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
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
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
To compare the application of traditional morphometric methods(TMMs)and geometric morphometric methods(GMMs)in the study of intraspecific leaf morphological characters of Quercus dentata,fifteen linear measurement ind...To compare the application of traditional morphometric methods(TMMs)and geometric morphometric methods(GMMs)in the study of intraspecific leaf morphological characters of Quercus dentata,fifteen linear measurement indices and thirteen landmarks of leaves were used to study leaf morphology of three provenances(H1,H2,and H3).In TMMs,principal component analysis(PCA)showed that leaf size–related indices played an important role in population classification.Partial least square(PLS)analysis showed that the main morphological characters affecting leaf size were the average depth of the lobes and the length–width ratios.However,the important indices to distinguish the provenances were circularity,leaf width,and length–width ratio.The results of discriminant analysis(DA)showed that 74.0%of H1,68.0%of H2,and 74.0%of H3 were correctly classified.Cluster analysis showed that the Mahalanobis distances between H1 and H2,H1 and H3,and H2 and H3 were 4.3761,11.4629,and 10.2067,respectively.In GMMs,PCA based on symmetrical components showed that the difference in leaf morphology was mainly due to the changing trend of the leaf apex and base,petiole length,and degree of leaf cracking.PLS analysis showed that there was a significant covariation between the leaf symmetrical components and size:as the leaf enlarged,the widest part gradually moved up,and the shape changed from nearly oval to lanceolate.DA results showed that 86.0%and 78.0%of H1 and H2,70.0%and 80.0%of H1 and H3,and 82.0%and 76.0%of H2 and H3 were correctly classified.Canonical variate analysis results showed that the Mahalanobis distances between H1 and H2,H1 and H3,and H2 and H3 were 1.7238,1.5380,and 1.6329,respectively.Both GMMs and TMMs showed significant differences in morphology among the three Q.dentata provenances,but GMMs had higher classification accuracy and could provide more information about leaf shape,whereas TMMs could provide more information about leaf size.Based on our results,GMMs are promising in the study of leaf morphological variation within Q.dentata provenances.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
Objective: To study the relationship between the ser- um levels of hyaluronic acid (HA), procollagen type Ⅲ (PCⅢ), collagen type Ⅳ (CIV) and the histologi- cal degree of hepatic fibrosis evaluated by image analysis...Objective: To study the relationship between the ser- um levels of hyaluronic acid (HA), procollagen type Ⅲ (PCⅢ), collagen type Ⅳ (CIV) and the histologi- cal degree of hepatic fibrosis evaluated by image analysis, and the clinical significance of serum HA, PC Ⅲ, C Ⅳ in the diagnosis of hepatic fibrosis in pa- tients with chronic viral hepatitis. Methods: The concentrations of serum HA, PC Ⅲ, C Ⅳ in 151 patients with chronic viral hepatitis were measured by radioimmunoassay. Liver biopsies were performed in all the patients. Histological sections of 4 μm thickness were stained with Masson's trichrome for fibrosis assessment. Morphometric quantitative measurements for hepatic fibrosis assessment in the 4 μm sections were performed using a fully automated image analysis system. Serum levels of HA, PC Ⅲ, and C Ⅳ were analyzed at different stages of liver pa- thology and compared with the morphometric quanti- tative measurements of hepatic fibrosis. Results: The serum levels of HA, PC Ⅲ, C Ⅳ all ele- vated gradually with the progression of the disease, and all reached the highest in patients with liver cir- rhosis. There was a significant difference in the levels of these 3 components between liver cirrhosis group and the other groups (P<0.05). They all increased steadily with the histological stages of hepatic fibrosis, and reached the highest levels in stage Ⅳ. The serum levels of HA, PC Ⅲ, C Ⅳ were all positive- ly correlated with the histological stages of liver sec- tions and the morphometric measurement (P< 0.001). The coefficients with stages were 0.694, 0.493, 0.552 (P<0.001), respectively and with sur- face density of total collagen on liver biopsy sections by image analysis were 0. 715, 0. 595, 0. 573 (P< 0.001), respectively. Conclusion: The serum levels of HA, PC Ⅲ, C Ⅳ were in consistent with the degree of hepatic fibrosis, and the determination of these marks is valuable for detecting hepatic fibrosis.展开更多
Remote sensing and GIS techniques were employed for prioritization of the Zerqa River watershed. Forty-three 4th order sub-watersheds were prioritized based on morphometric and Principal Component Analysis (PCA), in o...Remote sensing and GIS techniques were employed for prioritization of the Zerqa River watershed. Forty-three 4th order sub-watersheds were prioritized based on morphometric and Principal Component Analysis (PCA), in order to examine the effectiveness of morphometric parameters in watershed prioritization. A comparison has been carried out between the results achieved through applying the two methods of analysis (morphometric and PCA). Afterwards, suitable measures are proposed for soil and water conservation. Topo sheets and ASTER DEM have been employed to demarcate the 43 sub-watersheds, to extract the drainage networks, and to compile the required thematic maps such as slope categories and elevation. LANDSAT 8 image (April-2015) is employed to generate land use/cover maps using ENVI (v 5.1) software. The soil map of the watershed has been digitized using Arc GIS software. Prioritization of the 43 sub-watersheds was performed using ten linear and shape parameters, and three parameters which are highly correlated with components 1 and 2. Subsequently, different sub-watersheds were prioritized by ascribing ranks based on the calculated compound parameters (Cp) using the two approaches. Comparison of the results revealed that prioritization of watersheds based on morphometric analysis is more consistent and serves for better