Topographic Distance Research Articles

Multi-omics analysis unveils the predictive value of IGF2BP3/SPHK1 signaling in cancer stem cells for prognosis and immunotherapeutic response in muscle-invasive bladder cancer

BackgroundMuscle invasive bladder cancer (MIBC) is a life-threatening malignant tumor characterized by high metastasis rates, poor prognosis, and limited treatment options. Immune checkpoint inhibitors (ICIs) targeting PD-1 and PD-L1 represent an emerging treatment for MIBC immunotherapy. However, the characteristics of patients likely to benefit from immunotherapy remain unclear.MethodsWe performed single-cell mass cytometry (CyTOF) analysis of 179,483 single cells to characterize potential immunotherapy-related cancer stem cells (CSCs)-like populations in the tumor microenvironment of 38 MIBC tissues. The upregulated expression of IGF2BP3 in CD274 + ALDH + CSC-like cells, which was associated with poor clinical prognosis, was analyzed by bulk RNA-sequencing data from an in-house cohort. The functional role of IGF2BP3 was determined through cell proliferation, colony formation, cell apoptosis and sphere formation assays. The regulation of SPHK1 expression by IGF2BP3 was investigated using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and bulk RNA-sequencing (bulk RNA-seq). We further utilized single-nucleus RNA sequencing (snRNA-seq) data from 67,988 cells of 25 MIBC tissues and single-cell RNA sequencing (scRNA-seq) data from MIBC patient-derived organoids to characterize the molecular features of bladder cancer cells co-expressing IGF2BP3 and SPHK1. Spatial transcriptomics (ST) and co-detection by indexing (CODEX) analysis were used to describe the spatial distribution and interactions of IGF2BP3 + SPHK1 + bladder cancer cells and immune cells.ResultsA subset of CD274 + ALDH + CSC-like cells was identified, associating with immunosuppression and low survival rates in MIBC patients. IGF2BP3, an m6A reader gene, was found to be upregulated in the CD274 + ALDH + CSC-like cell population and linked to poor clinical prognosis in MIBC. Knockout of IGF2BP3 dramatically promoted cell apoptosis and reduced cell proliferation in T24 cells. By integrating MeRIP-seq and bulk RNA-seq analyses, we identified SPHK1 served as a substrate for IGF2BP3 in an m6A-dependent manner. Further snRNA-seq, scRNA-seq, ST, and CODEX analysis revealed a closer topographical distance between IGF2BP3 + SPHK1 + bladder cancer cells and exhausted CD8 + T cells, providing one explanation for the superior response to immunotherapy in IGF2BP3 + SPHK1 + bladder cancer cells-enriched patients. Finally, an ICI-associated signature was developed based on the enriched genes of IGF2BP3 + SPHK1 + bladder cancer cells, and its potential ability to predict the response to immunotherapy was validated in two independent immunotherapy cohort.ConclusionsOur study highlighted the critical involvement of the IGF2BP3/SPHK1 signaling in maintaining the stemness of CSCs and promoting MIBC progression. Additionally, these findings suggested that the IGF2BP3/SPHK1 signaling might serve as a biomarker for prognosis and immunotherapy response in MIBC.

Geographic patterns and environmental correlates of taxonomic, phylogenetic and functional β-diversity of wetland plants in the Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau (QTP) harbours the largest wetland complex in China, with a relatively high diversity of wetland plants. While there has been extensive research on the α-diversity of various plant groups in the QTP, the study of β-diversity specifically in wetland plants has been limited. In this study, we quantified the geographic pattern of wetland plant β-diversity from three dimensions: taxonomic, phylogenetic, and functional. We assessed the relative importance of geographic distance, climatic distance, environmental distance and topographic distance on the pattern of β-diversity. The results indicate a high consistency in the geographic pattern of wetland plant β-diversity across the three dimensions. β-diversity is high in the mountainous regions at the edge of the plateau and relatively low in the plateau platform. The turnover component contributes more to taxonomic β-diversity than nestedness, whereas the opposite is true for phylogenetic and functional β-diversity. Furthermore, taxonomic β-diversity is higher than phylogenetic and functional β-diversity. The geographic patterns of taxonomic, phylogenetic and functional diversity of wetland plants in the QTP are jointly influenced by environmental filtering and dispersal limitation. Climatic variables (temperature seasonality, annual precipitation, precipitation seasonality and annual mean temperature) and topographic variables (elevation variation coefficient, elevation and slope) were identified as the main factors influencing wetland plant β-diversity in the QTP. Overall, this study contributes to elucidating the evolutionary history and formation mechanisms of wetland plant communities in the QTP, and reveals the large-scale patterns of wetland plant diversity.

