST involvement within the infarcts were visualized on three-dimensional colour-coded diffusion tensor tractography (DTT). With regard to the CST, all patients were divided into three clinical subgroups: Group 1 (intact type), Group 2 (partial involvement type) and Group 3 (whole involvement type). Subsequently, the severity of the motor deficit of each patient was determined according to the National Institutes of Health Stroke Scale (NIHSS) scores at the acute/early subacute phase (<3 days after onset of symptoms), early chronic phase (8-14 days) and outcome (30-60 days). NIHSS scores of Group 1 (12/28) were significantly lower than those of Group 2 (9/28) at the acute phase or early subacute phase (U = -2.816, p<0.01), and those of Group 2 were significantly lower than those of Group 3 (7/28) (U = -3.136, p<0.01). At outcome,NIHSS scores of Group 1 were significantly lower than those of Group 2 (U = -2.846, p<0.01), and scores of Group 2 were significantly lower than those of Group 3 (U = -3.130, p<0.01). At the same time, the NIHSS scores of each group gradually decreased from acute phase to outcome, Neurological improvement was statistically different among the three topographical types of infarction (H = 26.15, p<0.01; H = 11.03, p<0.01; H = 10.05, p<0.01). In conclusion, the three-dimensional colour-coded DTT allows in vivo differentiation of distinct CST stroke subtypes and may help in better establishing the prognosis for patients after CST stroke.

COVARIATES AFFECTING SPATIAL VARIABILITY IN BISON TRAVEL BEHAVIOR IN YELLOWSTONE NATIONAL PARK

Understanding mechanisms influencing the movement paths of animals is essential for comprehending behavior and accurately predicting use of travel corridors. In Yellowstone National Park (USA), the effects of roads and winter road grooming on bison (Bison bison) travel routes and spatial dynamics have been debated for more than a decade. However, no rigorous studies have been conducted on bison spatial movement patterns. We collected 121 380 locations from 14 female bison with GPS collars in central Yellowstone to examine how topography, habitat type, roads, and elevation affected the probability of bison travel year-round. We also conducted daily winter bison road use surveys (2003-2005) to quantify how topography and habitat type influenced spatial variability in the amount of bison road travel. Using model comparison techniques, we found the probability of bison travel and spatial distribution of travel locations were affected by multiple topographic and habitat type attributes including slope, landscape roughness, habitat type, elevation, and distances to streams, foraging areas, forested habitats, and roads. Streams were the most influential natural landscape feature affecting bison travel, and results suggest the bison travel network throughout central Yellowstone is spatially defined largely by the presence of streams that connect foraging areas. Also, the probability of bison travel was higher in regions of variable topography that constrain movements, such as in canyons. Pronounced travel corridors existed both in close association with roads and distant from any roads, and results indicate that roads may facilitate bison travel in certain areas. However, our findings suggest that many road segments used as travel corridors are overlaid upon natural travel pathways because road segments receiving high amounts of bison travel had similar landscape features as natural travel corridors. We suggest that most spatial patterns in bison road travel are a manifestation of general spatial travel trends. Our research offers novel insights into bison spatial dynamics and provides conceptual and analytical frameworks for examining movement patterns of other species.

Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature

An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria–slope gradient, local convexity, and surface texture–are calculated from a square-grid digital elevation model (DEM). The sequence of programmed operations combines twofold-partitioned maps of the three variables converted to greyscale images, using the mean of each variable as the dividing threshold. To subdivide increasingly subtle topography, grid cells sloping at less than mean gradient of the input DEM are classified by designating mean values of successively lower-sloping subsets of the study area (nested means) as taxonomic thresholds, thereby increasing the number of output categories from the minimum 8 to 12 or 16. Program output is exemplified by 16 topographic types for the world at 1-km spatial resolution (SRTM30 data), the Japanese Islands at 270 m, and part of Hokkaido at 55 m. Because the procedure is unsupervised and reflects frequency distributions of the input variables rather than pre-set criteria, the resulting classes are undefined and must be calibrated empirically by subsequent analysis. Maps of the example classifications reflect physiographic regions, geological structure, and landform as well as slope materials and processes; fine-textured terrain categories tend to correlate with erosional topography or older surfaces, coarse-textured classes with areas of little dissection. In Japan the resulting classes approximate landform types mapped from airphoto analysis, while in the Americas they create map patterns resembling Hammond's terrain types or surface-form classes; SRTM30 output for the United States compares favorably with Fenneman's physical divisions. Experiments are suggested for further developing the method; the Arc/Info AML and the map of terrain classes for the world are available as online downloads.