decision making in conservation planning as compared with the PCA approach. The recommended soil conservation measures are prescribed in accordance with the specified priority, in order to avoid undesirable effects on land and environment. Sub-watersheds classified under high priority class are subjected to high erosion risk, thus, creating an urgent need for applying soil and water conservation measures. It is expected that decision makers will pay sufficient attention to the present results/information, activate programs encouraging soil conservation, integrated watershed management, and will continue working on the afforestation of the government-owned sloping lands. Such a viable approach can be applied at different parts of the rainfed highland areas to minimize soil erosion loss, and to increase infiltration and soil moisture in the soil profile, thus, reducing the impact of recurrent droughts and the possibility of flooding hazards.展开更多
Commercial farming of anuran species that are declining in the wild raises a need to discriminate wild from farmed frogs.We hypothesized wild frogs might have extended hindlimbs due to greater frequency or intensity o...Commercial farming of anuran species that are declining in the wild raises a need to discriminate wild from farmed frogs.We hypothesized wild frogs might have extended hindlimbs due to greater frequency or intensity of jumping relative to farmed frogs,highlighting a morphometric approach to discrimination of wild from farmed frogs using hindlimb length.In the present study,Dybowski's frog(Rana dybowskii) was used to test this hypothesis.We measured body mass(Mb) and hindlimb length(Lh) of 2-year old farmed frogs and wild frogs aged 2 to 5 years.Dybowski's frog demonstrated significant dimorphism in Mb and Lh.Mb was significantly greater among farmed 2-year old frogs in both sexes(p=0.000),while only among females was Lh significantly greater for wild frogs(p=0.000).Lh/Mb was used as an index for origin discrimination to eliminate the influence of Mb due to variation of husbandry conditions among farms.Mean Lh/Mb for farmed frogs was significantly lower than for wild frogs(p=0.000) in the 2-year old age class.Discrimination correctly classified 84.4% of farmed and 96.3% of wild male frogs.Among females,92.9% of farmed frogs and 90.1% wild frogs were correctly classified.The overall correctness of classification was 92.1% and 90.8% for males and females,respectively.However,Lh/Mb revealed variation with age,resulting in reduced discriminative power for frogs ≥3 years old.We introduced a coefficient Ce to adjust the Lh/Mb of frogs ≥3 years to the level equivalent to 2-year frogs.The adjustment achieved 89.5% for overall correctness of origin for wild males and 92.4% for wild females ≥3 years old.These results show that Lh/Mb is an effective index to discriminate wild from farmed Dybowski's frog.Since the physical demands of jumping are common among anurans,this index is also potentially applicable to other anuran species.展开更多
Allactaginae is a subfamily of dipodids consisting of four-and five-toed jerboas(Allactaga, Allactodipus,Orientallactaga, Pygeretmus, Scarturus) found in open habitats of Asia and North Africa. Recent molecular phylog...Allactaginae is a subfamily of dipodids consisting of four-and five-toed jerboas(Allactaga, Allactodipus,Orientallactaga, Pygeretmus, Scarturus) found in open habitats of Asia and North Africa. Recent molecular phylogenies have upended our understanding of this group's systematics across taxonomic scales. Here, I used cranial geometric morphometrics to examine variation across 219 specimens of 14 allactagine species(Allactaga major, A. severtzovi, Orientallactaga balikunica, O.bullata, O. sibirica, Pygeretmus platyurus, P. pumilio,P. shitkovi, Scarturus aralychensis, S. euphraticus,S. hotsoni, S. indicus, S. tetradactylus, S. williamsi)in light of their revised taxonomy. Results showed no significant sexual size or shape dimorphism. Species significantly differed in cranial size and shape both overall and as species pairs. Species identity had a strong effect on both cranial size and shape. Only a small part of cranial shape variation was allometric,with no evidence of unique species allometries, and most specimens fit closely to the common allometric regression vector. Allactaga was the largest,followed by Orientallactaga, Scarturus, and finally Pygeretmus. Principal component 1(PC1) separated O. bullata+O. balikunica+S. hotsoni(with inflated bullae along with reduced zygomatic arches and rostra) from A. major+A. severtzovi+O. sibirica(with converse patterns), while PC2 differentiated Orientallactaga(with enlarged cranial bases and rostra along with reduced zygomatic arches and foramina magna) from Scarturus+Pygeretmus(with the opposite patterns). Clustering based on the unweighted pair group method with arithmetic mean(UPGMA) contained the four genera, but S. hotsoni clustered with O. bullata+O. balikunica and O.sibirica clustered with A. major+A. severtzovi, likely due to convergence and allometry, respectively.展开更多
Morphometric analysis is an indispensable tool for hydrological investigation that involves the development and management of drainage basin. This study characterizes the micro watersheds in the Palar sub-watershed us...Morphometric analysis is an indispensable tool for hydrological investigation that involves the development and management of drainage basin. This study characterizes the micro watersheds in the Palar sub-watershed using morphometric analysis and assesses its risk by land use and land cover features in a particular micro watershed. Palar sub-watershed is divided into 6 micro watersheds for prioritization based on morphometric and land use analysis. Several morphometric parameters (linear, shape and relief) are determined from the drainage map; ranks are assigned based on their capacity to induce erodability and degradation. Final ranking is based on the composite index calculated from the sum of the ranks of each morphometric parameter. Morphometric analysis reveals micro watersheds 5 and 6 as most susceptible and 2 and 3 as low susceptible. Land use is mapped using IRS ID LISS III satellite data. The risk in terms of watershed degradation involved to each micro watershed is based on the ranks of each land use feature, obtained from a similar composite index as that of morphometric analysis. Land use analysis shows that micro watersheds 2 and 4 fall under high priority category while 5 and 6 under low priority category. Integration of the morphometric and land use analysis shows that only microwatershed 1 falls under the same category in both analyses. Control measures are suggested to contain degradation depending on its specific land use pattern and morphometric features. This study ean be used to prepare a comprehensive watershed plan for the development or for planning resource conservation strategies, by integrating land use features with the drainage characteristics of the region, in particular for a hill ecosystem as the prioritization is at micro level.展开更多