Euclide, the crow, the wolf and the pedestrian: distance metrics for linguistic typology

It is common for people working on linguistic geography, language contact and typology to make use of some type of distance metric between lects. However, most work so far has either used Euclidean distances, or geodesic distance, both of which do not represent the real separation between communities very accurately. This paper presents two datasets: one on walking distances and one on topographic distances between over 8700 lects across all macro-areas. We calculated walking distances using Open Street Maps data, and topographic distances using digital elevation data. We evaluate these distances. We evaluate these distance metrics on three case studies and show that topographic distance tends to outperform the other distance metrics, but geodesic distances can be used as an adequate approximation in some cases.

Plant diversity patterns along an elevation gradient: the relative impact of environmental and spatial variation on plant diversity and assembly in arid and semi-arid regions

The spatial distribution pattern of species diversity and its driving variables are essential to understanding how biodiversity will respond to the threat of future climatic instability. This study examines how the alpha and beta diversity indices vary along the elevation gradient and which factors are more responsible for arid and semi-arid plant diversity and community assembly. There were 121 species from 90 genera and 42 families found at elevations ranging from 1,200 to 2,600 m within the Ningxia Helan Mountain National Nature Reserve in China. These were primarily shrubs and herbs with characteristics adapted to extreme temperatures. The diversity of both the shrub layer and the herb layer was highest at mid-elevation, underscoring the importance of protecting mid-elevation ecosystems. Climatic distance and topographic distance were more influential than spatial distance in driving the species composition change of shrubs and herbs. In the herb layer, climatic, topographic, and spatial factors contributed more to community assembly than shrub communities. In this case, improving the environment in the community or introducing herbs could help the restoration of these places. These findings provide insight into biogeographic patterns, biodiversity growth mechanisms, and community formation processes. Moreover, it can improve projections of climate change within and across ecosystems and provide the scientific basis for the use and management of plant resources in arid and semi-arid regions.

Personalized statistical modeling of soft tissue structures in the knee.

Background and Objective: As in vivo measurements of knee joint contact forces remain challenging, computational musculoskeletal modeling has been popularized as an encouraging solution for non-invasive estimation of joint mechanical loading. Computational musculoskeletal modeling typically relies on laborious manual segmentation as it requires reliable osseous and soft tissue geometry. To improve on feasibility and accuracy of patient-specific geometry predictions, a generic computational approach that can easily be scaled, morphed and fitted to patient-specific knee joint anatomy is presented. Methods: A personalized prediction algorithm was established to derive soft tissue geometry of the knee, originating solely from skeletal anatomy. Based on a MRI dataset (n = 53), manual identification of soft-tissue anatomy and landmarks served as input for our model by use of geometric morphometrics. Topographic distance maps were generated for cartilage thickness predictions. Meniscal modeling relied on wrapping a triangular geometry with varying height and width from the anterior to the posterior root. Elastic mesh wrapping was applied for ligamentous and patellar tendon path modeling. Leave-one-out validation experiments were conducted for accuracy assessment. Results: The Root Mean Square Error (RMSE) for the cartilage layers of the medial tibial plateau, the lateral tibial plateau, the femur and the patella equaled respectively 0.32mm (range 0.14-0.48), 0.35mm (range 0.16-0.53), 0.39mm (range 0.15-0.80) and 0.75mm (range 0.16-1.11). Similarly, the RMSE equaled respectively 1.16mm (range 0.99-1.59), 0.91mm (0.75-1.33), 2.93mm (range 1.85-4.66) and 2.04mm (1.88-3.29), calculated over the course of the anterior cruciate ligament, posterior cruciate ligament, the medial and the lateral meniscus. Conclusion: A methodological workflow is presented for patient-specific, morphological knee joint modeling that avoids laborious segmentation. By allowing to accurately predict personalized geometry this method has the potential for generating large (virtual) sample sizes applicable for biomechanical research and improving personalized, computer-assisted medicine.

