The morphological differences between two geographical maps can be highlighted by a polycentric distance cartogram resulting from a bidimensional regression.Beyond the communicational interest of the transformations t...The morphological differences between two geographical maps can be highlighted by a polycentric distance cartogram resulting from a bidimensional regression.Beyond the communicational interest of the transformations thus produced,the method makes it possible to reveal the differences in structure and therefore constitutes a real research tool.However,bidimensional regression can only compare the shape of two maps.Since the 1990s,geometric morphometrics has revolutionized the morphological analysis of natural structures(and others).It has since been applied in many fields of research but not in cartography.This article describes the theoretical and methodological bases of a method combining bidimensional regression with a geometric morphometrics approach to compare the shape of several geographical maps.Geometric morphometrics and bidimensional regression indeed share common approaches of the statistical shape analysis like homologous landmarks and interpolation grids.However,there is no software in geometric morphometrics capable of directly reading geographical data,which would facilitate the work of cartographers accustomed to GIS software.That is why we present MapMorphy,a tool specifically developed for this task.An example on ancient maps illustrates the method.展开更多
T his study compared and evaluated the efficiency of two otolith shape descriptors(i.e., the elliptic Fourier transform(EFT) and discrete wavelet transform(DWT)) and morphometrics for stock discrimination. To accompli...T his study compared and evaluated the efficiency of two otolith shape descriptors(i.e., the elliptic Fourier transform(EFT) and discrete wavelet transform(DWT)) and morphometrics for stock discrimination. To accomplish this, sample fish from three stocks of yellow croaker L arimichthys polyactis along the Chinese coast(LDB stock from the Liaodong Bay of the Bohai Sea, JZB stock from the Jiaozhou Bay of the Yellow Sea and CJE stock from the Changjiang River estuary of the East China Sea) were used for otolith morphology analyses. The results showed that morphometrics produced an overall classification success rate of 70.8% in contrast with success rates of 80.0% or 82.0% obtained using EFT or DWT, respectively. This suggests that the two shape descriptors comparably discriminated among the stocks and performed more efficiently than morphometrics. During data adjustment and acquisition, some size variables were excluded from the subsequent discriminant analysis for stock discrimination because they were statistically "inef fective," which could reduce the efficiency of morphometrics and lead to relatively low overall classification success. Both EFT and DWT retain the contour coefficients and thus provide a detailed description of otolith shape, which could improve discriminatory efficiency compared with morphometrics.展开更多
As a more efficient quantitative method for morphological analysis, geometric morphometrics is applied to the flabellate fossils Flabellophyton including Flabellophyton lantianensis and Flabellophyton strigata from Ne...As a more efficient quantitative method for morphological analysis, geometric morphometrics is applied to the flabellate fossils Flabellophyton including Flabellophyton lantianensis and Flabellophyton strigata from Neoproterozoic Ediacaran Lantian biota, South China. Both traditional morphometric analysis (including diverging angle, length, and width distribution) and geometric morphometric analysis [including superposition of normalized area analysis, non-metric multidimensional scaling (n-MDS), Bray-Curtis similarity cluster analysis (CLUSTER) and analysis of similarities (ANOSIM)[ were performed. The results indicate there are great interspecific morphological differences between F. lantianensis and F. strigata, in addition to some intraspecific variations within each species. Here we preliminarily suggest that the previously defined Flabellophyton should be subdivided into 2 genera at least: one marked by the dark transverse striated structure, and the other without. This recharacterization and reclassification work still needs further careful observation and comprehensive analysis with large number of flabeilate fossils combining morphology, structure, population, and community-ecology study.展开更多
Pikas(Lagomorpha: Ochotonidae) are small mouselike lagomorphs. To investigate their adaptation to different ecological environments during their dispersal from the Qinghai-Xizang(Tibet) Plateau(QTP), we collected 226 ...Pikas(Lagomorpha: Ochotonidae) are small mouselike lagomorphs. To investigate their adaptation to different ecological environments during their dispersal from the Qinghai-Xizang(Tibet) Plateau(QTP), we collected 226 pikas and measured 20 morphological characteristics and recorded habitat information. We also sequenced the genome of 81specimens, representing 27 putative pika species.The genome-wide tree based on 4?090 coding genes identified five subgenera, i.e., Alienauroa, Conothoa,Lagotona, Ochotona, and Pika, consistent with morphometric data. Morphologically, Alienauroa and Ochotona had similar traits, including smaller size and earlier divergence time compared to other pikas.Consistently, the habitats of Alienauroa and Ochotona differed from those of the remaining subgenera. Phylogenetic signal analysis detected 83 genes significantly related to morphological characteristics, including several visual and hearingrelated genes. Analysis of shared amino acid substitutions and positively selected genes(PSGs) in Alienauroa and Ochotona identified two genes, i.e.,mitochondrial function-related TSFM(p.Q155E) and low-light visual sensitivity-related PROM1(p.H419Y).Functional experiments demonstrated that TSFM-155E significantly enhanced mitochondrial function compared to TSFM-155Q in other pikas, and PROM1-419Y decreased the modeling of dynamic intracellular chloride efflux upon calcium uptake. Alienauroa and Ochotona individuals mostly inhabit different environments(e.g., subtropical forests) than other pikas, suggesting that a shift from the larger ancestral type and changes in sensory acuity and energy enhancement may have been required in their new environments. This study increases our understanding of the evolutionary history of pikas.展开更多
The morphology of seven specimens of Chrysaora chinensis(Scyphomedusae,Semaestomae)obtained from four sites off the coast of Peninsular Malaysia was examined.Morphological characteristics of C.chinensis that encompass...The morphology of seven specimens of Chrysaora chinensis(Scyphomedusae,Semaestomae)obtained from four sites off the coast of Peninsular Malaysia was examined.Morphological characteristics of C.chinensis that encompasses structures such as the bell,tentacles,oral arms,stomach,manubrium,radial canals and gonads were described in detail.A total of 107 specimens that represented C.chinensis populations of four coastal areas of Peninsular Malaysia(East-Central,East-North,West-Central,and West-North)were also analysed for shape variation using geometric morphometric analysis.Procrustes superimposition,Principal Component Analysis(PCA)and Canonical Variate Analysis(CVA)were applied to the images of gastrovascular pouches of C.chinensis to extract the shape information.Independent contrasts were used for comparisons between shapes.There were no significant differences in shape variation between all the specimens based on the PCA results.However,CVA results showed shape variations between specimens taken from the four areas of Peninsular Malaysia,especially with higher magnitudes of Mahalanobis distances between the east and west coast areas,including between East-Central and East-North,but lower magnitudes were detected between the West-Central and West-North.展开更多
