scholarly journals Meristic character variability among populations of Silurus triostegus Heckel, 1843 from the Euphrates, Tigris, and Shatt al-Arab Rivers, Iraq

2017 ◽  
Vol 25 (1) ◽  
pp. 21-31
Author(s):  
Laith A. Jawad ◽  
Alessandro Ligas ◽  
Muhammad I.G. Al-Janabi

Abstract Variation in the numbers of pectoral fin spines and rays, pelvic fin rays, gill rakers on the first gill arch, anal fin rays, and the number of vertebrae of Silurus triostegus Heckel were examined in specimens from 16 localities that span its entire distribution range in the Tigris, Euphrates, and Shatt al-Arab rivers in Iraq. The mean number of the six meristic traits increases toward high latitudes with maximum and minimum values in the north and south of Iraq. Based on cluster analysis and PCA, the Mesopotamian river samples were clearly separated into three distinct groups. The upper Tigris populations were isolated from those of the middle and southern populations of this river and from those of the Euphrates River. Possible reasons for such differentiation among populations are discussed, and the integration of research on this species among the countries neighboring Iraq is required.

2011 ◽  
Vol 9 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Frank Raynner V Ribeiro ◽  
Carlos Alberto S. de Lucena ◽  
Osvaldo T Oyakawa

Pimelodus multicratifer, a new species, is described from the rio Ribeira de Iguape basin. The new species differs from the other Pimelodus species by the following features: 26 to 30 gill rakers on the first branchial arch; a combination of three to six rows of dark spots regularly or irregularly scattered on the flanks and several small dark spots irregularly scattered on the dorsal surface of head, supraoccipital process, and sometimes on the dorsal and caudal fins; striated lips; maxillary barbels reaching between posterior tip of the pelvic-fin rays and posterior tip of the middle caudal-fin rays.


2011 ◽  
Vol 8 (1) ◽  
pp. 552-560
Author(s):  
Baghdad Science Journal

The heavy metals Cd, Cu, Fe, pb, and Zn were determined in dissolved and particulate phases of the water,in addition to exchangeable and residual phases of the sediment and in the selected organs of the fish Cyprinus carpio collected from the Euphrates River near Al-Nassiriya city center south of Iraq during the summer period / 2009 .Also sediment texture and total organic carbon(TOC) were measured. Analysis emploing a flam Atomic Absorption Spectrophotometers . The mean regional concentrations of the heavy metals in dissolved (µg/l) and particulate phases (µg/gm) dry weight were Cd (0.15,16.13) ,Cu (0.59,24.48) ,Fe (726,909.4) ,Pb (0.20, 49.95) and Zn (2.5,35.62) respectively,and those for exchangeable and residual phases of the Sediment were Cd (0.2,0.1) ,Cu (13.75,16.65) ,Fe (683 , 1351 ) ,Pb (10.1,1.07) and Zn (7.3,16.75)µg/gm dry weight respectively. The heavy metals concentrations in C. carpio organs followed the trend gill > liver > kidney> muscles . The mean concentration in the muscles were Cd (ND) , Cu (0.07) , Fe (4.7) , pb (0.06) and Zn (6.4) (µg/gm) dry weight . The statistical analysis proved a significant correlation between metal concentration in the sediment and total organic carbon, also a positive correlation was proved between its concentrations in the liver organ and the water (particulate phase) . In conclusion the trace metals concentration in particulate phase were higher than its concentration in the dissolved phase . The fish organs showed variations in the metals concentration and the muscle organs showed less concentration than the other organs .


2016 ◽  
Vol 3 (2) ◽  
pp. 46
Author(s):  
Ghorbanali Ebrahimi ◽  
Hadi Razeghimaleh

<p>The main objective of this study was to find out whether social capital and its dimensions affect the cultural capital of citizens in Tehran, and whether there is any difference in the social capital and cultural capital in the north and south urban neighborhoods. To answer these questions, a fuzzy questionnaire for collecting the data was designed. The research method in this study was based on Artificial Neural Network -Fuzzy Inference System (ANNFIS). Statistical population included individuals aged 18 and above residing in Tehran, and sample size consisted of 2538 people.</p><p>The findings of this study indicated that there is a significant difference in the cultural capital between north and south neighborhoods in Tehran. The mean of cultural capital in the south neighborhoods (2.49 out of 10) was higher than that of north neighborhoods (6.77 out of 10). Furthermore, the degree of neighborhood social capital was different between the north and south neighborhoods of Tehran, and this difference was statistically significant, so that the mean of social capital in the south neighborhoods (6.75 out of 10) was greater than that of north neighborhoods (2.88 out of 10).</p>Multivariate linear regression analysis to explain cultural capital has revealed that social trust (- 0.502) and relation networks (- 0.087) exerted the highest and lowest impact on the dependent variable, respectively. It should be noted that, of the three variables entered into the regression equation, all variables have remained in the equation. It should be noted that the effects of all variables on the dependent variable of cultural capital was negative.