Extreme and prolonged rainfall in the Tunka Ridge caused several debris flows in the vicinity of the Arshan village(Siberia, Russia) on June 28, 2014. These debris flows, in spite of similar geological conditions, had...Extreme and prolonged rainfall in the Tunka Ridge caused several debris flows in the vicinity of the Arshan village(Siberia, Russia) on June 28, 2014. These debris flows, in spite of similar geological conditions, had different velocity, peak discharge and alluvial fan volume values. The flow velocity was from 3.5 m/s to 19.6 m/s, the peak discharge ranged from 63 m3/s to 13566 m3/s, and the alluvial fan volume varied from 4.13×103 to 8.45×105 m3. Such a great range of values is due to the morphometric parameters of the debris flow basins. The article deals with the influence of morphometric parameters of debris flow basins, such as the basin area, the average slope, Melton ratio, relief ratio on the debris flow velocity, peak discharge and volume of alluvial fans. In this debris flow event the average values of slope angle and total basin relief of the debris flow basins did not affect the values of debris flow velocity, peak discharge and alluvial fan volume. The highest correlations were observed with the debris flow basin area that was connected with the water inflow volume into the debris flow basins during the rainfall. The unequal water distribution among debris flow basins also had an impact on the debris flow velocity, peak discharge and volume of alluvial fans.展开更多
Analysis of 3D measurements of 13 landmarks on 72 Yuanmou Hominoid lower molars and some comparative samples, using Euclidean Distance Matrix Analysis (EDMA), show that the 3D morphometric features of Yuanmou Homi noi...Analysis of 3D measurements of 13 landmarks on 72 Yuanmou Hominoid lower molars and some comparative samples, using Euclidean Distance Matrix Analysis (EDMA), show that the 3D morphometric features of Yuanmou Homi noid lower molars largely resemble those of Lufengpithecus. Compared with extant great apes and humans, both Yuanmou Hominoid and Lufengpithecus differ markedly from humans, whereas they show much resemblance to apes. The two Chinese hominoids and extant great apes are different from humans in many of the same ways. Moreover, 3D morphometric features of Yuanmou Hominoid lower molars differ from those of each of the three extant great apes in similar ways. Of the three, the orangutan is the closest match to Yuanmou Hominoid in tooth morphology. However, the exact implications of these similarities and differences remain to be determined.展开更多
The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate...The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate new varieties from Indica and Japonica cultivars. Morphometric parameters of the grains were evaluated by image analysis. Flours were prepared from the whole rice grains and physicochemical, thermal and rheological properties, X-ray diffraction pattern and evaluation of color using the CIELAB system were assessed. The hybrids lines showed long (061, 611, 721), medium (719 and 720) and short (067) grains. The rice samples presented lipids (2.6% - 3.2%), protein (11% - 15%), total dietary fiber (8.4% - 10.2%), total starch (65% - 74%) and apparent amylose (5% - 32%) contents. Gelatinization temperature (Tp) was found in the range of 66.1℃ - 79.4℃ with enthalpy (ΔH) value between 3.4 - 8.1 J/g. The retrogradation parameters (temperature and ΔH) were lower than those for gelatinization in all samples. The rice samples presented A-type X-ray diffraction pattern. Rice pastes showed a non-Newtonian behavior and the brightness (L*) characterize the color of the samples. Hybrid rice grains presented morphometric properties more similar to Japonica than Indica variety. Rice hybrid had higher protein content than Indica variety. Apparent amylose, viscosity and gelatinization temperature varied significantly among hybrids and varieties.展开更多
Shrimps of genus Artemia are the inhabitants of continental and marine waters with salinity of 70 to 350 g/l and above.Artemia is able to survive in the conditions in which other animals cannot exist.This is due to ad...Shrimps of genus Artemia are the inhabitants of continental and marine waters with salinity of 70 to 350 g/l and above.Artemia is able to survive in the conditions in which other animals cannot exist.This is due to adaptations:effective osmoregulation system,the ability to synthesize of respiratory pigment(hemoglobin)and diapauses cysts(Litvinenko at.al.,2009).Cysts of this展开更多