Influence of equinus treatments on the vertical displacement of the body's centre of mass in children with cerebral palsy

We assessed the influence of equinus gait treatments on the vertical displacement of the body's centre of mass (COM) in 21 patients with cerebral palsy (14 males, 7 females; mean age 8 y 9 mo [SD 2 y]; range 3 y 7 mo-17 y) presenting different topographical types (quadriplegia, n = 1; diplegia, n = 6; right hemiplegia, n = 6; and left hemiplegia, n = 8). Vertical COM displacement was computed from ground reaction forces, and lower limb kinematics was recorded simultaneously. Equinus gait was treated with non-operative treatments (i.e. botulinum toxin injections and stretching casts) in 14 patients, and with operative treatments in seven patients. After non-operative treatments, the entire ankle displacement shifted towards dorsiflexion throughout the gait cycle, but the amplitude of the third foot rocker (TR) and vertical COM displacement remained unchanged. However, after operative treatments, the amplitude of TR increased and vertical COM displacement decreased. A negative linear correlation was found between the former variables in all the patients where 53% of the changes in their vertical COM displacement, after equinus gait treatments, were explained by the changes in TR amplitude. In fact, TR remains a main gait determinant, reducing the vertical COM displacement after equinus gait treatment and influencing the general gait pattern.

Effects of jpeg 2000 compression on automated dsm extraction: evidence from aerial photographs

AbstractThis paper evaluates the effects of JPEG 2000 compression on automated digital surface model (DSM) extraction, using the area‐based matching technique. Two stereopairs of aerial photographs, which have different photo scale, pixel size, and topographic type, are used as the images for the experiments. In the experiments, the DSM generated from the uncompressed image is set as the reference, and the elevation accuracy is computed for a range of compression ratios (2:1 to 100:1). The results show that the employed indices of image quality based on the JPEG 2000 compression are clearly superior to the commonly used JPEG compression technique—especially for high compression ratios. However, the elevation accuracy varies with the compression ratios. Also, JPEG 2000 compression does not have a significant influence on the percentage of the successful matching rate. In addition, a near linear fall‐off is observed in extracted DSM accuracy with increasing compression ratios.

Species composition and assemblage structure of chironomid larvae (Diptera: Chironomidae) attaching to the artificial substrates in a Japanese temperate basin, in relation to the longitudinal gradient

The relative importance of natural and anthropogenic factors, especially topographic type, riparian canopy, altitude, temperature and bank protection, on larval chironomid assemblage was investigated in a Japanese basin. To focus on the macro-scale factors, a concrete block, as an artificial substrate, was used for chironomid collection so that sampling regime may be identical among the sites. Partial CCA using sampling month as a covariable revealed that topographic type, riparian canopy coverage, water temperature and altitude were the main factors influencing species distribution. Stempellinella tamaseptima, Polypedilum tamanigrum and five Rheotanytarsus species showed positive, whereas five Cricotopus species showed negative associations with canopy coverage. Some traditional longitudinal zonations of species were still shown. Chironomus flaviplumus and Chironomus yoshimatsui were merely associated with lower reaches. Stepwise multiple regressions of the assemblage indices on the environmental variables were applied. Bank protection and depth showed negative correlations with Shannon diversity H′. Both topographic type and depth showed negative correlations with Pielou equitability J. Topographic type (lower reach) and specific conductance showed positive, while bank protection showed a negative correlation with abundance. Species richness was not explained by any variables. As a whole, topographic type was the most directly related factor to chironomid assemblages.