The Upper Ordovician Xiazhen Formation in the Jiangshan-Changshan-Yushan (JCY) triangle area on the Zhejiang-Jiangxi provincial border, South China, is composed of a mixed carbonate-siliciclastic sequence representi...The Upper Ordovician Xiazhen Formation in the Jiangshan-Changshan-Yushan (JCY) triangle area on the Zhejiang-Jiangxi provincial border, South China, is composed of a mixed carbonate-siliciclastic sequence representing various shallow-water platform environments. Highly diversified and abundant heliolitid coral faunas are recognized in the formation and occur over time and space in certain stratigraphic horizons and various lithofacies. Heliolites has been studied using multivariate morphometric analysis applied to differentiate species and evaluate intraspecific and interspecific variations. Ten morphological characters quantified by examination and measurement from transverse and longitudinal thin sections and statistically tested allowed selection of effective characters to discriminate species. Results of frequency histograms, correlation analysis and principle component analysis indicated that certain characters would be suitable for cluster analysis, which were performed on principle component score matrices obtained from the raw data set coordinated with coralla by all those characters. Five major clusters at a relative distance of five on the resulting dendrogram of Heliolites are regarded as morphospecies thus making valid taxa: Heliolites tashanensis Lin and Chow, 1977; Heliolites caracolica (Lin and Chow, 1977); Heliolites columella (Lin and Chow, 1977); Heliolites waicunensis Lin and Chow, 1977; and H. sinensis irregularis Lin and Chow, 1977. The discrimination of these morphospecies by the cluster analysis is verified by discriminant analyses and descriptive statistics.展开更多
BACKGROUND The development of precision medicine is essential for personalized treatment and improved clinical outcome,whereas biomarkers are critical for the success of precision therapies.AIM To investigate whether ...BACKGROUND The development of precision medicine is essential for personalized treatment and improved clinical outcome,whereas biomarkers are critical for the success of precision therapies.AIM To investigate whether iCEMIGE(integration of CEll-morphometrics,MIcro-biome,and GEne biomarker signatures)improves risk stratification of breast cancer(BC)patients.METHODS We used our recently developed machine learning technique to identify cellular morphometric biomarkers(CMBs)from the whole histological slide images in The Cancer Genome Atlas(TCGA)breast cancer(TCGA-BRCA)cohort.Multivariate Cox regression was used to assess whether cell-morphometrics prognosis score(CMPS)and our previously reported 12-gene expression prognosis score(GEPS)and 15-microbe abundance prognosis score(MAPS)were independent prognostic factors.iCEMIGE was built upon the sparse representation learning technique.The iCEMIGE scoring model performance was measured by the area under the receiver operating characteristic curve compared to CMPS,GEPS,or MAPS alone.Nomogram models were created to predict overall survival(OS)and progress-free survival(PFS)rates at 5-and 10-year in the TCGA-BRCA cohort.RESULTS We identified 39 CMBs that were used to create a CMPS system in BCs.CMPS,GEPS,and MAPS were found to be significantly independently associated with OS.We then established an iCEMIGE scoring system for risk stratification of BC patients.The iGEMIGE score has a significant prognostic value for OS and PFS independent of clinical factors(age,stage,and estrogen and progesterone receptor status)and PAM50-based molecular subtype.Importantly,the iCEMIGE score significantly increased the power to predict OS and PFS compared to CMPS,GEPS,or MAPS alone.CONCLUSION Our study demonstrates a novel and generic artificial intelligence framework for multimodal data integration toward improving prognosis risk stratification of BC patients,which can be extended to other types of cancer.展开更多
In order to incorporate the knowledge of two species of wild doves and compare the results of both, we assessed morphometrics (body weight, bill, tarsus, tail, wing, head and culmen length) and body condition index (u...In order to incorporate the knowledge of two species of wild doves and compare the results of both, we assessed morphometrics (body weight, bill, tarsus, tail, wing, head and culmen length) and body condition index (using weigh, wing, tail and tarsus length) of Eurasian Collared-Dove Streptopelia decaocto and Mourning Dove Zenaida macroura (Aves: Columbidae) based on 40 specimens of each species collected during fall-winter 2013 and spring-summer 2014 in the municipality of Durango, Durango, Mexico. We found that body condition index was higher during fallwinter for both species. We also found size dimorphism. Males of Eurasian Collared-Dove were larger than females in head length (p = 0.002) and tail length (p = 0.05) but smaller in culmen length. Female Mourning Doves had a higher body condition index compared to males (p = 0.02) during both seasons. As expected, Eurasian Collared-Dove was larger in all measurements than Mourning Dove (p > 0.05) but tail length (p = 0.12).展开更多
The morphological characteristics of the hind wing venation of tetrigids were analyzed on the basis of morphometric measurement, with 20 species and 18 different variables selected for this study. Results show that th...The morphological characteristics of the hind wing venation of tetrigids were analyzed on the basis of morphometric measurement, with 20 species and 18 different variables selected for this study. Results show that three principal components have a higher load at the length between the starting point of the costal vein and the tip of the fourth anal vein, between the tip of the costal vein and the tip of the third anal vein, and between the tip of the costal vein and the tip of the eleventh anal vein. There exists a contrast between wing length and width.展开更多
Morphometrics has been pursued by graphical and computational means since the European Renaissance, drawing on core geometric principles first discovered in China and Classical Greece. Through the late 1800s, two dist...Morphometrics has been pursued by graphical and computational means since the European Renaissance, drawing on core geometric principles first discovered in China and Classical Greece. Through the late 1800s, two distinct approaches to such analyses were pursued: a deformationist approach, epitomized by D'Arcy Thompson's graphical trans-formation grids and the statistical approach popularized by Francis Galton, Karl Pearson, and Julian Huxley in which Cartesian spaces were employed to summarize patterns of variation in size and/or shape variables. Unification of these approaches was an off-stated goal throughout the 20th century, but proved elusive until the mid-1980s when David Kendall, Fred Bookstein, and Colin Goodall proposed a radically new way of understanding form -- as the locations of configurations of landmarks on the surfaces of a nested series of hyperdimensional manifolds. Once this new mathematics of form was understood development of basic concepts, procedures, graphical tools, and statistical tests followed quickly such that the core of the long-hoped for synthesis took less than a decade to achieve. The result-- geometric morphometrics -- continues to develop into an ever-more extensive toolkit that can be used by researchers to describe and understand a wide range of problems involving the characterization of morphological similarities and differences in all of their many and varied contexts. In particular, the new approaches involving the direct analysis of image pixels and new tools such as machine learning and artificial intelligence are set to reinvigorate (and possibly to revolutionize) the field once again.展开更多