2020 ◽  
Vol 117 (26) ◽  
pp. 14764-14768 ◽  
Author(s):  
Wanying Kang ◽  
Glenn Flierl

The ice shell on Enceladus, an icy moon of Saturn, exhibits strong asymmetry between the northern and southern hemispheres, with all known geysers concentrated over the south pole, even though the expected pattern of tidal forced deformation should be symmetric between the north and south poles. Using an idealized ice-evolution model, we demonstrate that this asymmetry may form spontaneously, without any noticeable a priori asymmetry (such as a giant impact or a monopole structure of geological activity), in contrast to previous studies. Infinitesimal asymmetry in the ice shell thickness due to random perturbations are found to be able to grow indefinitely, ending up significantly thinning the ice shell at one of the poles, thereby allowing fracture formation there. Necessary conditions to trigger this hemispheric symmetry-breaking mechanism are found analytically. A rule of thumb we find is that, for Galilean and Saturnian icy moons, the ice shell can undergo hemispheric symmetry breaking only if the mean shell thickness is around 10 to 30 km.


Zootaxa ◽  
2007 ◽  
Vol 1646 (1) ◽  
pp. 31-39 ◽  
Author(s):  
JUAN MARCOS MIRANDE ◽  
GAST[N AGUILERA ◽  
MARQA DE LAS MERCEDES AZPELICUETA

Astyanax puka, new species from the endorheic RRo SalR basin, is diagnosed by the following combination of characters: shallow body (33.5–39.8 % SL), 36–38 perforated scales in lateral line, 6/5 transverse scales, 9–10 gradually decreasing dentary teeth, distally expanded premaxillary teeth, one distally expanded maxillary tooth with 7–9 cusps, short upperjaw length (34.5–37.8 % HL), short maxilla (20.7–23.3 % HL) expanded abruptly under maxillary tooth position, short postorbital distance (36.6–46.9 % HL), short distance between pelvic and anal-fin origins (17.1–20.6 % SL), 22–27 branched anal-fin rays, long caudal peduncle (13.3–16.5 % SL), bony hooks restricted to pelvic-fin rays 2 to 6 and anterior 6–13 branched anal-fin rays on mature males, and the presence of broad denticles on anterior, lateral, and posterior edges of first ceratobranchial gill rakers.


Zootaxa ◽  
2017 ◽  
Vol 4242 (3) ◽  
pp. 565 ◽  
Author(s):  
DAVUT TURAN ◽  
CÜNEYT KAYA ◽  
ESRA BAYÇELEBİ ◽  
YUSUF BEKTAŞ ◽  
F. GÜLER EKMEKÇİ

Three new Alburnoides species are described from the southern Black Sea basin. Alburnoides kurui, new species, from the Yeşilırmak drainage, is distinguished from other species of Alburnoides in the southern Black Sea basin, the Marmara basin and the Anatolian Aegean basin by having a scaleless keel between the posterior pelvic fin base and the anus or with rarely 1 scale covering the anterior part of the keel; 50–59 total lateral-line scales; 13½–15½ branched anal-fin rays and 7–9 gill rakers. Alburnoides freyhofi, new species, from the Kızılırmak drainage, is distinguished by having a scaleless keel between the posterior pelvic fin base and the anus, 44–53 total lateral-line scales; 14½–16½ branched anal-fin rays and 5–7 gill rakers. Alburnoides kosswigi, new species, from the Sakarya drainage, is distinguished by having a scaleless keel between the posterior pelvic fin base and the anus or rarely with 1–3 scales covering the anterior part of the keel; 43–57 total lateral-line scales; 11½–13 (14)½ branched anal–fin rays and 5–7 gill rakers. 


2021 ◽  
Vol 13 (01) ◽  
pp. 12-23
Author(s):  
Ali Shkhair Younus ◽  
◽  
Sahib Neamh Abdul Wahid ◽  

Turbidity was calculated by solar irradiance (Linke's Turbidity) for sixteen Iraqi sites. These sites were distributed among middle, north and south of Iraq. We have updated these results of turbidity by depending on direct solar radiation, diffuse solar radiation, total solar radiation, and solar constant as inputs for mathematical models in computer programs. The latter calculations taking into account the hours of actual sun shine, hours of theoretical sun shine of the sun, the angle of the sun's rays, and the angle of the sun during the months of the year. The results showed that turbidity in the Iraqi sites which considered in this research depends mainly on the months of the year regardless of the fact that this site is located in the north, middle or south of Iraq. The amount of turbidity is at its greatest value during the winter season, specifically the month of December, where the average turbidity varied for those sites. In latter month the turbidity was ranged from (4.85 to 5.73), while in January it ranged from (4.75 to 5.72), then it began to decrease until the value of turbidity in most sites reached its lowest level in September, where the average turbidity of the studied sites varied (except for the site of Najaf) in this month (2.82 - 3.10) While the Najaf site was unique in registering the lowest average amount of turbidity in June by (3.25). The results showed that the turbidity in all sites included in this research ranges between (2.82 - 5.73) during the year.


