scholarly journals Morphological Changes of the Lower Tedori River, Japan, over 50 Years

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1852 ◽  
Author(s):  
Minh Hai ◽  
Umeda ◽  
Yuhi
Keyword(s):  
Morphological Changes ◽  
Morphological Characteristics ◽  
River Mouth ◽  
River Basin Management ◽  
Second Phase ◽  
Related Data ◽  
Sediment Extraction ◽  
Term Variation ◽  
Critical Slope

Long-term variation in the morphological characteristics of rivers is complicated as a result of temporally and spatially variable natural processes and anthropogenic disturbances. Better understanding of their relationship is therefore important for river basin management. The present study conducted a detailed analysis of a long-term dataset consisting of a 58-year topographic survey and related data on human impact to clarify the long-term variation in the morphological characteristics of the lower Tedori River in Japan. An empirical model was established through the assessment of spatiotemporal variations in nonlinear rates of adjustment. The results indicated that sediment extraction and dam construction profoundly affected the morphological characteristics of the lower Tedori River and that the vertical adjustment of the river channel experienced five phases. Degradation occurred from 7 to 16 km upstream from the river mouth over all phases. Two aggradation phases following two degradation phases were observed from the river mouth to 2 km upstream. Aggradation and degradation phases appeared alternately from 2 to 7 km. The representative nonlinear rates of vertical adjustment in the second phase were the highest compared with those in the other phases in the entire reach. The correlation analysis revealed that the incision phase was mostly coupled with channel narrowing, while widening followed the deposition phase. It was deduced from aerial photo analysis and a comparison between slope and empirical critical slope that the pattern in the lower Tedori River was braided during the period 1950–2000.

scholarly journals Sex ratio and morphological characteristics of rufous gnateaters, Conopophaga lineata (Aves, Passeriformes) in Atlantic forest fragments

2009 ◽  
Vol 99 (1) ◽  
pp. 115-119 ◽  
Author(s):  
Gisele P. M. Dantas ◽  
Fabrício R. Santos ◽  
Miguel Ângelo Marini
Keyword(s):  
Sex Ratio ◽  
Morphological Changes ◽  
Anthropogenic Activities ◽  
Natural Populations ◽  
Morphological Characteristics ◽  
Atlantic Rain Forest ◽  
Forest Fragments ◽  
Natural Habitats ◽  
Term Survival

Unequal sex ratios lead to the loss of genetic variability, decreasing the viability of populations in the long term. Anthropogenic activities often disturb the natural habitats and can cause alterations in sex ratio and morphological characteristics of several species. Forest fragmentation is a major conservation concern, so that understanding its effects in natural populations is essential. In this study, we evaluated the sex ratio and the morphological characteristics of Rufous Gnateaters (Conopophaga lineata (Wied, 1831)) in small and large forest fragments in Minas Gerais, Brazil. Birds (n = 89) were sexed by plumage characteristics and molecular markers. The molecular analysis showed that plumage is not a totally reliable method for sexing Rufous Gnateaters. We observed that sex ratio did not differ between large and small forest fragments, but birds in small fragments had larger wings and tarsus. Wing and tarsus changes may affect the movement ability of individuals within and among forest fragments. In conclusion, Rufous Gnateaters have been able to survive in both small and large Atlantic rain forest fragments without altering their sex ratio, but morphological changes can be prejudicial to their long term survival.

scholarly journals BEACH MORPHOLOGIES AT NOTSUKEZAKI SAND SPIT, JAPAN

2011 ◽  
Vol 1 (32) ◽  
pp. 48 ◽  
Author(s):  
Kentaro Hayashi ◽  
Koji Hayashimoto ◽  
Kazuki Yagisawa ◽  
Nobuhisa Kobayashi
Keyword(s):  
Numerical Model ◽  
Morphological Changes ◽  
Morphological Characteristics ◽  
Field Observations ◽  
Aerial Photos ◽  
Wave Hindcast ◽  
Beach Processes ◽  
Sand Spit ◽  
Term Field

Notsukezaki Sand Spit is the longest sand spit in Japan and the wave and morphological characteristics vary along the spit. The main purpose of this study is to investigate the morphological changes of the sand spit for long-term and mid-term field observations and aerial photos. The natural and morphological characteristics are investigated based on the field observations and aerial photos for a long-term period (decades). The regional sediment budget is estimated using the shoreline changes and the result of wave hindcast simulation for five years. Finally, the cross-shore beach processes are examined using the numerical model, CSHORE.