Although there were many ancient Chinese mathematicians contributed a lot on geometry, Geometric morphometrics (GM) in modern concept was not firstly proposed by Chinese. The super capability of geometric morphometr...Although there were many ancient Chinese mathematicians contributed a lot on geometry, Geometric morphometrics (GM) in modern concept was not firstly proposed by Chinese. The super capability of geometric morphometries in scientific computing and problem solving has gained a lot of attentions in the world. Until early of 21 centuries, geometric morphometries was introduced into China. Since then, GM was rapidly applied in many research fields. However, it is a pity that GM is still not well-known in China as many works are published out of China. Thus, the special issue "Geometric morphometrics: Current shape and future directions" is organized. The present issue presents a series of contributions in this scientific field. In future, there will be many considerable new developing fields on GM needed to pay more attentions, for instances, 3D geometric morphometrics, 4D analysis, visualization of amber, new machine developing, new software developing, automatic identification system, etc. Once these technical bottle-necks on 3D data collecting and merging geometric morphometric data from multiple characters could be solved, the automatic identification system and other fields based on Big Data would come true.展开更多
The main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic fa...The main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic factors.Mud circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of Mount Honaz.Pearson's correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).To explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and analysed.Periglacial landforms,which continue to develop on the summits of Mount Honaz today,have been evaluated with present climate data.Analysis of soil samples indicates a notable impact of parent material on the genesis of periglacial landforms.The high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil properties.Furthermore,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.展开更多
The mammalian family Bovidae has been widely studied in ecomorphological research,with important applications to paleoecological and paleohabitat reconstructions.Most studies of bovid craniomandibular features in rela...The mammalian family Bovidae has been widely studied in ecomorphological research,with important applications to paleoecological and paleohabitat reconstructions.Most studies of bovid craniomandibular features in relation to diet have used linear measurements.In this study,we conduct landmark-based geometric-morphometric analyses to evaluate whether different dietary groups can be distinguished by mandibular morphology.Our analysis includes data for 100 species of extant bovids,covering all bovid tribes and 2 dietary classifications.For the first classification with 3 feeding categories,we found that browsers(including frugivores),mixed feeders,and grazers are moderately well separated using mandibular shape.A finer dietary classification(frugivore,browser,browser-grazer intermediate,generalist,variable grazer,and obligate grazer)proved to be more useful for differentiating dietary extremes(frugivores and obligate grazers)but performed equally or less well for other groups.Notably,frugivorous bovids,which belong in tribe Cephalophini,have a distinct mandibular shape that is readily distinguished from all other dietary groups,yielding a 100%correct classification rate from jackknife cross-validation.The main differences in mandibular shape found among dietary groups are related to the functional needs of species during forage prehension and mastication.Compared with browsers,both frugivores and grazers have mandibles that are adapted for higher biomechanical demand of chewing.Additionally,frugivore mandibles are adapted for selective cropping.Our results call for more work on the feeding ecology and functional morphology of frugivores and offer an approach for reconstructing the diet of extinct bovids.展开更多
The scope of shape analysis based on geometric morphometrics has evolved into underscoring complex patterns of multidimensional shape change with multivariate statistical modelling (e.g., allometry, morphological int...The scope of shape analysis based on geometric morphometrics has evolved into underscoring complex patterns of multidimensional shape change with multivariate statistical modelling (e.g., allometry, morphological integration, etc.). Such breakthrough was made possible because the method relies on a consistent comparative reference system to compare shapes, the latter which is computed using the Cartesian coordinates of homologous landmarks. It has been shown elsewhere that traditional comparative reference systems based on anatomy, and oriented in stereotyped postures, such as the Frankfurt plane at rest, the Lateral Semicircular Canal when the animal is in alert, or the cranial floor when the animal is flying, are all inconsistent for anatomical comparisons. They vary too much and unpredictably across species. An extraordinary example of the problems that can arise in descriptive and comparative anatomy when using such reference systems is the traditional interpretation of the head of the Woodcock. Anywhere in literature it is written that the eyes of this gamebird are oriented backwards to protect itself from predators. Here, using geometric morphometrics it is demonstrated that the woodcock's skull is highly transformed, yet following a normal trend among birds. In turn, using GM it is demonstrated that the collective wisdom about this oddity is simply the result of interpreting the anatomy of its skull using unreliable reference systems.展开更多
Blaptica dubia(Serville, 1838) and B. interior Hebard, 1921 were considered to be cryptic species. The characteristics originally proposed for their identification are not reliable.Thus the relationship between the tw...Blaptica dubia(Serville, 1838) and B. interior Hebard, 1921 were considered to be cryptic species. The characteristics originally proposed for their identification are not reliable.Thus the relationship between the two species should be re-considered. As a comparative approach and to analyze intraspecific variability, morphological and morphometric methods were performed. Traditional and new characters such as wing shape and pronotum contour were utilized. We found significant differences between both species(p <0.05) in the shape of the wing, but there was an overlap of values. We did not find differences in the body measurements or in the shape and size of the pronotum between the species. The variability gradient does not allow an accurate identification of species neither with the male genitalia or the pronotal macula.Based on the obtained results, B. interior Hebard 1921 is considered to be a junior synonym of B. dubia(Serville, 1838).展开更多
