The extended gamma distribution with regression model and applications

This paper introduces a new extension of the gamma distribution, named as a new extended gamma distribution, via mixture representation of xgamma and gamma distributions. The statistical properties of the proposed distribution are derived such as moment generating and characteristic functions, variance, skewness, and kurtosis measures, Lorenz curve, and mean residual life function. The maximum likelihood, parametric bootstrap, method of moments, least squares, and weighted least squares estimation methods are considered to obtain the unknown model parameters. The finite sample performance of estimation methods is discussed via a simulation study. Using the proposed distribution, we propose a new regression model for the right-skewed response variable as an alternative to the gamma regression model. Two real data sets are analyzed to convince the readers for the usefulness of the proposed model

One-stage lingual augmented urethroplasty in repair of distal penile hypospadias

AbstractObjectivesTo evaluate the outcome of augmentation of shallow urethral plate by lingual graft in repair of distal penile hypospadias.Patients and methodsBetween June 2008 and May 2011, the procedure was performed on 23 patients with mean age 2.3 years (range 1–3). All patients had distal penile hypospadias; 11 sub coronal and 12 coronal. The urethral plate was less than 8mm in all patients and 3 of them had history of previous hypospadias surgery. All procedures were carried out under general anesthesia using 4× magnifying loupe. After penile degloving and dorsal incision of the urethral plate, the lingual graft was harvested and sutured to the edges of the incised urethral plate from the hypospadias opening to the tip of the penis. The neourethra was closed and an intervening flap was fixed over the neourethra as a barrier against fistula formation.ResultsSuccess rate was 87% as 20/23 patients were cured without any permanent complication throughout the follow up period. None of patients suffered meatal stenosis or required regular urethral dilatation. Three patients developed urethrocutaneous fistula, of which two closed spontaneously and one required surgical repair 6 months later. Two patients had failed procedures and delayed re-intervention was performed due to complete loss of the graft in one of them and repair disruption following infection in the other. Two patients had post-operative pain in the graft harvesting site which disappeared within days.ConclusionThe one-stage lingual augmented urethral plate urethroplasty offers promising outcomes for repair of distal penile hypospadias with narrow urethral plate

Cancer Risk Assessment and Geochemical Features of Granitoids at Nikeiba, Southeastern Desert, Egypt

Different rock types (syenogranite, alkali feldspar granite and quartz syenite intruded by microgranite dikes and quartz veins) were investigated in the Nikeiba region in Egypt. The main components of the studied intrusive rocks, comprised of granites and quartz syenite, are plagioclase, amphibole, biotite, quartz and K-feldspar in different proportions. Ground gamma ray measurements show that syenogranite, quartz syenite and microgranite dikes have the highest radioactivity (K, eU, eTh and their ratios) in comparison with alkali feldspar granite. Geochemically, syenogranite, alkali feldspar granite and quartz syenite are enriched with large-ion lithophile elements (LILE; Ba, Rb, Sr) and high field-strength elements (HFSE; Y, Zr and Nb), but have decreased Ce, reflecting their alkaline affinity. These rocks reveal calc–alkaline affinity, metaluminous characteristics, A-type granites and post-collision geochemical signatures, which indicates emplacement in within-plate environments under an extensional regime. U and Th are increased in syenogranite and quartz syenite, whereas alkali feldspar granite shows a marked decrease in U and Th. The highest average values of AU (131 ± 49 Bq·kg−1), ATh (164 ± 35) and AK (1402 ± 239) in the syenogranite samples are higher than the recommended worldwide average. The radioactivity levels found in the samples are the result of the alteration of radioactive carrying minerals found inside granite faults. The public’s radioactive risk from the radionuclides found in the investigated granitoid samples is estimated by calculating radiological risks. The excess lifetime cancer (ELCR) values exceed the permissible limit. Therefore, the granitoids are unsuitable for use as infrastructure materials. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

A new regression model for bounded response variable: An alternative to the beta and unit-Lindley regression models.

A new distribution defined on (0,1) interval is introduced. Its probability density and cumulative distribution functions have simple forms. Thanks to its simple forms, the moments, incomplete moments and quantile function of the proposed distribution are derived and obtained in explicit forms. Four parameter estimation methods are used to estimate the unknown parameter of the distribution. Besides, simulation study is implemented to compare the efficiencies of these parameter estimation methods. More importantly, owing to the proposed distribution, we provide an alternative regression model for the bounded response variable. The proposed regression model is compared with the beta and unit-Lindley regression models based on two real data sets