The Douala-Buea Region(DBR;4°-5°N,9°-10°30’E),a portion of the southern Cameroon passive margin,developed on the Proterozoic granito-gneissic basement and the Cretaceous to Recent volcanosedimenta...The Douala-Buea Region(DBR;4°-5°N,9°-10°30’E),a portion of the southern Cameroon passive margin,developed on the Proterozoic granito-gneissic basement and the Cretaceous to Recent volcanosedimentary cover,was explored in order to evaluate the lithology and tectonics controls on its landscape usingthequalitativeandquantitative geomorphological analyses based on 30 m resolution Digital Elevation Models(DEM)and field evidences.This area displays an uneven and complex landscape differentiated into four morphological units:Douala,Nkondjock,Kumba and Buea Units.The Douala Unit corresponds to the Coastal Plain and is extended on the Douala-Kribi/Camposedimentarybasin.The Nkondjock Unit represents a middle plateau developed on a Proterozoic granito-gneissic basement.The Kumba Unit matches with the southernmost volcanic Western Cameroon High Plateau.The Buea Unit corresponds to the Mount Cameroon stratovolcano.The relief analysis through mountain-front sinuosity(Smf,1.19–1.43)and relative relief ratio(Rr,0.10–2.31)vary from one unit to another.The drainage network analysis including drainage patterns,stepped longitudinalriverprofiles,theassociated morphometric indexes,notably the concavity index(IC,0.56–0.88),deviation(D,267–2912 m),basin asymmetry factor(A_(F),6.37–42.12),hypsometric integral(HI,0.10–0.29),valley floor width to valley height ratio(V_(f),0.36–2.75),elongation ratio(R_(e),0.30–0.50),watershed slope(S,6.88–88.88)and stream length gradient index(SL,0–3332)vary from one basin to another too.These results also show the heterogeneous and uneven DBR landscape controlled by its lithology and active tectonics.The drainage system reveals concave to concavo-convex longitudinal river profile shapes with knick points,asymmetric basins,and fault reactivations,and highlights the tectonics activity that used to occur through the time and their control on the morphology.Together,they document the lithostructural controls on the DBR landscape evolution,extendable in the whole SW Cameroon margin.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
Background:The Elegant Pitta(Pitta elegans)complex displays a remarkable diversity of morphological and bioacoustic traits across five taxa currently recognized as subspecies.They differ in plumage characteristics(suc...Background:The Elegant Pitta(Pitta elegans)complex displays a remarkable diversity of morphological and bioacoustic traits across five taxa currently recognized as subspecies.They differ in plumage characteristics(such as red versus black belly patches;supercilium color and extent;and white versus black throats),in lifestyle(resident versus migratory)and in vocalizations.We investigated the morphological,bioacoustic and ecological differences across all taxa after recent studies demostrated the importance of these traits in recognizing biological species limits across pittas.Methods:Morphometric analysis was carried out by measuring tarsus,wing,tail and bill lengths of 15 specimens at the Natural History Museum,UK,and plumages were inspected across 106 unique individuals from four different repositories.Bioacoustic analysis was based on 134 range-wide sound recordings.Two types of calls,territorial calls and alarm calls,were analyzed using different sets of parameters.Principal component analysis and the Isler Criterion were applied to the measurements.Playback trials were conducted to explore the levels of response of each taxon to the call types of the other taxa.Results:The territorial call of concinna exhibits a distinct two-element motif,while elegans,maria and virginalis utter a three-element motif in which the first two elements are given in quick succession.On the other hand,vigorsii,produces both two-element and three-element motifs with longer breaks in between elements.As further corroborated by the playback trials,the three taxa elegans,virginalis and maria form a tight vocal cluster,whereas each concinna and vigorsii are distinct.The alarm call turned out to be less diagnostic even though most taxa did roughly separate into different vocal clusters.Morphometric analysis failed to produce strong differences,but plumage distinctions among multiple taxa are pronounced.Conclusions:We suggest splitting the Elegant Pitta into three biological species based on bioacoustic and—less so—plumage evidence:(1)Temminck’s Elegant Pitta P.elegans(including subspecies elegans,virginalis and maria),(2)Wallace’s Elegant Pitta P.concinna(monotypic),and(3)Banda Elegant Pitta P.vigorsii(monotypic).展开更多
GIS and remote sensing were utilized for prioritizing the W. Mujib catchment. Fifty three fourth-order sub-watersheds were prioritized based on morphometric analysis of linear and shape parameters. ASTER DEM (v.2), to...GIS and remote sensing were utilized for prioritizing the W. Mujib catchment. Fifty three fourth-order sub-watersheds were prioritized based on morphometric analysis of linear and shape parameters. ASTER DEM (v.2), topographical maps, and Arc GIS (10.1) software, have been employed to delineate the 53 sub-basins, to extract the drainage networks, and to compute the required basic, linear, and shape parameters, and to compile the necessary thematic maps such as elevation and slope categories. The land use/land cover map was generated using ERDAS Imagine (2015), LANDSAT 8 image, and supervised classification (Maximum Likelihood Method). Soil map was digitized using the Arc GIS tool. Each sub-basin is prioritized by assigning ranks based on the calculated compound parameter (Cp). The final score for each sub-basin is ascribed as per erosion threat. The 53 sub-watersheds were grouped into four categories of priority: very high (15 sub-basins, 28.3% of the total), high (17 sub-basins, 32% of the total), moderate (16 sub-basins, 30.2% of the total), and low (5 sub-basins, 9.5% of the total). Sub-basins categorized as very high and high priority (60.3% of the total) are subjected to high erosion risk, thus, creating an urgent need for applying soil and water conservation measures. The validity of the prioritized four groups was tested statistically by means of Discriminant Analysis (DA), and a significant difference was found between the four priority classes. A relatively complete separation exists between the recognized priority classes;thus, they are statistically valid, distinct, and different from each other. The present results intend to help decision makers pay sufficient attention to soil and water conservation programs, and to encourage tree plantation over the government-owned sloping land. Such procedures are essential in order to minimize soil erosion loss, and to increase soil moisture on farms, thus, reducing the impact of recurrent droughts and the possibility of flooding downstream.展开更多
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.