Topographical distance between presynaptic Ca2+ channels and exocytotic Ca2+ sensors contributes to differential facilitatory actions of roscovitine on neurotransmitter release at cerebellar glutamatergic and GABAergic synapses.

Calcium influx into presynaptic terminals through voltage-gated Ca2+ channels triggers univesicular or multivesicular release of neurotransmitters depending on the characteristics of the release machinery. However, the mechanisms underlying multivesicular release (MVR) and its regulation remain unclear. Previous studies showed that in rat cerebellum, the cyclin-dependent kinase inhibitor roscovitine profoundly increases excitatory postsynaptic current (EPSC) amplitudes at granule cell (GC)-Purkinje cell (PC) synapses by enhancing the MVR of glutamate. This compound can also moderately augment the amplitude and prolong the decay time of inhibitory postsynaptic currents (IPSCs) at molecular layer interneuron (MLI)-PC synapses via MVR enhancement and GABA spillover, thus allowing for persistent activation of perisynaptic GABA receptors. The enhanced MVR may depend on the driving force for Cav 2.1 channel-mediated Ca2+ influx. To determine whether the distinct spatiotemporal dynamics of presynaptic Ca2+ influence MVR, we compared the effects of slow and fast Ca2+ chelators, that is, EGTA and BAPTA, respectively, on roscovitine-induced actions at GC-PC and MLI-PC synapses. Membrane-permeable EGTA-AM decreased GC-PC EPSC and MLI-PC IPSC amplitudes to a similar extent but suppressed the roscovitine-induced enhancement of EPSCs. In contrast, BAPTA-AM attenuated the effects of roscovitine on IPSCs. These results suggest that roscovitine augmented glutamate release by activating the release machinery located distally from the Cav 2.1 channel clusters, while it enhanced GABA release in a manner less dependent on those at distal sites. Therefore, the spatial relationships among Ca2+ channels, buffers, and sensors are critical determinants of the differential facilitatory actions of roscovitine on glutamatergic and GABAergic synapses in the cerebellar cortex.

Blowin’ in the wind: Wind directionality affects wetland invertebrate metacommunities in Patagonia

AbstractAimTo assess the relative importance of wind intensity and direction in explaining wetland invertebrate metacommunity organization.LocationSeventy‐eight wetland ponds in Patagonia (Argentina) covering a study area of 3.5 × 105 km2.Time periodPonds were sampled once between 2006 and 2014.Major taxa studiedOne hundred and fifty‐eight taxa of wetland aquatic invertebrates.MethodsWe generated two beta diversity matrices (based on flying and non‐flying invertebrates) and six predictor matrices, including three environmental distance matrices, a topographic distance between ponds, and two wind pairwise matrices differing in wind speed. Using Moran spectral randomization of Mantel (MSR‐Mantel) tests (which account for spatial autocorrelation), we assessed the relationship between the response and the predictor matrices. We used a network‐constrained version of the nestedness metric based on overlap and decreasing fill (NODF), to assess if wind anisotropy (i.e., direction‐dependent) affected community nestedness among ponds.ResultsFlying dispersers’ dissimilarity was significantly explained by environmental variables, whereas non‐flying invertebrates’ dissimilarity was not significantly explained by any of the distances tested. When wind direction was ignored, wind speed had a negligible effect on both types of communities, whereas when it was considered a consistent nested pattern emerged, with the eastern ponds (downwind) communities being subsets of those from the western ponds (upwind).Main conclusionsWe found that the invertebrate communities were mainly assembled by a combination of environmental factors and wind directionality, although this depended on the dispersal ability of the organisms.