Author(s):  
Andri Wibowo

Recently on the December 4, 2021 at 03:00 PM, 3676 m high Mount Semeru located in the East parts of Java Island has erupted. To our best knowledge, an immediate and rapid systematic analysis of the volcanic ash plume courses, PM2.5 emissions, and environmental impacts based on Mount Semeru eruption has not been implemented so far. Then, this research aims to provide and fill the research gap on the rapid assessment of recent Mount Semeru eruption. From the result, it is clearly visible that for 12 hours the volcanic ash plume course was eastward. The volcanic ash plume can travel a distance of 0&ndash;10 km to the North and South directions, and more than 10 km to the East direction. The size of the volcanic ash plume was large at 02:00 AM on December 5, 2021. The smallest size of a volcanic ash plume was recorded at 09:00 PM on December 4, 2021. Most parts of the ash plume (55.98%) or equals 39.01 km2 contain fallen volcanic material amounts ranged from 1 kg/m2 to 10 kg/m2. The fallen volcanic material amount peaked between 08:00 PM and 11:00 PM. Based on the estimation, the PM2.5 content in the atmosphere increased after the eruption. The mean of PM2.5 before the eruption was 48.5 &plusmn; 19.3(95%CI: 29.2 to 67.8 ug/m3). While after eruption the mean of PM2.5 was 79.4 &plusmn; 32.2(95%CI: 47.2 to112 ug/m3). It indicated that the Mount Semeru eruption has increased the PM2.5 equals 63.65%.


2021 ◽  
Vol 39 (2) ◽  
pp. 357-368
Author(s):  
Andrey V. Koval ◽  
Wen Chen ◽  
Ksenia A. Didenko ◽  
Tatiana S. Ermakova ◽  
Nikolai M. Gavrilov ◽  
...  

Abstract. Ensemble simulation of the atmospheric general circulation at altitudes up to the lower thermosphere is performed using the 3-D nonlinear mechanistic numerical model MUAM. The residual mean meridional circulation (RMC), which is the superposition of the mean Eulerian and wave-induced eddy components, is calculated for the boreal winter. Changes in the vertical and meridional RMC velocity components are analysed at different stages of a simulated composite sudden stratospheric warming (SSW) event averaged over 19 model runs. The simulation results show a general decrease in RMC velocity components up to 30 % during and after SSW in the mesosphere and lower thermosphere of the Northern Hemisphere. There are also increases in the downward and northward velocities at altitudes of 20–50 km at the northern polar latitudes during SSW. Associated vertical transport and adiabatic heating can contribute to warming the stratosphere and downward shifting of the stratopause during the composite SSW. The residual mean and eddy mass fluxes are calculated for different SSW stages. It is shown that before the SSW, planetary wave activity creates wave-induced eddy circulation cells in the northern upper stratosphere, which are directed upwards at middle latitudes, northward at high latitudes and downwards near the North Pole. These cells increase heat transport and adiabatic heating in the polar region. During SSW, the region of upward eddy vertical velocity is shifted to high latitudes, but the velocity is still downward near the North Pole. After SSW, upward eddy-induced fluxes span the entire polar region, producing upward transport and adiabatic cooling of the stratosphere and providing the return of the stratopause to higher altitudes. The obtained statistically significant results on the evolution of RMC and eddy circulation at different SSW stages at altitudes up to the lower thermosphere can be useful for a better understanding the mechanisms of planetary wave impacts on the mean flow and for the diagnostics of the transport of conservative tracers in the atmosphere.


1991 ◽  
Vol 21 (10) ◽  
pp. 1439-1446 ◽  
Author(s):  
J. M. Schmid ◽  
S. A. Mata ◽  
R. A. Schmidt

Bark temperatures on the north and south sides of five ponderosa pines (Pinusponderosa Laws.) in each of four growing stock levels in two areas in the Black Hills of South Dakota were monitored periodically from May through August 1989. Temperatures were significantly different among growing stock levels and between sides of the tree. The magnitude of differences between the mean bark temperatures in partially cut stands and uncut controls was inversely related to stocking level. Maximum differences in mean bark temperatures among the growing stock levels occurred between 10:00 and 14:00, when differences between the lower growing stock levels and the controls reached 9 to 10°F (Fahrenheit temp. = 1.8(Celsius temp.) + 32). Diurnal differences were greatly influenced by the amount of cloud cover. Nocturnal temperatures generally differed by 1 to 2°F. North-side temperatures were cooler and less variable than south-side temperatures. Temperature relationships and mountain pine beetle (Dendroctonusponderosae Hopk.) behavior are discussed.


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