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.
基金supported by the National Key R&D Program of China during the 14th Five-year Plan Period(2021YFD2200302)the nonprofit industry research subject of the National Forestry and Grassland Administration in China(Grant Number 201504408)。
文摘To compare the application of traditional morphometric methods(TMMs)and geometric morphometric methods(GMMs)in the study of intraspecific leaf morphological characters of Quercus dentata,fifteen linear measurement indices and thirteen landmarks of leaves were used to study leaf morphology of three provenances(H1,H2,and H3).In TMMs,principal component analysis(PCA)showed that leaf size–related indices played an important role in population classification.Partial least square(PLS)analysis showed that the main morphological characters affecting leaf size were the average depth of the lobes and the length–width ratios.However,the important indices to distinguish the provenances were circularity,leaf width,and length–width ratio.The results of discriminant analysis(DA)showed that 74.0%of H1,68.0%of H2,and 74.0%of H3 were correctly classified.Cluster analysis showed that the Mahalanobis distances between H1 and H2,H1 and H3,and H2 and H3 were 4.3761,11.4629,and 10.2067,respectively.In GMMs,PCA based on symmetrical components showed that the difference in leaf morphology was mainly due to the changing trend of the leaf apex and base,petiole length,and degree of leaf cracking.PLS analysis showed that there was a significant covariation between the leaf symmetrical components and size:as the leaf enlarged,the widest part gradually moved up,and the shape changed from nearly oval to lanceolate.DA results showed that 86.0%and 78.0%of H1 and H2,70.0%and 80.0%of H1 and H3,and 82.0%and 76.0%of H2 and H3 were correctly classified.Canonical variate analysis results showed that the Mahalanobis distances between H1 and H2,H1 and H3,and H2 and H3 were 1.7238,1.5380,and 1.6329,respectively.Both GMMs and TMMs showed significant differences in morphology among the three Q.dentata provenances,but GMMs had higher classification accuracy and could provide more information about leaf shape,whereas TMMs could provide more information about leaf size.Based on our results,GMMs are promising in the study of leaf morphological variation within Q.dentata provenances.
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Objective: To study the relationship between the ser- um levels of hyaluronic acid (HA), procollagen type Ⅲ (PCⅢ), collagen type Ⅳ (CIV) and the histologi- cal degree of hepatic fibrosis evaluated by image analysis, and the clinical significance of serum HA, PC Ⅲ, C Ⅳ in the diagnosis of hepatic fibrosis in pa- tients with chronic viral hepatitis. Methods: The concentrations of serum HA, PC Ⅲ, C Ⅳ in 151 patients with chronic viral hepatitis were measured by radioimmunoassay. Liver biopsies were performed in all the patients. Histological sections of 4 μm thickness were stained with Masson's trichrome for fibrosis assessment. Morphometric quantitative measurements for hepatic fibrosis assessment in the 4 μm sections were performed using a fully automated image analysis system. Serum levels of HA, PC Ⅲ, and C Ⅳ were analyzed at different stages of liver pa- thology and compared with the morphometric quanti- tative measurements of hepatic fibrosis. Results: The serum levels of HA, PC Ⅲ, C Ⅳ all ele- vated gradually with the progression of the disease, and all reached the highest in patients with liver cir- rhosis. There was a significant difference in the levels of these 3 components between liver cirrhosis group and the other groups (P<0.05). They all increased steadily with the histological stages of hepatic fibrosis, and reached the highest levels in stage Ⅳ. The serum levels of HA, PC Ⅲ, C Ⅳ were all positive- ly correlated with the histological stages of liver sec- tions and the morphometric measurement (P< 0.001). The coefficients with stages were 0.694, 0.493, 0.552 (P<0.001), respectively and with sur- face density of total collagen on liver biopsy sections by image analysis were 0. 715, 0. 595, 0. 573 (P< 0.001), respectively. Conclusion: The serum levels of HA, PC Ⅲ, C Ⅳ were in consistent with the degree of hepatic fibrosis, and the determination of these marks is valuable for detecting hepatic fibrosis.
