Particulate matter characterization and control in premixed compression ignition engines

The tests were conducted on a 2.2 L, four-cylinder Ford Puma engine running on a Premixed Compression Ignition (PCI) mode and at steady state. Hot EGR was introduced for fuels, G75 and naphtha and it significantly reduced the total particle number and mass concentrations by about 99% and the mean diameter to a smaller size ~ 10 nm compared to diesel fuel. Single injection reduced the total particle numbers’ concentration and smoke of both fuels G75 and naphtha by about 99%. Also, the total carbon (TC) was reduced by more than 54% for G75 and naphtha fuels compared to diesel fuel. The double injection strategy was flexible than the single injection. It reduced the total particle numbers’ concentration and smoke of G75 and naphtha fuels by about 99.80% at low and medium loads, also the total concentration of PAHs was reduced by more than 90% compared to single injected diesel fuel. For G75 fuel, double injection reduced the total concentration of alkanes by 60%, while single injection reduced the total concentration of cycloalkanes by 54% compared to other fuels

Early-onset Evans syndrome in a 4-month-old infant: A case report and review of literature

Evans syndrome (ES) is a rare autoimmune disorder characterized by autoimmune hemolytic anemia (AIHA) and immune thrombocytopenic purpura (ITP). We report a case of a 4-month old infant who presented with a history of acute pallor and jaundice. She had no family history of any hematological or autoimmune disorders. Her laboratory investigations revealed a positive direct Coombs test with immunoglobulin G autoantibodies, anemia and thrombocytopenia. She was managed initially by blood transfusion and started on high-dose steroid therapy with marked improvement. Very few cases of ES in infants have been reported in the literature. We concluded that this case report may support the possibility of an early-onset ES among infants <6 months of age

Structural Relationships between Learning Emotion and Knowledge Organization and Management Processes in Distance Learning Environments: “An Applied Study”

The widespread adoption and expansion of distance learning necessitates the consideration of issues related to learning passion, which is the strong desire of learners towards a specific activity of high value and meaning that enables the use of relevant cognitive and behavioral strategies to acquire, store, apply, share, use, absorb, and create knowledge. The current study aimed to measure learners’ practices of learning emotion processes, knowledge management, and organization in distance learning environments using tangible indicators. The study utilized a descriptive correlational approach to identify the effects of the study variables, including learning emotion (harmonious passion—emotional obsession), on knowledge management through the mediating role of self-regulation in distance learning environments. The results show that learners’ practices of learning emotion processes, knowledge management, and organization in distance learning environments were higher than average, and there was a significant correlation between emotion, self-regulation, and knowledge management. Additionally, learning emotion (harmonious passion and emotional obsession) had a statistically significant effect on self-organization processes and knowledge management. Structural equation modeling analysis confirmed the validity of the proposed path model, indicating that self-regulation plays a crucial role in mediating the relationship between emotion and knowledge management in distance learning environments

Hydrolytic Enzyme Production by Thermophilic Bacteria Isolated from Saudi Hot Springs

Hydrolytic enzyme production by thermophilic bacteria isolated from hot springs in the southern region of Saudi Arabia was investigated. The physical and chemical properties of the hot springs prove to be an important environment for hydrolytic-enzyme-producing thermophilic bacteria. Eighty-four bacterial isolates were obtained from three hot springs: Al-Majardah, Al-Khubah and Al-Ardah. Screening of the isolates for enzyme production indicated that 78 isolates showed activity for one or more enzymes. Molecular identification and phylogenic analysis of selected promising isolates confirmed the identity of the isolates as Bacillus aerius, Bacillus licheniformis and Bacillus sonorensis, which have potential to produce the target enzymes α-amylase, protease and lipase, respectively. Optimization of hydrolytic enzyme production by bacterial strains was investigated using kitchen waste as a cheap carbon energy source. Maximum enzyme production was achieved after 72 hours of incubation at the beginning of the stationary phase of growth. Enzyme production was dependent on the initial pH value in the range of pH 7.5-8.5 and an optimal incubation temperature of between 55-60°C. Enzyme production increased gradually in proportion to the kitchen waste concentration; whereas maximum lipase production was gained at 5.0% (w/v) kitchen waste, 7.0% (w/v) of waste was optimal for both α-amylase and protease productivity. The results indicated that hot springs in Saudi Arabia are a substantial source of thermophilic bacteria producing industrially important enzymes using cheap and unexploited waste

Molecular Characterization of Leishmania Species among Patients with Cutaneous Leishmaniasis in Asir Province, Saudi Arabia

Anthroponotic cutaneous leishmaniais (ACL) and zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania tropica and Leishmania major, respectively, are endemic vector-borne diseases in southern Saudi Arabia. In 2021, an outbreak of cutaneous leishmaniasis occurred in the province of Asir. The main objective of our investigation was to analyze the epidemiological features of CL in southern Saudi Arabia. The ministry of health recorded 194 CL patients between January and December 2021 from the Asir province. Our findings showed that the majority of CL patients (87.1%) originated from the governorates of Khamis-Mushait and Abha. Most of the patients were males (62.3%). While CL affected all age groups, those under 13 years old were the most affected (38.1%). For both genders, CL patients were mostly Saudi citizens (90.7%) compared to non-Saudi expatriates. The majority of CL patients (75.2%) suffered from a single lesion, and the majority of lesions (61.3%) were located on the face. The seasonal prevalence of CL showed two peaks, a small one in July&ndash;August and a larger one in March. Of a total of 194 Giemsa slides samples, 188 showed positive amplification of Leishmania ITS1 gene. Based on PCR-RFLP and PCR-HMR, 183 patients showed positive amplification of L. tropica and five patients showed positive amplification of L. major. Phylogenetic analysis revealed a clear distinct separation between L. major and L. tropica sequences. Our results provided strong evidence of the pre-domination of L. tropica, the main etiological agent of ACL in Asir province. We reported for the first time the presence of L. major, an etiological agent of ZCL in the study areas. The co-circulation of ACL and ZCL highlighted the complexity of the epidemiology of CL in southern Saudi Arabia, and subsequently, further studies to identify competent vectors and reservoir hosts for the establishment of control strategies are needed