Most organ or tissue allografts with viable cells are sto red in solutions ex vivo for hours to seve ral days.Most allografts then require rapid host revascula rization upon transplantation to maintain donor-cell func...Most organ or tissue allografts with viable cells are sto red in solutions ex vivo for hours to seve ral days.Most allografts then require rapid host revascula rization upon transplantation to maintain donor-cell functions(e.g.,cardiac muscle contra ctions,hepatic secretions).In contrast,peripheral nerve allografts stored ex vivo do not require revascularization to act as scaffolds to guide outgrowth by host axons at 1-2 mm/d,likely aided by viable donor Schwann cells.Using current storage solutions and protocols,axons in all these donor orga n/tissue/nerve transplants are expected to rapidly become non-viable due to Wallerian degeneration within days.Therefore,ex vivo storage solutions have not been assessed for preserving normal axonal functions,i.e.,conducting action potentials or maintaining myelin sheaths.We hypothesized that most or all organ storage solutions would maintain axonal viability.We examined several common organ/tissue storage solutions(University of Wisconsin Cold Storage Solution,Normosol-R,Normal Saline,and La ctated Ringe rs) for axonal viability in rat sciatic nerves ex vivo as assessed by maintaining:(1) conduction of artificially-induced compound action potentials;and(2) axonal and myelin morphology in a novel assay method.The ten diffe rent storage solution conditions for peripheral nerves with viable axons(PNVAs) diffe red in their solution composition,osmolarity(250-318 mOsm),temperature(4℃ vs.25℃),and presence of calcium.Compound action potentials and axonal morphology in PNVAs were best maintained for up to 9 days ex vivo in calcium-free hypotonic diluted(250 mOsm) Normosol-R(dNR) at 4℃.Surprisingly,compound action potentials were maintained for only 1-2 days in UW and NS at 4℃,a much shorter duration than PNVAs maintained in 4℃ dNR(9 days) or even in 25℃ dNR(5 days).Viable axons in peripheral nerve allografts are critical for successful polyethylene glycol(PEG)-fusion of viable proximal and distal ends of host axons with viable donor axons to repair segmental-loss peripheral nerve injuries.PEG-fusion repair using PNVAs prevents Wallerian degeneration of many axons within and distal to the graft and results in excellent recovery of sensory/motor functions and voluntary behaviors within weeks.Such PEG-fused PNVAs,unlike all other types of conventional donor transplants,are immune-tolerated without tissue matching or immune suppression.Preserving axonal viability in sto red PNVAs would enable the establishment of PNVA tissue banks to address the current shortage of transplantable nerve grafts and the use of stored PEG-fused PNVAs to repair segmentalloss peripheral nerve injuries.Furthermore,PNVA storage solutions may enable the optimization of ex vivo storage solutions to maintain axons in other types of organ/tissue transplants.展开更多
Sexual dimorphism between males and females is a common pattern observed in the natural world and has become one of the main focuses of evolutionary biology.Amphibian head size and shape are important factors that may...Sexual dimorphism between males and females is a common pattern observed in the natural world and has become one of the main focuses of evolutionary biology.Amphibian head size and shape are important factors that may influence food acquisition,but knowledge about the sexual differences between amphibian head size and shape is relatively scant.Here,intersexual differences in the head size and shape of Rana kukunoris,which is a high-elevation frog from the Qinghai-Tibet Plateau,were investigated.Significant differences were found in the head shape but not the head size between sexes.A significant correlation was also observed between prey size and head size.However,these correlations disappeared when individual body size was controlled,suggesting that body size but not food size was the main factor resulting in intersexual differences in head size/shape.The results suggested that food competition between sexes did not result in sexual dimorphism of head shape among these frogs.展开更多
Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss cos...Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.展开更多
This study finds 1D, 2D and 3D morphometric parameters of the middle-west part of Kushtia district, Bangladesh to implement groundwater potential. For this purpose, the SRTM (DEM) data were used to compute different p...This study finds 1D, 2D and 3D morphometric parameters of the middle-west part of Kushtia district, Bangladesh to implement groundwater potential. For this purpose, the SRTM (DEM) data were used to compute different parameters in GIS environment. The values of 1D parameters like stream order, stream length and mean bifurcation ratio was calculated as 6, 1774.72 km and 2.08 respectively. The computed values of drainage density (0.01 - 23.06 km/km<sup>2</sup>), stream frequency (1 - 5.64 per km<sup>2</sup>), drainage texture (0.25 - 0.70 km/km<sup>4</sup>), length of overland flow (0.02 - 45.05 km<sup>2</sup>/km), constant of channel maintenance (0.04 - 90.04 km<sup>2</sup>/km), circularity ratio (0.39 - 0.84), form factor (0.35), elongation ratio (0.62), relief ratio (0.00 - 1.81) and ruggedness number (0.04 - 214.72) disclose the morphometrical conditions of the study area. The results revealed from this study on drainage morphometry can be a great assistance for understanding the hydro-geomorphological character of the area.展开更多
The purpose of this study is to demonstrate how modern technologies such as geographic information systems (GIS) and digital elevation models can help in the creation of a geographic database for the Wadi Wizr basin i...The purpose of this study is to demonstrate how modern technologies such as geographic information systems (GIS) and digital elevation models can help in the creation of a geographic database for the Wadi Wizr basin in Egypt’s Central Eastern Desert, in addition to examining and analysing the radioactive properties of various rocks. This was accomplished with the help of a digital elevation model (DEM) with a 30 metre accuracy and GIS software in 10.8 Arc Map. The RS-230 was also used to measure uranium and thorium concentrations. GIS softwares and digital elevation models have been shown to be more effective than the traditional method. This was demonstrated by the flexible and quick working method, the accuracy of the parameters used, and the results of the morphometric analysis of the basin river network. In addition to, the main drainage pattern from subtype to tree type, where the branching ratio was (1.59). This basin could also cause flooding. Similar studies, according to the results of this study, should make greater use of geographic information system technology and modern data sources. Wadi Wizr also has a radioactive anomaly, with uranium equivalent concentrations reaching 70 ppm in some fault parts.展开更多
文摘The morphological differences between two geographical maps can be highlighted by a polycentric distance cartogram resulting from a bidimensional regression.Beyond the communicational interest of the transformations thus produced,the method makes it possible to reveal the differences in structure and therefore constitutes a real research tool.However,bidimensional regression can only compare the shape of two maps.Since the 1990s,geometric morphometrics has revolutionized the morphological analysis of natural structures(and others).It has since been applied in many fields of research but not in cartography.This article describes the theoretical and methodological bases of a method combining bidimensional regression with a geometric morphometrics approach to compare the shape of several geographical maps.Geometric morphometrics and bidimensional regression indeed share common approaches of the statistical shape analysis like homologous landmarks and interpolation grids.However,there is no software in geometric morphometrics capable of directly reading geographical data,which would facilitate the work of cartographers accustomed to GIS software.That is why we present MapMorphy,a tool specifically developed for this task.An example on ancient maps illustrates the method.