Electrophysiological correlates of the somatotopically organized tactile duration aftereffect

Adaptation to sensory events of long or short duration leads to a negative aftereffect, in which a new target event (of median duration) following the adaptation will be perceived to be shorter or longer than is actually the case. This illusion has been observed in visual, auditory, and tactile modalities. This study used event-related potentials (ERPs) to examine the tactile duration aftereffect, using the contingent negative variation (CNV) and the late positive component (LPC) as a way to characterize the temporal processes. The tactile duration adaptation was found to induce a significant aftereffect within a somatotopic framework. Moreover, the CNV in the contralateral scalp and the LPC in the fronto-central scalp were both modulated by the tactile duration adaptation. Specifically, adaptation to a short tactile duration increased the CNV and LPC amplitudes, whereas adaptation to a long tactile duration decreased them. This modulation was contingent on the topographic distance between fingers, which was only observed when the adapting and test fingers were consistent or adjacent, but not homologous. In sum, these results reveal a coherent behavioral-electrophysiological link in the somatotopically organized tactile duration aftereffect.

Geographies of Holocaust rescue: Spatial patterns and social geographies of Jewish rescue in Budapest, 1944

In this article we seek to extend the literature on Holocaust geographies through a case study of geographies of rescue in Budapest in 1944. Drawing on mixed qualitative and quantitative methods, we place Raoul Wallenberg and the Swedish legation’s rescue work within the multiple geographies of wartime Budapest, as well as offer broader reflections on the value and limits of spatial analytical methods within geographies of the Holocaust. Working with an historical GIS of the Budapest ghetto, a database created from the largest surviving Swedish list and a post–war count of survivors, as well as the personal narratives of survivors, the article examines how social status and social networks may contribute to explain the profiles of those rescued. Rather than topographic distance being key, the article argues that another geography–one of socioeconomic power–was more significant. We see this article making two main contributions to the current literature. Firstly, it interrogates ideas of distance as both a topographic and a topological category, as well as signaling the need to consider both abstract space and lived place in developing ‘integrated’ geographies of the Holocaust. Secondly, in doing this, it explores the possibilities and limitations of a range of spatial–analytical tools and approaches to interrogate geographies of rescue, and other areas of interest to historical geographers.

As time goes by: 20 years of changes in the aquatic macroinvertebrate metacommunity of Mediterranean river networks

AbstractAimTo analyse temporal metacommunity dynamics in river networks in relation to hydrological conditions and dispersal.LocationFifteen river reaches from the Llobregat, Besòs and Foix catchments in the North‐Eastern Iberian Peninsula.TaxonAquatic macroinvertebrates belonging to 99 different families.MethodsWe sampled aquatic macroinvertebrate communities during spring in 20 consecutive years. We built two environmental distances (one related with water chemistry and another one with river flow regime) and two spatial distances (network distance and topographic distance). Then we used Mantel tests (accounting for spatial autocorrelation) to relate macroinvertebrate dissimilarity with environmental and spatial distances. Additionally, we determined the dry and wet years using the Standardized Precipitation Index (SPI) and we classified macroinvertebrate families based on their ability to fly and to drift. Finally, we ran a linear regression model including the correlation value (r) of each Mantel test as response variable and distance type (environmental or spatial), SPI, dispersal mode, their pairwise interactions and a three‐way interaction as predictor variables.ResultsMetacommunity organization varied over time and it was significantly affected by precipitation, which can be related to river network connectivity. The environmental filters, mainly the flow regime, were generally more important than the spatial filters in explaining community dissimilarity over the study period. However, this depended on the dispersal abilities of the organisms. Network fragmentation due to flow intermittence during the dry years significantly reduced the dispersal capacity of strong aerial dispersers, leading to spatially structured metacommunities. For strong drift dispersers, community dissimilarity patterns were generally best explained by environmental filters regardless of SPI.Main conclusionsA significant temporal variation in metacommunity organization can be expected in highly dynamic systems (e.g. Mediterranean rivers) and it might depend on the dispersal modes and abilities of the organisms, since they determine the response to changes in environmental and landscape filters.