文摘Remote sensing and GIS techniques were employed for prioritization of the Zerqa River watershed. Forty-three 4th order sub-watersheds were prioritized based on morphometric and Principal Component Analysis (PCA), in order to examine the effectiveness of morphometric parameters in watershed prioritization. A comparison has been carried out between the results achieved through applying the two methods of analysis (morphometric and PCA). Afterwards, suitable measures are proposed for soil and water conservation. Topo sheets and ASTER DEM have been employed to demarcate the 43 sub-watersheds, to extract the drainage networks, and to compile the required thematic maps such as slope categories and elevation. LANDSAT 8 image (April-2015) is employed to generate land use/cover maps using ENVI (v 5.1) software. The soil map of the watershed has been digitized using Arc GIS software. Prioritization of the 43 sub-watersheds was performed using ten linear and shape parameters, and three parameters which are highly correlated with components 1 and 2. Subsequently, different sub-watersheds were prioritized by ascribing ranks based on the calculated compound parameters (Cp) using the two approaches. Comparison of the results revealed that prioritization of watersheds based on morphometric analysis is more consistent and serves for better decision making in conservation planning as compared with the PCA approach. The recommended soil conservation measures are prescribed in accordance with the specified priority, in order to avoid undesirable effects on land and environment. Sub-watersheds classified under high priority class are subjected to high erosion risk, thus, creating an urgent need for applying soil and water conservation measures. It is expected that decision makers will pay sufficient attention to the present results/information, activate programs encouraging soil conservation, integrated watershed management, and will continue working on the afforestation of the government-owned sloping lands. Such a viable approach can be applied at different parts of the rainfed highland areas to minimize soil erosion loss, and to increase infiltration and soil moisture in the soil profile, thus, reducing the impact of recurrent droughts and the possibility of flooding hazards.
基金supported by the Project of Tackling Key Problems of Science and Technology of Heilongjiang Province, China (GB06B205-3)Program of Wildlife Conservation and Breeding of State Forestry Administration of China (2008)Special Fund for Postgraduate Dissertation of Northeast Forestry University (2009)
文摘Commercial farming of anuran species that are declining in the wild raises a need to discriminate wild from farmed frogs.We hypothesized wild frogs might have extended hindlimbs due to greater frequency or intensity of jumping relative to farmed frogs,highlighting a morphometric approach to discrimination of wild from farmed frogs using hindlimb length.In the present study,Dybowski's frog(Rana dybowskii) was used to test this hypothesis.We measured body mass(Mb) and hindlimb length(Lh) of 2-year old farmed frogs and wild frogs aged 2 to 5 years.Dybowski's frog demonstrated significant dimorphism in Mb and Lh.Mb was significantly greater among farmed 2-year old frogs in both sexes(p=0.000),while only among females was Lh significantly greater for wild frogs(p=0.000).Lh/Mb was used as an index for origin discrimination to eliminate the influence of Mb due to variation of husbandry conditions among farms.Mean Lh/Mb for farmed frogs was significantly lower than for wild frogs(p=0.000) in the 2-year old age class.Discrimination correctly classified 84.4% of farmed and 96.3% of wild male frogs.Among females,92.9% of farmed frogs and 90.1% wild frogs were correctly classified.The overall correctness of classification was 92.1% and 90.8% for males and females,respectively.However,Lh/Mb revealed variation with age,resulting in reduced discriminative power for frogs ≥3 years old.We introduced a coefficient Ce to adjust the Lh/Mb of frogs ≥3 years to the level equivalent to 2-year frogs.The adjustment achieved 89.5% for overall correctness of origin for wild males and 92.4% for wild females ≥3 years old.These results show that Lh/Mb is an effective index to discriminate wild from farmed Dybowski's frog.Since the physical demands of jumping are common among anurans,this index is also potentially applicable to other anuran species.
文摘Allactaginae is a subfamily of dipodids consisting of four-and five-toed jerboas(Allactaga, Allactodipus,Orientallactaga, Pygeretmus, Scarturus) found in open habitats of Asia and North Africa. Recent molecular phylogenies have upended our understanding of this group's systematics across taxonomic scales. Here, I used cranial geometric morphometrics to examine variation across 219 specimens of 14 allactagine species(Allactaga major, A. severtzovi, Orientallactaga balikunica, O.bullata, O. sibirica, Pygeretmus platyurus, P. pumilio,P. shitkovi, Scarturus aralychensis, S. euphraticus,S. hotsoni, S. indicus, S. tetradactylus, S. williamsi)in light of their revised taxonomy. Results showed no significant sexual size or shape dimorphism. Species significantly differed in cranial size and shape both overall and as species pairs. Species identity had a strong effect on both cranial size and shape. Only a small part of cranial shape variation was allometric,with no evidence of unique species allometries, and most specimens fit closely to the common allometric regression vector. Allactaga was the largest,followed by Orientallactaga, Scarturus, and finally Pygeretmus. Principal component 1(PC1) separated O. bullata+O. balikunica+S. hotsoni(with inflated bullae along with reduced zygomatic arches and rostra) from A. major+A. severtzovi+O. sibirica(with converse patterns), while PC2 differentiated Orientallactaga(with enlarged cranial bases and rostra along with reduced zygomatic arches and foramina magna) from Scarturus+Pygeretmus(with the opposite patterns). Clustering based on the unweighted pair group method with arithmetic mean(UPGMA) contained the four genera, but S. hotsoni clustered with O. bullata+O. balikunica and O.sibirica clustered with A. major+A. severtzovi, likely due to convergence and allometry, respectively.