Landslide susceptibility mapping using GIS and the weight-of-evidence model

The weights-of-evidence model (a Bayesian probability model) was applied to the task of evaluating landslide susceptibility using GIS. Using landslide location and a spatial database containing information such as topography, soil, forest, geology, land cover and lineament, the weights-of-evidence model was applied to calculate each relevant factor's rating for the Boun area in Korea, which had suffered substantial landslide damage following heavy rain in 1998. In the topographic database, the factors were slope, aspect and curvature; in the soil database, they were soil texture, soil material, soil drainage, soil effective thickness and topographic type; in the forest map, they were forest type, timber diameter, timber age and forest density; lithology was derived from the geological database; land-use information came from Landsat TM satellite imagery; and lineament data from IRS satellite imagery. Tests of conditional independence were performed for the selection of factors, allowing 43 combinations of factors to be analysed. For the analysis of mapping landslide susceptibility, the contrast values, W + and W -, of each factor's rating were overlaid spatially. The results of the analysis were validated using the previous landslide locations. The combination of slope, curvature, topography, timber diameter, geology and lineament showed the best results. The results can be used for hazard prevention and land-use planning.

Influence of gait pattern on the body's centre of mass displacement in children with cerebral palsy.

We assessed the influence of digitigrade gait pattern, topographical types, severity of motor involvement, and locomotor experience on the body's centre of mass (COM) displacement during gait in children with spastic cerebral palsy (CP). Three-dimensional COM displacements were computed from ground reaction forces in 51 independent digitigrade walkers (29 males, 22 females; mean age 10 years 6 months, SD 2 years 7 months, range 7 to 15 years). Results obtained from 10 participants without disabilities (five males, five females), in the same age range as the patients with CP, were used as a reference plantigrade group. Vertical and forward COM displacements were significantly different between the digitigrade and the plantigrade walkers. Neither the topographical type (quadriplegia, n=5; diplegia, n=20; right hemiplegia, n=13; left hemiplegia, n=13), nor the severity of motor involvement, nor the locomotor experience influenced COM displacements. We conclude that the COM displacement during gait in patients with CP was mainly influenced by the digitigrade gait pattern encountered in this neurological disorder rather than the different topographical types and motor involvements.

Influence of gait pattern on the body's centre of mass displacement in children with cerebral palsy

We assessed the influence of digitigrade gait pattern, topographical types, severity of motor involvement, and locomotor experience on the body's centre of mass (COM) displacement during gait in children with spastic cerebral palsy (CP). Three‐dimensional COM displacements were computed from ground reaction forces in 51 independent digitigrade walkers (29 males, 22 females; mean age 10 years 6 months, SD 2 years 7 months, range 7 to 15 years). Results obtained from 10 participants without disabilities (five males, five females), in the same age range as the patients with CP, were used as a reference plantigrade group. Vertical and forward COM displacements were significantly different between the digitigrade and the plantigrade walkers. Neither the topographical type (quadriplegia, n=5; diplegia, n=20; right hemiplegia, n=13; left hemiplegia, n=13), nor the severity of motor involvement, nor the locomotor experience influenced COM displacements. We conclude that the COM displacement during gait in patients with CP was mainly influenced by the digitigrade gait pattern encountered in this neurological disorder rather than the different topographical types and motor involvements.

Habitat use and conservation status of two elusive ground birds (Carpococcyx radiatus and Polyplectron schleiermacheri) in the Sungai Wain Protection Forest, East Kalimantan, Indonesian Borneo