Topography and post-fire climatic conditions shape spatio-temporal patterns of conifer establishment and growth

BackgroundConcern is mounting that larger, stand-replacing forest fires may accelerate compositional shifts or conversions to non-forested states under a warming climate. Post-fire climatic conditions influence system trajectories by facilitating or hindering juvenile recruitment. But without an accurate, long-term understanding of where, when, and how climatic variability and other ecological factors affect regeneration, our ability to predict post-fire trajectories is limited. I quantified multiple, interacting facets of post-fire conifer regeneration—including annual establishment rates and growth—one decade after stand-replacing fire on the eastern slopes of the North Cascades, Washington, USA. Sites were stratified across topographic settings to specifically capture the potential for topography to moderate seasonal and interannual climatic conditions.ResultsRecruitment of juvenile conifers occurred every year since fire, with considerable species-specific variability across topographic settings and distance to seed source. Juveniles of all species, except lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson), were rarely observed when live, conspecific seed source was more than 75 m away. Lodgepole pine was the only species for which greater distance to live seed source was not associated with lower densities, a pattern attributable to serotiny. Annual establishment rates were strongly correlated with post-fire conditions: rates were highest when growing seasons were relatively cool and moist. A lagged climate signal was apparent in annual growth rates, but standardized climate–growth relationships did not vary across topographic settings, suggesting that topographic setting did not decouple site conditions from broader climatic trends to a degree that affected growth patterns.ConclusionsThese results underscore the importance of favorable post-fire climatic conditions in promoting robust establishment and growth while also highlighting the importance of topography and endogenous, stand-level processes (e.g., seed availability and delivery) in shaping recovery over time. Furthermore, these results suggest that, while the growing concern of post-fire regeneration failure may indeed be warranted under some conditions, failure is not yet the rule in all places and at all times. A more detailed understanding of recovery dynamics through long-term monitoring and by examining multiple, interacting facets of regeneration across scales will improve our predictions of where and when regeneration failure or, conversely, robust recovery may occur under a changing climate.

Winter movement behavior by swift foxes (Vulpes velox) at the northern edge of their range

Winter can be a limiting time of year for many temperate species, who must access depressed prey resources to meet energetic demands. The swift fox (Vulpes velox (Say, 1823)) was extirpated from Canada and Montana (USA) by 1969, but was reintroduced in the 1980s to Canada, and subsequently spread into northern Montana. Swift foxes in this region are at the current northern range edge where winter conditions are harsher and persist longer than in their southern range (i.e., Colorado (USA) to Texas (USA)). We collected fine-scale locational data from swift foxes fitted with global positioning system collars to examine movement and resource-use patterns during winter of 2016–2017 in northeastern Montana. Our results suggest that swift foxes displayed three distinct movement patterns (i.e., resting, foraging, and travelling) during the winter. Distance to road decreased relative probability of use by 39%–46% per kilometre across all movement states and individuals, whereas the influence of topographic roughness and distance to crop field varied among movement states and individuals. Overall, while our findings are based on data from three individuals, our study suggests that across movement states during the critical winter season, swift foxes are likely using topography and areas near roads to increase their ability to detect predators.

Measuring distance through topographic models

Abstract. Accurate measurement of distances is of paramount importance to transportation infrastructure planning. Be it for estimating travel time, locating accidents and hazards through road markers, planning maintenance services, or setting prices for building contracts, distance is the primary metric upon which all aspects of the job are based, given that transportation infrastructure deals mostly with linear features. Yet, countries with older infrastructure often don’t know for how long their networks run – especially so in case of developing countries. Brazil currently has over 2640000 km of roads, with construction documentation lacking for most of the network. The most used method for generating distance measurements, the car odometer from driving between two points, while apt for doing macro-regional planning, is unfit for large-scale engineering work, as this study shows below.The industry standard for measuring distances uses a precision odometer connected to specialized tires, used either on their own or as a “fifth wheel” on a vehicle. Such method, however, is laborious and slow, and only generates a scalar between two points, with any new distance necessitating a new measurement, even if the two sets share a common space, or if one distance is a subset of the other. This paper proposes the usage of systematic mapping techniques to generate topographic linear features with measuring information, from which any distance can be calculated. To generate these features, first a linear path is constructed in GIS software over a route. The height information of each node in the path is then extracted from a source, and then the topographic distance is calculated from the vertical profile. Finally, an M coordinate is generated for each node.For comparison between sources, a base path was used as ground truth. This path was constructed from a GNSS survey along the road, collected on cinematic mode at 10Hz (1.1 m gap between points), and post-processed with fixed-phase relative positioning tied to a base station. The mean positional quality achieved was 2.5 cm of planimetric, and 4.3 cm of altimetric precision. Two other sources of height information were used for comparison, one a flight DTM with 33 cm LE90 and 1 m of cell size, and the NASA 1 Arc-second SRTM with a nominal 9 m LE90 and 30 m cell size. Furthermore, a planimetric distance using a navigational GPS device (C/A code only) was also calculated. Two highways were selected for testing, and divided into 341 segments of 200 meters each, to account for the influence of slope in the calculations.As expected, the flight DTM came the closest to the base model, deviating from it at an average of 31.95 ppm, with 2.8 ppm of standard error. It is, however, the most expensive and time-consuming method. The SRTM deviated an average of 5131.53 ppm and showed very high variation, with 8481.96 ppm of standard error. The navigation GPS deviated at an average of 685.18 ppm, with 633.11 ppm of standard error. Both the SRTM and GPS appear to deviate further from the base model as slope increases, but given that few segments with over 2.5° of slope were present in the sample, a correlation could not yet be established. For comparison, the average of the car odometer method was 16654.51 ppm, with a standard error of 22661.69 ppm. Given its high deviation, the SRTM is unfit for precision work, but is a big improvement over using the car odometer for general indications. Further studies with mid-range DTMs should be done to provide a remote sensing alternative. The handheld GPS had better results than expected, given its nominal precision of 15 m. Despite a probable larger absolute positioning error, its relative error distribution remained steady enough to allow a good distance measurement.