基金Supported by the National Key Basic Research Program of China(973 Program)(No.2015CB453302)the NSFC-Shandong Joint Fund for Marine Science Research Centre(No.U1606404)the Aoshan Science and Technology Innovation Project(No.2015ASKJ02-04)
文摘T his study compared and evaluated the efficiency of two otolith shape descriptors(i.e., the elliptic Fourier transform(EFT) and discrete wavelet transform(DWT)) and morphometrics for stock discrimination. To accomplish this, sample fish from three stocks of yellow croaker L arimichthys polyactis along the Chinese coast(LDB stock from the Liaodong Bay of the Bohai Sea, JZB stock from the Jiaozhou Bay of the Yellow Sea and CJE stock from the Changjiang River estuary of the East China Sea) were used for otolith morphology analyses. The results showed that morphometrics produced an overall classification success rate of 70.8% in contrast with success rates of 80.0% or 82.0% obtained using EFT or DWT, respectively. This suggests that the two shape descriptors comparably discriminated among the stocks and performed more efficiently than morphometrics. During data adjustment and acquisition, some size variables were excluded from the subsequent discriminant analysis for stock discrimination because they were statistically "inef fective," which could reduce the efficiency of morphometrics and lead to relatively low overall classification success. Both EFT and DWT retain the contour coefficients and thus provide a detailed description of otolith shape, which could improve discriminatory efficiency compared with morphometrics.
基金supported by the Chinese Academy of Sciences(KZZD-EW-02,kzcx2-yw-153)the National Natural Science Foundation of China(Nos.41030209and41173051)
文摘As a more efficient quantitative method for morphological analysis, geometric morphometrics is applied to the flabellate fossils Flabellophyton including Flabellophyton lantianensis and Flabellophyton strigata from Neoproterozoic Ediacaran Lantian biota, South China. Both traditional morphometric analysis (including diverging angle, length, and width distribution) and geometric morphometric analysis [including superposition of normalized area analysis, non-metric multidimensional scaling (n-MDS), Bray-Curtis similarity cluster analysis (CLUSTER) and analysis of similarities (ANOSIM)[ were performed. The results indicate there are great interspecific morphological differences between F. lantianensis and F. strigata, in addition to some intraspecific variations within each species. Here we preliminarily suggest that the previously defined Flabellophyton should be subdivided into 2 genera at least: one marked by the dark transverse striated structure, and the other without. This recharacterization and reclassification work still needs further careful observation and comprehensive analysis with large number of flabeilate fossils combining morphology, structure, population, and community-ecology study.
基金supported by the National Natural Science Foundation of China (31470110, 31970399)China National GeneBank (CNGB)。
文摘Pikas(Lagomorpha: Ochotonidae) are small mouselike lagomorphs. To investigate their adaptation to different ecological environments during their dispersal from the Qinghai-Xizang(Tibet) Plateau(QTP), we collected 226 pikas and measured 20 morphological characteristics and recorded habitat information. We also sequenced the genome of 81specimens, representing 27 putative pika species.The genome-wide tree based on 4?090 coding genes identified five subgenera, i.e., Alienauroa, Conothoa,Lagotona, Ochotona, and Pika, consistent with morphometric data. Morphologically, Alienauroa and Ochotona had similar traits, including smaller size and earlier divergence time compared to other pikas.Consistently, the habitats of Alienauroa and Ochotona differed from those of the remaining subgenera. Phylogenetic signal analysis detected 83 genes significantly related to morphological characteristics, including several visual and hearingrelated genes. Analysis of shared amino acid substitutions and positively selected genes(PSGs) in Alienauroa and Ochotona identified two genes, i.e.,mitochondrial function-related TSFM(p.Q155E) and low-light visual sensitivity-related PROM1(p.H419Y).Functional experiments demonstrated that TSFM-155E significantly enhanced mitochondrial function compared to TSFM-155Q in other pikas, and PROM1-419Y decreased the modeling of dynamic intracellular chloride efflux upon calcium uptake. Alienauroa and Ochotona individuals mostly inhabit different environments(e.g., subtropical forests) than other pikas, suggesting that a shift from the larger ancestral type and changes in sensory acuity and energy enhancement may have been required in their new environments. This study increases our understanding of the evolutionary history of pikas.
基金The University of Malaya,Kuala Lumpur,Malaysia through UMRG Grant under contract No.RG104-11SUSUMRP Grant under contract No.RU006E-2014the postgraduate sponsorship from the Ministry of Higher Education(MyBrain scholarship programme)
文摘The morphology of seven specimens of Chrysaora chinensis(Scyphomedusae,Semaestomae)obtained from four sites off the coast of Peninsular Malaysia was examined.Morphological characteristics of C.chinensis that encompasses structures such as the bell,tentacles,oral arms,stomach,manubrium,radial canals and gonads were described in detail.A total of 107 specimens that represented C.chinensis populations of four coastal areas of Peninsular Malaysia(East-Central,East-North,West-Central,and West-North)were also analysed for shape variation using geometric morphometric analysis.Procrustes superimposition,Principal Component Analysis(PCA)and Canonical Variate Analysis(CVA)were applied to the images of gastrovascular pouches of C.chinensis to extract the shape information.Independent contrasts were used for comparisons between shapes.There were no significant differences in shape variation between all the specimens based on the PCA results.However,CVA results showed shape variations between specimens taken from the four areas of Peninsular Malaysia,especially with higher magnitudes of Mahalanobis distances between the east and west coast areas,including between East-Central and East-North,but lower magnitudes were detected between the West-Central and West-North.