文摘Morphometric analysis is an indispensable tool for hydrological investigation that involves the development and management of drainage basin. This study characterizes the micro watersheds in the Palar sub-watershed using morphometric analysis and assesses its risk by land use and land cover features in a particular micro watershed. Palar sub-watershed is divided into 6 micro watersheds for prioritization based on morphometric and land use analysis. Several morphometric parameters (linear, shape and relief) are determined from the drainage map; ranks are assigned based on their capacity to induce erodability and degradation. Final ranking is based on the composite index calculated from the sum of the ranks of each morphometric parameter. Morphometric analysis reveals micro watersheds 5 and 6 as most susceptible and 2 and 3 as low susceptible. Land use is mapped using IRS ID LISS III satellite data. The risk in terms of watershed degradation involved to each micro watershed is based on the ranks of each land use feature, obtained from a similar composite index as that of morphometric analysis. Land use analysis shows that micro watersheds 2 and 4 fall under high priority category while 5 and 6 under low priority category. Integration of the morphometric and land use analysis shows that only microwatershed 1 falls under the same category in both analyses. Control measures are suggested to contain degradation depending on its specific land use pattern and morphometric features. This study ean be used to prepare a comprehensive watershed plan for the development or for planning resource conservation strategies, by integrating land use features with the drainage characteristics of the region, in particular for a hill ecosystem as the prioritization is at micro level.
文摘Extreme and prolonged rainfall in the Tunka Ridge caused several debris flows in the vicinity of the Arshan village(Siberia, Russia) on June 28, 2014. These debris flows, in spite of similar geological conditions, had different velocity, peak discharge and alluvial fan volume values. The flow velocity was from 3.5 m/s to 19.6 m/s, the peak discharge ranged from 63 m3/s to 13566 m3/s, and the alluvial fan volume varied from 4.13×103 to 8.45×105 m3. Such a great range of values is due to the morphometric parameters of the debris flow basins. The article deals with the influence of morphometric parameters of debris flow basins, such as the basin area, the average slope, Melton ratio, relief ratio on the debris flow velocity, peak discharge and volume of alluvial fans. In this debris flow event the average values of slope angle and total basin relief of the debris flow basins did not affect the values of debris flow velocity, peak discharge and alluvial fan volume. The highest correlations were observed with the debris flow basin area that was connected with the water inflow volume into the debris flow basins during the rainfall. The unequal water distribution among debris flow basins also had an impact on the debris flow velocity, peak discharge and volume of alluvial fans.
文摘Analysis of 3D measurements of 13 landmarks on 72 Yuanmou Hominoid lower molars and some comparative samples, using Euclidean Distance Matrix Analysis (EDMA), show that the 3D morphometric features of Yuanmou Homi noid lower molars largely resemble those of Lufengpithecus. Compared with extant great apes and humans, both Yuanmou Hominoid and Lufengpithecus differ markedly from humans, whereas they show much resemblance to apes. The two Chinese hominoids and extant great apes are different from humans in many of the same ways. Moreover, 3D morphometric features of Yuanmou Hominoid lower molars differ from those of each of the three extant great apes in similar ways. Of the three, the orangutan is the closest match to Yuanmou Hominoid in tooth morphology. However, the exact implications of these similarities and differences remain to be determined.
文摘The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate new varieties from Indica and Japonica cultivars. Morphometric parameters of the grains were evaluated by image analysis. Flours were prepared from the whole rice grains and physicochemical, thermal and rheological properties, X-ray diffraction pattern and evaluation of color using the CIELAB system were assessed. The hybrids lines showed long (061, 611, 721), medium (719 and 720) and short (067) grains. The rice samples presented lipids (2.6% - 3.2%), protein (11% - 15%), total dietary fiber (8.4% - 10.2%), total starch (65% - 74%) and apparent amylose (5% - 32%) contents. Gelatinization temperature (Tp) was found in the range of 66.1℃ - 79.4℃ with enthalpy (ΔH) value between 3.4 - 8.1 J/g. The retrogradation parameters (temperature and ΔH) were lower than those for gelatinization in all samples. The rice samples presented A-type X-ray diffraction pattern. Rice pastes showed a non-Newtonian behavior and the brightness (L*) characterize the color of the samples. Hybrid rice grains presented morphometric properties more similar to Japonica than Indica variety. Rice hybrid had higher protein content than Indica variety. Apparent amylose, viscosity and gelatinization temperature varied significantly among hybrids and varieties.