A bibliometric analysis of the interdisciplinary field of cultural evolution

The science of cultural evolution is unified in its application of evolutionary logic to socially transmitted behavior, but diverse in methodologies and assumptions. Qualitative reviews have encouraged integration by illuminating points of divergence and fostering interaction. This effort would be greatly enhanced by quantitative data on patterns of collaboration and idea sharing in the literature. In the present study, we apply a novel combination of network, cluster, and bibliometric analyses to an extensive dataset of publications on cultural evolution, in order to represent the structure of the field and evaluate the level of disciplinary integration. We first construct a co-authorship network and identify subdisciplines. We then use bibliometric analyses to describe each subdiscipline and investigate trends in collaboration and productivity. Lastly, we assess the topographical distance and degree of citation sharing between subdisciplines, as well as the diversity of subject categories within subdisciplines. Our results reveal an increase in productivity and collaboration over time, albeit a higher inequality in author productivity than expected. Our structural approach reveals research subcommunities with differential levels of integration, citation sharing, and subject diversity. These findings confirm the emergence of a vigorous interdisciplinary field, and indicate ways to foster integration and synthesis in cultural evolution.

The Problem of Transportation Infrastructure Development in Papua Region Indonesia

The eastern region of Indonesia, Papua, decentralized government administration has been divided into 2 (two) provinces, namely West Papua Province with provincial capital of Manokwari and Papua Province with provincial capital of Jayapura. Judging from the history of all the existing provinces, the last territory of independence becomes part of the territory of the Unitary State of the Republic of Indonesia. The Republic of Indonesia was established in 1945, and this easternmost region entered as part of the territory of the Republic of Indonesia in 1962. The number and density of its population are the fewest. The development of this area continues to be carried out, various concepts of development planning continue to be developed and implemented. Progress was achieved in several aspects of community life. However, the results achieved have not been as expected. The infrastructure network that has been built has not been successful in balancing the issues of inequality and equity in the context of the whole of Indonesia as a unified infrastructure system that supports all sectors of the lives of citizens, especially the economic and social sectors. Infrastructure is meant here is the infrastructure that is the responsibility of the government in the ministry of communications and the ministry of public works and public housing.
 
 Constraints of topographic conditions, rare population, cultural perceptions, and distance coverage of the already advanced areas are issues that need to be addressed and solved alternative solutions. The system constraints of all infrastructure and the priority of which components must be built first and the priority of the location also become individual issues, which in this system will also include power supply system, fuel, and cement as the main material of infrastructure building.
 
 This paper summarizes and discusses some of the results of discussions and studies related to the acceleration of infrastructure development in Papua.

Morphometric study of the semitendinosus muscle and its neurovascular pedicles in South Indian cadavers.