基金supported by grants to Prof.Dong-Jin Lee from the Korean Research Foundation
文摘The Upper Ordovician Xiazhen Formation in the Jiangshan-Changshan-Yushan (JCY) triangle area on the Zhejiang-Jiangxi provincial border, South China, is composed of a mixed carbonate-siliciclastic sequence representing various shallow-water platform environments. Highly diversified and abundant heliolitid coral faunas are recognized in the formation and occur over time and space in certain stratigraphic horizons and various lithofacies. Heliolites has been studied using multivariate morphometric analysis applied to differentiate species and evaluate intraspecific and interspecific variations. Ten morphological characters quantified by examination and measurement from transverse and longitudinal thin sections and statistically tested allowed selection of effective characters to discriminate species. Results of frequency histograms, correlation analysis and principle component analysis indicated that certain characters would be suitable for cluster analysis, which were performed on principle component score matrices obtained from the raw data set coordinated with coralla by all those characters. Five major clusters at a relative distance of five on the resulting dendrogram of Heliolites are regarded as morphospecies thus making valid taxa: Heliolites tashanensis Lin and Chow, 1977; Heliolites caracolica (Lin and Chow, 1977); Heliolites columella (Lin and Chow, 1977); Heliolites waicunensis Lin and Chow, 1977; and H. sinensis irregularis Lin and Chow, 1977. The discrimination of these morphospecies by the cluster analysis is verified by discriminant analyses and descriptive statistics.
基金Supported by This work was supported by the Department of Defense(DoD)BCRP,No.BC190820the National Cancer Institute(NCI)at the National Institutes of Health(NIH),No.R01CA184476+1 种基金MCIN/AEI/10.13039/501100011039,No.PID2020-118527RB-I00,and No.PDC2021-121735-I00the“European Union Next Generation EU/PRTR.”the Regional Government of Castile and León,No.CSI144P20.Lawrence Berkeley National Laboratory(LBNL)is a multi-program national laboratory operated by the University of California for the DOE under contract DE AC02-05CH11231.
文摘BACKGROUND The development of precision medicine is essential for personalized treatment and improved clinical outcome,whereas biomarkers are critical for the success of precision therapies.AIM To investigate whether iCEMIGE(integration of CEll-morphometrics,MIcro-biome,and GEne biomarker signatures)improves risk stratification of breast cancer(BC)patients.METHODS We used our recently developed machine learning technique to identify cellular morphometric biomarkers(CMBs)from the whole histological slide images in The Cancer Genome Atlas(TCGA)breast cancer(TCGA-BRCA)cohort.Multivariate Cox regression was used to assess whether cell-morphometrics prognosis score(CMPS)and our previously reported 12-gene expression prognosis score(GEPS)and 15-microbe abundance prognosis score(MAPS)were independent prognostic factors.iCEMIGE was built upon the sparse representation learning technique.The iCEMIGE scoring model performance was measured by the area under the receiver operating characteristic curve compared to CMPS,GEPS,or MAPS alone.Nomogram models were created to predict overall survival(OS)and progress-free survival(PFS)rates at 5-and 10-year in the TCGA-BRCA cohort.RESULTS We identified 39 CMBs that were used to create a CMPS system in BCs.CMPS,GEPS,and MAPS were found to be significantly independently associated with OS.We then established an iCEMIGE scoring system for risk stratification of BC patients.The iGEMIGE score has a significant prognostic value for OS and PFS independent of clinical factors(age,stage,and estrogen and progesterone receptor status)and PAM50-based molecular subtype.Importantly,the iCEMIGE score significantly increased the power to predict OS and PFS compared to CMPS,GEPS,or MAPS alone.CONCLUSION Our study demonstrates a novel and generic artificial intelligence framework for multimodal data integration toward improving prognosis risk stratification of BC patients,which can be extended to other types of cancer.
文摘In order to incorporate the knowledge of two species of wild doves and compare the results of both, we assessed morphometrics (body weight, bill, tarsus, tail, wing, head and culmen length) and body condition index (using weigh, wing, tail and tarsus length) of Eurasian Collared-Dove Streptopelia decaocto and Mourning Dove Zenaida macroura (Aves: Columbidae) based on 40 specimens of each species collected during fall-winter 2013 and spring-summer 2014 in the municipality of Durango, Durango, Mexico. We found that body condition index was higher during fallwinter for both species. We also found size dimorphism. Males of Eurasian Collared-Dove were larger than females in head length (p = 0.002) and tail length (p = 0.05) but smaller in culmen length. Female Mourning Doves had a higher body condition index compared to males (p = 0.02) during both seasons. As expected, Eurasian Collared-Dove was larger in all measurements than Mourning Dove (p > 0.05) but tail length (p = 0.12).
基金supported by the National Natural Science Foundation of China(31560604,31160433)the Guangxi Natural Science Foundation(2015GXNSFAA139071)
文摘The morphological characteristics of the hind wing venation of tetrigids were analyzed on the basis of morphometric measurement, with 20 species and 18 different variables selected for this study. Results show that three principal components have a higher load at the length between the starting point of the costal vein and the tip of the fourth anal vein, between the tip of the costal vein and the tip of the third anal vein, and between the tip of the costal vein and the tip of the eleventh anal vein. There exists a contrast between wing length and width.
