Segmented regression consists of several sections separated by different points of membership, showing the heterogeneity arising from the process of separating the segments within the research sample. This research is concerned with estimating the location of the change point between segments and estimating model parameters, and proposing a robust estimation method and compare it with some other methods that used in the segmented regression. One of the traditional methods (Muggeo method) has been used to find the maximum likelihood estimator in an iterative approach for the model and the change point as well. Moreover, a robust estimation method (IRW method) has used which depends on the use of the robust M-estimator technique in

The objective of this study is to evaluate the bacterial count and heavy metal concentration of river water on fish micronuclei. Fish and water samples are carried out in 1 May to 1 June 2013 from Tigris River. A total of fifty three fish sample are studied. The bacteriological quality of water showed that the total viable count is ranged from 150×103 to 352×103 cfu/ml and fecal coliform counts was 1250 cell/100ml during the study period. All the metals (Cu, Hg, Pb, and Zn) are within the normal limit, but Cd was slightly elevated in river water samples. The appearance of micronuclei in red blood cells of all fish species is detect , by recording a larger number of it, in ( Abu Alsomere , Hishne , Bannini Kaber al fam & Karkoor

Abstract

The analysis of Least Squares: LS is often unsuccessful in the case of outliers ​​in the studied phenomena. OLS will lose their properties and then lose the property of Beast Linear Unbiased Estimator (BLUE), because of the Outliers have a bad effect on the phenomenon. To address this problem, new statistical methods have been developed so that they are not easily affected by outliers. These methods are characterized by robustness or (resistance). The Least Trimmed Squares: LTS method was therefore a good alternative to achieving more feasible results and optimization. However, it is possible to assume weights that take into consideration the location of the outliers ​​in the data and det

Sodium adsorption ratio (SAR) is considered as a measure of the water suitability for irrigation usage. This study examines the effect of the physicochemical parameters on water quality and SAR, which included Calcium(Ca+2), Magnesium(Mg+2), Sodium (Na+), Potassium (K), Chloride (Cl-), Sulfate(SO4-2), Carbonate (CO3-2), Bicarbonate (HCO3-), Nitrate (NO3-), Total Hardness (TH), Total Dissolved Salts (TDS), Electrical Conductivity (EC), degree of reaction (DR), Boron (B) and the monthly and annually flow discharge (Q). The water samples were collected from three stations across the Tigris River in Iraq, which flows through Samarra city (upstream), Baghdad city (central) and the end of Kut city (downstream) for the periods of 2016-201

This study was carried out to determine the effects of some environmental variables on biodiversity index value of benthic invertebrates' community in samples that collected monthly from two adjacent sites nearby the confluence of Tigris and Diyala rivers within Baghdad city that’s from November 2007 - October 2008. Results showed differences in chemical and physical characteristics for each river. Where the annual averages of these characteristics in Rivers Tigris and Diyala respectively for: water temperature (20, 19) Cº, pH (8, 8), Dissolved oxygen DO(8,4 ) mg/l , EC(1152,2979)µc/cm , Turbidity (28,74) NTU, Total Hardness of CaCO3 (485,823)mg/l, and finally NO3 (4,6)mg/l. Concerning the biological groups, included types of Insect

Differences in transversal sections and activities of geomorphological operations led to forming geomorphological shapes as river turns and river isles in watercourse in the area of study. The study showed three river turns that are Sindia turn with length 4723m, turn wave 3599 average width 267.6, Zanbour turn length 11374m, turn wave 7110 average width 307.5m,and Dojama turn with length 5876m, turn wave 4982m average width 313.4m. This difference is caused by the activity of erosion and sedimentation that led to the appearance of the length rivers turn.
The study showed that the turn of Dojama is the only corresponding turn, whereas the phenomena of corresponding never appeared in other turns in the area of study. The study also sho

The foreguts of a total of 515 fish of Chondrostoma regium (Heckel, 1843) (locally: Bala’aot Malloky) were studied. These fish were collected from Tigris River at Salah Al-Deen Province (between Al-Hagag & Yathrib) for 20 months between March and October of the next year. Detritus, plant in origin materials (19.6%, 23.0% & 24.9%); green and blue green algae, mostly Cladophora, Cosmarium and Merismpedia sp. (17.1%, 12.9% & 12.2%) and diatoms, mostly Diatoma, Chanathes, Amphora and Cyulbella sp. (16.9%, 8.8% & 8.2%) were the main food categories taken by these fishes according to occurrence (O%), volumetric methods (V%) and ranking index (R%). Debris (not part of the diet) took 45.3% of the studied fish foreguts by volume. Detritus was also