Sediment transport modelling of the Drava River confluence

2020 ◽  
Author(s):  
Antonija Cikojević ◽  
Gordon Gilja ◽  
Sándor Baranya ◽  
Neven Kuspilić ◽  
Flóra Pomázi
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Morphological Changes ◽  
River Mouth ◽  
Transport Modelling ◽  
River Confluence ◽  
Drava River ◽  
Sediment Transport Modelling ◽  
Transport Method

<p>Drava River confluence is characterized by specific morphodynamic processes under which significant sediment deposition is occurring at the Drava River mouth, impeding fairway conditions. Morphodynamic analysis requires long-term hydraulic and sediment transport regime data as input for estimation of equilibrium conditions, taking into account baseline conditions of both rivers. This paper presents results of detail investigations of morphodynamic changes at the Drava River confluence during the 2-year period. Quantification of morphodynamic processes is conducted indirectly through interpretation of ADCP transects surveyed over wider confluence zone, estimation of sediment transport intensity and bathymetric surveys. Purpose of the conducted analysis was to estimate morphodynamic development of the riverbed based on the 1D numerical model results. Numerical model is calibrated using flow velocity field and sediment transport pattern for range of hydrological events. Validation of sediment transport method is done through comparison of morphological changes on characteristic profiles between two consecutive surveys.</p>

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

Comparative assessment of morphological mechanisms of maintaining structural liver homeostasis in the dynamics of exposure to coal-rock dust and sodium fluoride on the body

2020 ◽  
pp. 189-194
Author(s):  
M. S. Bugaeva ◽  
O. I. Bondarev ◽  
N. N. Mikhailova ◽  
L. G. Gorokhova
Keyword(s):  
Sodium Fluoride ◽  
Morphological Changes ◽  
The Body ◽  
System Level ◽  
Production Factor ◽  
Coal Rock ◽  
The Impact ◽  
Structural Homeostasis ◽  
Rock Dust

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.

Characteristics of the course of nephritis associated with Iga-vasculitis Henoch-Schoenlein in children

2020 ◽  
Vol 24 (3) ◽  
pp. 64-71
Author(s):  
A. V. Sukalo ◽  
I. A. Kazyra
Keyword(s):  
Clinical Laboratory ◽  
Morphological Changes ◽  
Pediatric Nephrology ◽  
Morphological Characteristics ◽  
Lymphocyte Activation ◽  
Renal Tissue ◽  
Kidney Damage ◽  
Iga Vasculitis ◽  
Factors Affecting ◽  
Treatment Regimens

INTRODUCTION. Among systemic vasopathies in children, IgA vasculitis Henoch Schoenlein (HS) is the most common, according to various authors, kidney damage is noted in 25-80 % and usually determines the prognosis of the disease.THE AIM of the study was to analyze clinical, laboratory, immunological, morphological characteristics, features of the course and treatment of nephritis associated with IgA vasculitis HS in children, as well as factors affecting the prognosis.PATIENTS AND METHODS. The study included 31 patients with morphologically verified nephritis due to IgA vasculitis HS (18 – boys, 13 – girls) aged 3 to 17 years, who were monitored at the Nephrology Department of the "2nd Children's City Clinical Hospital" of the National Center for Pediatric Nephrology and Renal Replacement therapy in Minsk from 2010 to 2019 yrs.The following parameters were analyzed: the clinical variant of kidney damage, laboratory tests (including the study of BAFF, RANTES lymphocyte activation molecules, pro-inflammatory IL1β, caspase1, TNFα, growth factors VEGF, TGF), 24 hours monitoring and office blood pressure measurements, ECHO cardiography with indicescalculation, ultrasound of the carotid arteries with the thickness of intima-media complex, morphological changes in the renal tissue, as well as treatment regimens.RESULTS. The contribution of deGal-IgA1, markers of T and B lymphocytes activation, pro-inflammatory and profibrotic molecules in the development of the disease is shown. Arterial hypertension was registered in 42 % of children, signs of heart remodeling according to the calculated indices in 19,3 %. Decrease level of adiponectin, vitamin D, leptin, increase concentration of obestatin, Pro-BNP, hs-CRP, and TSAT indicator classify patients with nephritis due to IgA vasculitis HS at moderate risk for the developmentof cardio-vascular disorders, which suggests the need for timely correction.CONCLUSION. In most cases, nephritis with IgA vasculitis HS has a benign course with rare relapses and progression to the end stage of chronic kidney disease (6,5 %).

scholarly journals Myxomatous Mitral Valve Disease with Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical and Functional Significance of the Coincidence

2021 ◽  
Vol 8 (2) ◽  
pp. 9
Author(s):  
Nina C. Wunderlich ◽  
Siew Yen Ho ◽  
Nir Flint ◽  
Robert J. Siegel
Keyword(s):  
Mitral Valve ◽  
Mitral Valve Disease ◽  
Morphological Changes ◽  
Morphological Characteristics ◽  
Mitral Annulus ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Valve Disease ◽  
Left Ventricular Myocardium ◽  
Basal Portion

The morphological changes that occur in myxomatous mitral valve disease (MMVD) involve various components, ultimately leading to the impairment of mitral valve (MV) function. In this context, intrinsic mitral annular abnormalities are increasingly recognized, such as a mitral annular disjunction (MAD), a specific anatomical abnormality whereby there is a distinct separation between the mitral annulus and the left atrial wall and the basal portion of the posterolateral left ventricular myocardium. In recent years, several studies have suggested that MAD contributes to myxomatous degeneration of the mitral leaflets, and there is growing evidence that MAD is associated with ventricular arrhythmias and sudden cardiac death. In this review, the morphological characteristics of MAD and imaging tools for diagnosis will be described, and the clinical and functional aspects of the coincidence of MAD and myxomatous MVP will be discussed.

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