文摘Morphometrics has been pursued by graphical and computational means since the European Renaissance, drawing on core geometric principles first discovered in China and Classical Greece. Through the late 1800s, two distinct approaches to such analyses were pursued: a deformationist approach, epitomized by D'Arcy Thompson's graphical trans-formation grids and the statistical approach popularized by Francis Galton, Karl Pearson, and Julian Huxley in which Cartesian spaces were employed to summarize patterns of variation in size and/or shape variables. Unification of these approaches was an off-stated goal throughout the 20th century, but proved elusive until the mid-1980s when David Kendall, Fred Bookstein, and Colin Goodall proposed a radically new way of understanding form -- as the locations of configurations of landmarks on the surfaces of a nested series of hyperdimensional manifolds. Once this new mathematics of form was understood development of basic concepts, procedures, graphical tools, and statistical tests followed quickly such that the core of the long-hoped for synthesis took less than a decade to achieve. The result-- geometric morphometrics -- continues to develop into an ever-more extensive toolkit that can be used by researchers to describe and understand a wide range of problems involving the characterization of morphological similarities and differences in all of their many and varied contexts. In particular, the new approaches involving the direct analysis of image pixels and new tools such as machine learning and artificial intelligence are set to reinvigorate (and possibly to revolutionize) the field once again.
基金supported by the National Natural Science Foundation of China(31672345)Research Equipment Development Project of Chinese Academy of Sciences(YZ201509)
文摘Although there were many ancient Chinese mathematicians contributed a lot on geometry, Geometric morphometrics (GM) in modern concept was not firstly proposed by Chinese. The super capability of geometric morphometries in scientific computing and problem solving has gained a lot of attentions in the world. Until early of 21 centuries, geometric morphometries was introduced into China. Since then, GM was rapidly applied in many research fields. However, it is a pity that GM is still not well-known in China as many works are published out of China. Thus, the special issue "Geometric morphometrics: Current shape and future directions" is organized. The present issue presents a series of contributions in this scientific field. In future, there will be many considerable new developing fields on GM needed to pay more attentions, for instances, 3D geometric morphometrics, 4D analysis, visualization of amber, new machine developing, new software developing, automatic identification system, etc. Once these technical bottle-necks on 3D data collecting and merging geometric morphometric data from multiple characters could be solved, the automatic identification system and other fields based on Big Data would come true.
基金produced from the responsible author's master's thesis titled“Periglacial geomorphology of Mount Honaz(Denizli)”,prepared at BilecikŞeyh Edebali University,Social Sciences Institute in 2019.
文摘The main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic factors.Mud circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of Mount Honaz.Pearson's correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).To explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and analysed.Periglacial landforms,which continue to develop on the summits of Mount Honaz today,have been evaluated with present climate data.Analysis of soil samples indicates a notable impact of parent material on the genesis of periglacial landforms.The high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil properties.Furthermore,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.
基金This research was supported by a Graduate Student Research Grant from Rackham Graduate School and an N.Gary Lane Award from the Paleontological Society to B.W.
文摘The mammalian family Bovidae has been widely studied in ecomorphological research,with important applications to paleoecological and paleohabitat reconstructions.Most studies of bovid craniomandibular features in relation to diet have used linear measurements.In this study,we conduct landmark-based geometric-morphometric analyses to evaluate whether different dietary groups can be distinguished by mandibular morphology.Our analysis includes data for 100 species of extant bovids,covering all bovid tribes and 2 dietary classifications.For the first classification with 3 feeding categories,we found that browsers(including frugivores),mixed feeders,and grazers are moderately well separated using mandibular shape.A finer dietary classification(frugivore,browser,browser-grazer intermediate,generalist,variable grazer,and obligate grazer)proved to be more useful for differentiating dietary extremes(frugivores and obligate grazers)but performed equally or less well for other groups.Notably,frugivorous bovids,which belong in tribe Cephalophini,have a distinct mandibular shape that is readily distinguished from all other dietary groups,yielding a 100%correct classification rate from jackknife cross-validation.The main differences in mandibular shape found among dietary groups are related to the functional needs of species during forage prehension and mastication.Compared with browsers,both frugivores and grazers have mandibles that are adapted for higher biomechanical demand of chewing.Additionally,frugivore mandibles are adapted for selective cropping.Our results call for more work on the feeding ecology and functional morphology of frugivores and offer an approach for reconstructing the diet of extinct bovids.
基金financial supported by the Spanish MINECO,Project CGL-2013-42643
文摘The scope of shape analysis based on geometric morphometrics has evolved into underscoring complex patterns of multidimensional shape change with multivariate statistical modelling (e.g., allometry, morphological integration, etc.). Such breakthrough was made possible because the method relies on a consistent comparative reference system to compare shapes, the latter which is computed using the Cartesian coordinates of homologous landmarks. It has been shown elsewhere that traditional comparative reference systems based on anatomy, and oriented in stereotyped postures, such as the Frankfurt plane at rest, the Lateral Semicircular Canal when the animal is in alert, or the cranial floor when the animal is flying, are all inconsistent for anatomical comparisons. They vary too much and unpredictably across species. An extraordinary example of the problems that can arise in descriptive and comparative anatomy when using such reference systems is the traditional interpretation of the head of the Woodcock. Anywhere in literature it is written that the eyes of this gamebird are oriented backwards to protect itself from predators. Here, using geometric morphometrics it is demonstrated that the woodcock's skull is highly transformed, yet following a normal trend among birds. In turn, using GM it is demonstrated that the collective wisdom about this oddity is simply the result of interpreting the anatomy of its skull using unreliable reference systems.
基金funded by the Departamento de Biodiversidad y Biología Experimental,Facultad de Ciencias Exactas y Naturales,Universidad de Buenos AiresCentro Nacional de Diagnóstico e Investigación en Endemo-Epidemias,Administración Nacional de Laboratorios e Institutos de Salud "Dr.Carlos G.Malbrán"
文摘Blaptica dubia(Serville, 1838) and B. interior Hebard, 1921 were considered to be cryptic species. The characteristics originally proposed for their identification are not reliable.Thus the relationship between the two species should be re-considered. As a comparative approach and to analyze intraspecific variability, morphological and morphometric methods were performed. Traditional and new characters such as wing shape and pronotum contour were utilized. We found significant differences between both species(p <0.05) in the shape of the wing, but there was an overlap of values. We did not find differences in the body measurements or in the shape and size of the pronotum between the species. The variability gradient does not allow an accurate identification of species neither with the male genitalia or the pronotal macula.Based on the obtained results, B. interior Hebard 1921 is considered to be a junior synonym of B. dubia(Serville, 1838).