We studied the distribution and habitat-use of two endemic ground birds, the Bornean ground-cuckoo Carpococcyx radiatus and the Bornean peacock-pheasant Polyplectron schleiermacheri in the Sungai Wain Protection Forest, East Kalimantan. Both species are highly elusive and neither has been subject to any in-depth study. Consequently, few data are available on their population numbers, habitat preferences and conservation status. We mapped the species' presence in five topographical habitat types, assessed their spatial distribution, and provide an estimate of population sizes in the reserve. Over a period of 44 months (1997–2003) we had 32 encounters with Bornean ground-cuckoo, and 19 encounters with Bornean peacock-pheasant. Number of encounters increased over time, but no seasonal or monthly difference was apparent in encounter rate. Both species were only observed inside the central core of the reserve. Bornean ground-cuckoo showed a clear preference for alluvial and swamp forest over high-flat, slope and ridge forest. Bornean peacock-pheasant showed no clear preference for any of these five habitat types. Considering the rapid destruction of forest occurring in Kalimantan due to illegal logging, fires, lack of law enforcement and proper management of protected areas, the conservation of these two species is discussed in relation to conservation management of the Sungai Wain Protection Forest. Teams are patrolling year-round in the reserve to halt hunting. Illegal logging has been eradicated by these patrols, in combination with tree-spiking. Fire breaks are maintained each dry season to avoid further fire damage, and extensive education and awareness work is carried out in the district.

Effects of topographic heterogeneity on tree species richness and stand dynamics in a subtropical forest in Okinawa Island, southern Japan

Summary 1 We used a structural equation model (SEM) to clarify the relationship between productivity and species richness across a topographic gradient in a subtropical forest in southern Japan and to quantify the direct and indirect effects of topographic position and soil properties on community attributes. 2 Higher soil nitrogen on ridges was associated with low soil pH and high soil organic matter, but differences in soil chemistry were small compared with those observed in tropical forests. 3 Species richness increased from the valley, via slopes, to ridges. Understorey and microphyllous species, both of which are typically found in gaps or in windy sites, were more abundant on slopes and ridges than in the valley. Habitat preferences of the species, reflecting shade/drought tolerance rather than soil fertility, may be a primary cause of differences in species richness between the topographic types. 4 The total effect of species richness on biomass increment was greater than that of tree density, and biomass increment increased linearly with species richness. This, together with the fact that combined effects of topography, soil properties and ground flora on biomass increment were comparable with that of tree density, indicates that the relationship was caused by habitat heterogeneity rather than a density effect. 5 Frequent disturbances and chronic wind stress resulted in higher mortality and a greater loss of biomass, especially on the ridges, and probably prevented species with different functional traits (e.g. maximum height) from competing for light. 6 Topographic variation therefore appears to lead to structural/compositional heterogeneity within this subtropical forest, enabling the occurrence of a wider range of species. The growth and survival of a variety of species with different functional traits are diversified by environmental conditions along the topographic position. This causes variation in productivity between the topographic types, and suggests that functional resilience associated with species richness contributes to high productivity.

Eco-environment range in the source regions of the Yangtze and Yellow rivers

Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper. According to the comprehensive analysis of topographical characteristics, climate conditions, vegetation distribution and hydrological features, the source region ranges for eco-environmental study are defined. The eastern boundary point is Dari hydrological station in the upper reach of the Yellow River. The watershed above Dari hydrological station is the source region of the Yellow River which drains an area of 4.49 x 104 km2. Natural environment is characterized by the major topographical types of plateau lakes and marshland, gentle landforms, alpine cold semi-arid climate, and steppe and meadow vegetation in the source region of the Yellow River. The eastern boundary point is the convergent site of the Nieqiaqu and the Tongtian River in the upstream of the Yangtze River. The watershed above the convergent site is the source region of the Yangtze River, with a watershed area of 12.24 x104 km2. Hills and alpine plain topography, gentle terrain, alpine cold arid and semi-arid climate, and alpine cold grassland and meadow are natural conditions in the source region of the Yangtze River.

