Staphylococci are common commensals in human beings, yet certain species are pathogenic. Staphylococcus aureus, particularly, is a very virulent human pathogen. The capacity of staphylococci to sense the density of bacterial cell, i.e., quorum, and thereafter respond via genetic modifications is attributable to one primary mechanism known as accessory gene regulator (Agr). Agr's extracellular signal is a peptide that is posttranslationally modified with a thiolactone molecule. Agr is in charge of the upregulation of numerous exotoxins and hydrolyzing enzymes, as well as the downregulation of many colonization determinants, under circumstances of high cell density. This modulation is critical for the scheduling synthesis of virulence determinants throughout the infection course and the establishment of acute illness, whereas low Agr activity is linked to persistent staphylococcal infections, such as biofilm development. Moreover, Staphylococcal Accessory Regulator Aِ (SarA) controls the establishment of biofilm in S. aureus that hinders the production of nuclease and protease via triggering the P2 and P3 promoters resulting in the activation of RNAII and RNAIII, respectively. SarA also endures the transcription of agrA and saeS, and many virulence determinants including hla, hlb, and hlg coding α-, β-, and γ-hemolysins, respectively. Upon the aforementioned facts, the present review will shed some light on the Quorum Sensing (QS) in S. aureus, particularly, the Agr and Sar systems and how these systems control the pathogenicity of this spe
The marshes are one of the important environmental features affecting human and animal systems, so the studying of changes they undergo is one of the important topics. This study is concerned with the changes occurring in the Al Saadya marsh for the period from 1987 to 2017 exclusively in the winter season (the marshes’ revival season in Iraq revive). In order to inspect the changes in this marsh, we choose 7 years to cover the study period as a criterion years, namely 1987, 1990, 1995, 2000, 2007, 2014 and 2017. The “Maximum Likelihood” classifier was used to separate the stacked land cover features, where the minimum overall accuracy ratio that recorded for all years of study was 96%. The results revealed that Al-Saadya marsh went t
... Show MoreIraq territory as a whole and south of Iraq in particular encountered rapid desertification and signs of severe land degradation in the last decades. Both natural and anthropogenic factors are responsible for the extent of desertification. Remote sensing data and image analysis tools were employed to identify, detect, and monitor desertification in Basra governorate. Different remote sensing indicators and image indices were applied in order to better identify the desertification development in the study area, including the Normalized difference vegetation index (NDVI), Normalized Difference Water Index (NDWI), Salinity index (SI), Top Soil Grain Size Index (GSI) , Land Surface Temperature (LST) , Land Surface Soil Moisture (LSM), and La
... Show MoreRemote sensing techniques used in many studies for classfying and measuring of wildfires. Satellite Landsat8(OLI) imagery is used in the presented work. The satellite is considered as a near-polar orbit, with a high multispectral resolution for covering Wollemi National Park in Australia. The work aims to study and measure wildfire natural resources prior to and throughout fire breakout which occurred in Wollemi National Park in Australia for a year (October, 2019), as well as analyzing the harm resulting from such wildfires and their effects on earth and environment through recognizing satellite images for studied region prior to and throughout wildfires. A discussion of methods for computing the affecred area i
... Show MoreA total of 37 Staphylococcus epidermidis isolates, isolated from corneal scraping of patients with bacterial keratitis and 20 isolates from healthy eyes (as control) (all isolates, isolated from, Ibn Al- Haietham eye hospital / Baghdad), were tested for slime production, 52.63% of all isolates were positive-slime production (23 isolates from patients and 7 isolates from controls). It was found that positive-slime producing S. epidermidis were exhibited a high resistance to antibiotics as compared to negative-slime producing isolates.
In this study the Individuals of Ostracoda crustacean Cyclocypria were used as bioclaner of two species of bacteria namely Escherichia coli & Staphylococcus aurous, these bacteria have been introduced to an artificial aquatic environment with known number from pure cultures. The aim was to check the predation efficiency and ecological role of Cyclocypria as biological cleaners. The results showed that the predation rate was between 6 106 × and 7× 10 6 colony/ ml/ 3 days/ 10 crustacean in the first three days. This rate increased remarkably in the 9th, 12th & 15th day from the beginning of the experiment and it was 10 × 10 6 and 15 × 10 6 respectively. &nb
... Show MoreThis work evaluated the effect of Alpha, Gamma irradiation and Nd:YAG, He-Ne laser on Staphylococcus epidermidis and Leishmania tropica in vitro. The experiment included five replicate of S. epidermidis , L. tropica in vitro exposed to effect of Alpha , Gamma irradiation by 241Am isotopes , in two doses
The research aims to monitor environmental changes and study the state of desertification in the northeastern part of the Al-Najaf province, Iraq. The study area suffers from desertification and drought phenomena. Remote sensing systems "RS" and geographic information systems "GIS" are essential for monitoring environmental changes because they provide Earth observation satellites that contribute to detecting environmental changes. Two Sentinel 2 images were acquired on December 26, 2015, and November 29, 2021. The images were combined and used for indices calculations. Normalized vegetation difference index "NDVI,” Normalized difference index "NDWI," soil exposure index "BSI," and Normalized difference index "NDBI." The resul
... Show MoreOne of the most important of satellite image is studying the surface water
according of its distribution and depth. In this work, three images have been taken
for Baghdad and surrounding for year (1991, 1999 and 2014) and by using of envi
program has been used. Different classes have been evaluated for Al-Habania and
Al-Razaza River according to its depth and water reflectance. In the present work
four types of water depth (very shallow, shallow, moderate, and deep area) have
been detected.
Nanostructural cupric oxide (CuO) films were prepared on Si and glass substrate by pulsed laser deposition technique (PLD) using laser Nd:YAG, using different laser pulses energies from 200 to 600 mJ. The X-ray diffraction pattern (XRD) of the films showed a polycrystalline structure with a monoclinic symmetry and preferred orientation toward (111) plane with nano structure. The crystallite size was increasing with increasing of laser pulse energy. Optical properties was characterized by using UV–vis spectrometer in the wave lengthrange (200-1100) nm at room temperature. The results showed that the transmission spectrum decreases with the laser pulses energy increase. Sensitivity of NO2 gas at different operating temperatures, (50°C,
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