文摘Shrimps of genus Artemia are the inhabitants of continental and marine waters with salinity of 70 to 350 g/l and above.Artemia is able to survive in the conditions in which other animals cannot exist.This is due to adaptations:effective osmoregulation system,the ability to synthesize of respiratory pigment(hemoglobin)and diapauses cysts(Litvinenko at.al.,2009).Cysts of this
文摘The Douala-Buea Region(DBR;4°-5°N,9°-10°30’E),a portion of the southern Cameroon passive margin,developed on the Proterozoic granito-gneissic basement and the Cretaceous to Recent volcanosedimentary cover,was explored in order to evaluate the lithology and tectonics controls on its landscape usingthequalitativeandquantitative geomorphological analyses based on 30 m resolution Digital Elevation Models(DEM)and field evidences.This area displays an uneven and complex landscape differentiated into four morphological units:Douala,Nkondjock,Kumba and Buea Units.The Douala Unit corresponds to the Coastal Plain and is extended on the Douala-Kribi/Camposedimentarybasin.The Nkondjock Unit represents a middle plateau developed on a Proterozoic granito-gneissic basement.The Kumba Unit matches with the southernmost volcanic Western Cameroon High Plateau.The Buea Unit corresponds to the Mount Cameroon stratovolcano.The relief analysis through mountain-front sinuosity(Smf,1.19–1.43)and relative relief ratio(Rr,0.10–2.31)vary from one unit to another.The drainage network analysis including drainage patterns,stepped longitudinalriverprofiles,theassociated morphometric indexes,notably the concavity index(IC,0.56–0.88),deviation(D,267–2912 m),basin asymmetry factor(A_(F),6.37–42.12),hypsometric integral(HI,0.10–0.29),valley floor width to valley height ratio(V_(f),0.36–2.75),elongation ratio(R_(e),0.30–0.50),watershed slope(S,6.88–88.88)and stream length gradient index(SL,0–3332)vary from one basin to another too.These results also show the heterogeneous and uneven DBR landscape controlled by its lithology and active tectonics.The drainage system reveals concave to concavo-convex longitudinal river profile shapes with knick points,asymmetric basins,and fault reactivations,and highlights the tectonics activity that used to occur through the time and their control on the morphology.Together,they document the lithostructural controls on the DBR landscape evolution,extendable in the whole SW Cameroon margin.
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.
文摘Background:The Elegant Pitta(Pitta elegans)complex displays a remarkable diversity of morphological and bioacoustic traits across five taxa currently recognized as subspecies.They differ in plumage characteristics(such as red versus black belly patches;supercilium color and extent;and white versus black throats),in lifestyle(resident versus migratory)and in vocalizations.We investigated the morphological,bioacoustic and ecological differences across all taxa after recent studies demostrated the importance of these traits in recognizing biological species limits across pittas.Methods:Morphometric analysis was carried out by measuring tarsus,wing,tail and bill lengths of 15 specimens at the Natural History Museum,UK,and plumages were inspected across 106 unique individuals from four different repositories.Bioacoustic analysis was based on 134 range-wide sound recordings.Two types of calls,territorial calls and alarm calls,were analyzed using different sets of parameters.Principal component analysis and the Isler Criterion were applied to the measurements.Playback trials were conducted to explore the levels of response of each taxon to the call types of the other taxa.Results:The territorial call of concinna exhibits a distinct two-element motif,while elegans,maria and virginalis utter a three-element motif in which the first two elements are given in quick succession.On the other hand,vigorsii,produces both two-element and three-element motifs with longer breaks in between elements.As further corroborated by the playback trials,the three taxa elegans,virginalis and maria form a tight vocal cluster,whereas each concinna and vigorsii are distinct.The alarm call turned out to be less diagnostic even though most taxa did roughly separate into different vocal clusters.Morphometric analysis failed to produce strong differences,but plumage distinctions among multiple taxa are pronounced.Conclusions:We suggest splitting the Elegant Pitta into three biological species based on bioacoustic and—less so—plumage evidence:(1)Temminck’s Elegant Pitta P.elegans(including subspecies elegans,virginalis and maria),(2)Wallace’s Elegant Pitta P.concinna(monotypic),and(3)Banda Elegant Pitta P.vigorsii(monotypic).
文摘GIS and remote sensing were utilized for prioritizing the W. Mujib catchment. Fifty three fourth-order sub-watersheds were prioritized based on morphometric analysis of linear and shape parameters. ASTER DEM (v.2), topographical maps, and Arc GIS (10.1) software, have been employed to delineate the 53 sub-basins, to extract the drainage networks, and to compute the required basic, linear, and shape parameters, and to compile the necessary thematic maps such as elevation and slope categories. The land use/land cover map was generated using ERDAS Imagine (2015), LANDSAT 8 image, and supervised classification (Maximum Likelihood Method). Soil map was digitized using the Arc GIS tool. Each sub-basin is prioritized by assigning ranks based on the calculated compound parameter (Cp). The final score for each sub-basin is ascribed as per erosion threat. The 53 sub-watersheds were grouped into four categories of priority: very high (15 sub-basins, 28.3% of the total), high (17 sub-basins, 32% of the total), moderate (16 sub-basins, 30.2% of the total), and low (5 sub-basins, 9.5% of the total). Sub-basins categorized as very high and high priority (60.3% of the total) are subjected to high erosion risk, thus, creating an urgent need for applying soil and water conservation measures. The validity of the prioritized four groups was tested statistically by means of Discriminant Analysis (DA), and a significant difference was found between the four priority classes. A relatively complete separation exists between the recognized priority classes;thus, they are statistically valid, distinct, and different from each other. The present results intend to help decision makers pay sufficient attention to soil and water conservation programs, and to encourage tree plantation over the government-owned sloping land. Such procedures are essential in order to minimize soil erosion loss, and to increase soil moisture on farms, thus, reducing the impact of recurrent droughts and the possibility of flooding downstream.