Suppression of debris movement by forests and damage to forests by debris deposition

Forest buffer zones have recently been introduced in an attempt to suppress debris movement caused by mass wasting. There are, however, many questions left unsolved regarding the role of forests in suppressing debris movement and damage to forests by debris deposition. A number of debris avalanches occurred in southern Fukushima Prefecture and Hiroshima Prefecture in August 1998 and June 1999, respectively. Suppression of debris movement by forests and damage to forests by debris deposition were investigated in this study using aerial photographic interpretation and topographic analysis. Of the debris avalanches delineated in the Fukushima and Hiroshima areas, 282 and 84 sites, respectively, were forested, and 43 and seven sites, respectively, were nonforested. Topographic parameters, land use, and forest type at each site were surveyed by aerial photographic interpretation and topographic analysis. Suppression of debris movement by forest vegetation was confirmed by higher equivalent coefficients of friction and shorter average deposition zone length (about 28% and 55% shorter in the Fukushima and Hiroshima areas, respectively) in forested sites compared with nonforested sites. While previous studies suggested that the width of the forest zone required to prevent sediment outflow by surface erosion increases with increasing slope gradient, no clear relationship was found in this study. While the length of deposition zone of debris material (this study) is strongly affected by the dynamic solid friction coefficient and fluid friction of debris material, the length of deposition zone of the outflow of surface wash (past studies) is mainly affected by the tractive force of water flow. Among the 65 trees that remained at the terminus of deposition zones at five sites, 36 were alive and 29 were dead. Damage to the forest increases with increasing thickness of deposits and decreases with increasing tree diameter. Such results are useful for designing forest buffer zones.

Carbon budget of coral reef systems: an overview of observations in fringing reefs, barrier reefs and atolls in the Indo-Pacific regions

The seawater CO2 system and carbon budget were examined in coral reefs of wide variety with respect to topographic types and oceanographic settings in the Indo-Pacific oceans. A system-level net organic-to-inorganic carbon production ratio (ROI) is a master parameter for controlling the carbon cycle in coral reef systems, including their sink/source behavior for atmospheric CO2. A reef system with ROI less than approximately 0.6 has a potential for releasing CO2. The production ratio, however, is not easy to estimate on a particular reef. Instead, observations planned to detect the offshore—lagoon difference in partial pressure of CO2 (p CO2) and a graphic approach based on a total alkalinity—dissolved inorganic carbon diagram can reveal system-level performance of the carbon cycle in coral reefs. Surface pCO2 values in the lagoons of atolls and barrier reefs were consistently higher than those in their offshore waters, showing differences between 6 and 46 µatm, together with a depletion in total alkalinity up to 100 µmol kg−1, indicating predominant carbonate production relative to net organic carbon production. Reef topography, especially residence time of lagoon water, has a secondary effect on the magnitude of the offshore—lagoon pCO2 difference. Terrestrial influence was recognized in costal reefs, including the GBR lagoon and a fringing reef of the Ryukyu Islands. High carbon input appears to enhance CO2 efflux to the atmosphere because of their high dissolved C:P ratios. Coral reefs, in general, act as an alkalinity sink and a potentially CO2-releasing site due to carbonate precipitation and land-derived carbon.

A COMPLETE SYSTEM FOR INTERPRETATION OF COLOR MAPS

The paper describes a system and technology for the automatic/interactive interpretation of color maps. Due to the fact that a completely automatic solution is impossible, a combination of automatic and interactive techniques is used. Firstly, color recognition and separation is performed. For automatic map vectorization, a special fast scheme is used. To make digitization more automatic and user-friendly, an interactive digitizing mode has been developed to extract line-based cartographic objects from vectorised data. The system has a powerful and friendly user interface that is described in the paper. The system is used successfully in the digitization of topographic and other types of map.

Modelling the species richness distribution of French dung beetles (Coleoptera, Scarabaeidae) and delimiting the predictive capacity of different groups of explanatory variables