The purpose of this study was to determine the length of the semitendinosus muscle belly and its tendon in South Indian population and to study the topography and diameter of its neurovascular pedicles. The study included 46 formalin fixed human cadaveric lower limbs. The length of the semitendinosus muscle belly and its tendon were measured. The neurovascular pedicles of the semitendinosus muscle were identified and counted. The diameter of the neurovascular pedicle was measured just before its entrance into the semitendinosus muscle. The topographical distance of the neurovascular pedicles from the origin of the semitendinosus muscle were determined. The mean length of the semitendinosus muscle belly was 332.3±36.1 mm and its tendon measured 154.8±31.9 mm. The mean diameter of the vascular pedicle was measuring 11.4±9.1 mm, just before its entrance into the semitendinosus muscle. The neurovascular pedicles, of the semitendinosus muscle were ranging between 1 and 7. The distance of the entrance of neurovascular pedicle to the semitendinosus muscle from its origin was ranging between 46 and 272 mm. It was observed that the neurovascular pedicles were highest (31%) at the range of 151–200 mm away from the ischial tuberosity. The morphometric data obtained in the present study is enlightening to the orthopedic and plastic surgeons. The topographical knowledge of the neurovascular pedicles has its implications during the harvesting of the grafts and pedicle flaps. The diameter of vessels in the pedicles is enlightening because of new method of anterior cruciate ligament reconstruction.

Beyond modularity: Fine-scale mechanisms and rules for brain network reconfiguration

The human brain is in constant flux, as distinct areas engage in transient communication to support basic behaviors as well as complex cognition. The collection of interactions between cortical and subcortical areas forms a functional brain network whose topology evolves with time. Despite the nontrivial dynamics that are germane to this networked system, experimental evidence demonstrates that functional interactions organize into putative brain systems that facilitate different facets of cognitive computation. We hypothesize that such dynamic functional networks are organized around a set of rules that constrain their spatial architecture – which brain regions may functionally interact – and their temporal architecture – how these interactions fluctuate over time. To objectively uncover these organizing principles, we apply an unsupervised machine learning approach called non-negative matrix factorization to time-evolving, resting state functional networks in 20 healthy subjects. This machine learning approach automatically groups temporally co-varying functional interactions into subgraphs that represent putative topological modes of dynamic functional architecture. We find that subgraphs are stratified based on both the underlying modular organization and the topographical distance of their strongest interactions: while many subgraphs are largely contained within modules, others span between modules and are expressed differently over time. The relationship between dynamic subgraphs and modular architecture is further highlighted by the ability of time-varying subgraph expression to explain inter-individual differences in module reorganization. Collectively, these results point to the critical role that subgraphs play in constraining the topography and topology of functional brain networks. More broadly, this machine learning approach opens a new door for understanding the architecture of dynamic functional networks during both task and rest states, and for probing alterations of that architecture in disease.

Mapping Techniques of Spatiotemporal Relationships for a Centric Road Network Model

The aim of the study is to determine the effectiveness of cartographic representation methods based on the proportion of correct decisions for each map, as well as users’ perceived effectiveness and their subjective evaluation of the graphical attractiveness of the mapping techniques used to convey information about spatio temporal accessibility. Several visualisations (both traditional and less conventional) are used to show distances between points in an hypothetical centric road network model. The relationships between the starting point and the destination points are considered in three ways: the Euclidean distance, the topographic distance measured along the roads, and the temporal distance. Fifty students were asked to estimate shortest, longest and matching distances and to pick out from the options the most effective and the most graphically attractive method of portrayal. The best result was achieved for two-dimensional mapping techniques with information about accessibility level labelled directly on the map. Students also performed better when seeking the shortest distances between central and destination point, and the best estimation results were achieved for the Euclidean distance.

The East Africa Oligocene intertrappean beds: Regional distribution, depositional environments and Afro/Arabian mammal dispersals

The East Africa Oligocene intertrappean beds: Regional distribution, depositional environments and Afro/Arabian mammal dispersals

Fuzzy Color Image Segmentation using Watershed Transform

In this paper, we present a segmentation technique which joins a multi-scale texture based approach and a fuzzy segmentation method using the color gradient of Di Zenzo. Thus maps of homogeneous texture patterns are enhanced by edge localization. A topographic distance is used to calculate membership degrees to each region. Both lead to segmentation using a step of watershed flooding, with few parameters to set. Moreover computation complexity has been reduced to allow treatments of images in full size and colors. 