基金supported by grants from the Lone Star Paralysis Foundation and NIH R01NS081063 to GDBDepartment of Defense award W81XWH-19-2-0054 (to GDB)。
文摘Most organ or tissue allografts with viable cells are sto red in solutions ex vivo for hours to seve ral days.Most allografts then require rapid host revascula rization upon transplantation to maintain donor-cell functions(e.g.,cardiac muscle contra ctions,hepatic secretions).In contrast,peripheral nerve allografts stored ex vivo do not require revascularization to act as scaffolds to guide outgrowth by host axons at 1-2 mm/d,likely aided by viable donor Schwann cells.Using current storage solutions and protocols,axons in all these donor orga n/tissue/nerve transplants are expected to rapidly become non-viable due to Wallerian degeneration within days.Therefore,ex vivo storage solutions have not been assessed for preserving normal axonal functions,i.e.,conducting action potentials or maintaining myelin sheaths.We hypothesized that most or all organ storage solutions would maintain axonal viability.We examined several common organ/tissue storage solutions(University of Wisconsin Cold Storage Solution,Normosol-R,Normal Saline,and La ctated Ringe rs) for axonal viability in rat sciatic nerves ex vivo as assessed by maintaining:(1) conduction of artificially-induced compound action potentials;and(2) axonal and myelin morphology in a novel assay method.The ten diffe rent storage solution conditions for peripheral nerves with viable axons(PNVAs) diffe red in their solution composition,osmolarity(250-318 mOsm),temperature(4℃ vs.25℃),and presence of calcium.Compound action potentials and axonal morphology in PNVAs were best maintained for up to 9 days ex vivo in calcium-free hypotonic diluted(250 mOsm) Normosol-R(dNR) at 4℃.Surprisingly,compound action potentials were maintained for only 1-2 days in UW and NS at 4℃,a much shorter duration than PNVAs maintained in 4℃ dNR(9 days) or even in 25℃ dNR(5 days).Viable axons in peripheral nerve allografts are critical for successful polyethylene glycol(PEG)-fusion of viable proximal and distal ends of host axons with viable donor axons to repair segmental-loss peripheral nerve injuries.PEG-fusion repair using PNVAs prevents Wallerian degeneration of many axons within and distal to the graft and results in excellent recovery of sensory/motor functions and voluntary behaviors within weeks.Such PEG-fused PNVAs,unlike all other types of conventional donor transplants,are immune-tolerated without tissue matching or immune suppression.Preserving axonal viability in sto red PNVAs would enable the establishment of PNVA tissue banks to address the current shortage of transplantable nerve grafts and the use of stored PEG-fused PNVAs to repair segmentalloss peripheral nerve injuries.Furthermore,PNVA storage solutions may enable the optimization of ex vivo storage solutions to maintain axons in other types of organ/tissue transplants.
基金support from the National Natural Science Foundation of China(grant no.32270457)The authors confirmed that this study based on the The Animal Ethics Committee at Anhui University permitted this experiments(IACUC(AHU)-2022-007).
文摘Sexual dimorphism between males and females is a common pattern observed in the natural world and has become one of the main focuses of evolutionary biology.Amphibian head size and shape are important factors that may influence food acquisition,but knowledge about the sexual differences between amphibian head size and shape is relatively scant.Here,intersexual differences in the head size and shape of Rana kukunoris,which is a high-elevation frog from the Qinghai-Tibet Plateau,were investigated.Significant differences were found in the head shape but not the head size between sexes.A significant correlation was also observed between prey size and head size.However,these correlations disappeared when individual body size was controlled,suggesting that body size but not food size was the main factor resulting in intersexual differences in head size/shape.The results suggested that food competition between sexes did not result in sexual dimorphism of head shape among these frogs.
文摘Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.
文摘This study finds 1D, 2D and 3D morphometric parameters of the middle-west part of Kushtia district, Bangladesh to implement groundwater potential. For this purpose, the SRTM (DEM) data were used to compute different parameters in GIS environment. The values of 1D parameters like stream order, stream length and mean bifurcation ratio was calculated as 6, 1774.72 km and 2.08 respectively. The computed values of drainage density (0.01 - 23.06 km/km<sup>2</sup>), stream frequency (1 - 5.64 per km<sup>2</sup>), drainage texture (0.25 - 0.70 km/km<sup>4</sup>), length of overland flow (0.02 - 45.05 km<sup>2</sup>/km), constant of channel maintenance (0.04 - 90.04 km<sup>2</sup>/km), circularity ratio (0.39 - 0.84), form factor (0.35), elongation ratio (0.62), relief ratio (0.00 - 1.81) and ruggedness number (0.04 - 214.72) disclose the morphometrical conditions of the study area. The results revealed from this study on drainage morphometry can be a great assistance for understanding the hydro-geomorphological character of the area.
文摘The purpose of this study is to demonstrate how modern technologies such as geographic information systems (GIS) and digital elevation models can help in the creation of a geographic database for the Wadi Wizr basin in Egypt’s Central Eastern Desert, in addition to examining and analysing the radioactive properties of various rocks. This was accomplished with the help of a digital elevation model (DEM) with a 30 metre accuracy and GIS software in 10.8 Arc Map. The RS-230 was also used to measure uranium and thorium concentrations. GIS softwares and digital elevation models have been shown to be more effective than the traditional method. This was demonstrated by the flexible and quick working method, the accuracy of the parameters used, and the results of the morphometric analysis of the basin river network. In addition to, the main drainage pattern from subtype to tree type, where the branching ratio was (1.59). This basin could also cause flooding. Similar studies, according to the results of this study, should make greater use of geographic information system technology and modern data sources. Wadi Wizr also has a radioactive anomaly, with uranium equivalent concentrations reaching 70 ppm in some fault parts.