AbstractAim To predict French Scarabaeidae dung beetle species richness distribution, and to determine the possible underlying causal factors.Location The entire French territory has been studied by dividing it into 301 grid cells of 0.72 × 0.36 degrees.Method Species richness distribution was predicted using generalized linear models to relate the number of species with spatial, topographic and climate variables in grid squares previously identified as well sampled (n = 66). The predictive function includes the curvilinear relationship between variables, interaction terms and the significant third‐degree polynomial terms of latitude and longitude. The final model was validated by a jack‐knife procedure. The underlying causal factors were investigated by partial regression analysis, decomposing the variation in species richness among spatial, topographic and climate type variables.Results The final model accounts for 86.2% of total deviance, with a mean jack‐knife predictive error of 17.7%. The species richness map obtained highlights the Mediterranean as the region richest in species, and the less well‐explored south‐western region as also being species‐rich. The largest fraction of variability (38%) in the number of species is accounted for by the combined effect of the three groups of explanatory variables. The spatially structured climate component explains 21% of variation, while the pure climate and pure spatial components explain 14% and 11%, respectively. The effect of topography was negligible.Conclusions Delimiting the adequately inventoried areas and elaborating forecasting models using simple environmental variables can rapidly produce an estimate of the species richness distribution. Scarabaeidae species richness distribution seems to be mainly influenced by temperature. Minimum mean temperature is the most influential variable on a local scale, while maximum and mean temperature are the most important spatially structured variables. We suggest that species richness variation is mainly conditioned by the failure of many species to go beyond determined temperature range limits.

Correlation between physical functioning and gait measures in children with cerebral palsy

The primary aim of this investigation was to assess the correlation between the POSNA Musculoskeletal Functional Health Questionnaire (POSNA) and gait analysis in children with cerebral palsy (CP). POSNA and computerized gait analysis were used to evaluate individuals with CP. Correlations were investigated between POSNA scales, gait parameters, and the Gillette Functional Assessment Questionnaire (FAQ) in 63 children (31 males, 32 females; mean age 9.17 years [SD 3.06], age range 3.75 to 16.44 years) with spastic CP. Twelve participants had hemiplegia, 29 diplegia, 12 quadriplegia, and 10 triplegia. The result of backwards stepwise multiple regression analysis indicated that the Log normalcy index (NI) was a significant predictor of the POSNA Global Function and Comfort scale. Energy expenditure (EE) did not add significantly to the prediction. The POSNA scales differentiated between the different topographical types of CP. The POSNA scale is a valid and useful clinical measure. Used in conjunction with the NI, EE, and FAQ, the POSNA scale provides a more complete appraisal of change in functioning.

Higher-order chromatin structure of human granulocytes.

The structural organisation of chromatin in eukaryotes plays an important role in a number of biological processes. Our results provide a comprehensive insight into the nuclear topography of human peripheral blood granulocytes, mainly neutrophils. The nuclei of granulocytes are characterised by a segmented shape consisting of two to five lobes that are in many cases connected by a thin DNA-containing filament. The segregation of chromosomes into the nuclear lobes was studied using fluorescence in situ hybridisation (FISH). We were able to distinguish different topographic types of granulocytes on the basis of the pattern of segregation. Five topographic types were detected using dual-colour FISH in two-lobed nuclei. The segregation of four sets of genetic structures could be studied with the aid of repeated FISH and a large number of topographic types were observed. In all these experiments a non-random distribution of chromosomes into nuclear lobes was found. The painting of a single type of chromosome in two-lobed nuclei showed the prevalence of symmetric topographic types (on average in 65.5% of cases) with significant variations among individual chromosomes. The results of analysis of five topographic types (defined by two chromosomes in two-lobed nuclei) showed that the symmetric topographic types for both chromosomes are significantly more frequent than predicted. Repeated hybridisation experiments confirmed that the occurrence of certain patterns of chromosome segregation is much higher than that predicted from the combination of probabilities. The frequency of symmetric topographic types for chromosome domains was systematically higher than for genes located on these chromosomes. It appears that the prevalence of symmetric segregation patterns is more probable for large objects such as chromosome domains than for genes located on chromatin loops extending outwards from the surface of the domain defined by specific chromosome paints. This means that one chromosome domain may occur in different lobes of granulocytic nuclei. This observation is supported by the fact that both genes and centromeres were observed on filaments joining different lobes. For all chromosomes, the distances between the membrane and fluorescence gravity centre of the chromosome were measured and correlated with the segregation patterns. A higher percentage of symmetric topographic types was found in those chromosomes that were located closer to the nuclear membrane. Nuclear positioning of all genetic elements in granulocytic nuclei was studied in two-dimensional projection; however, the results were verified using three-dimensional analysis.