8 research outputs found
Voltage stability assessment for distrbuted generation in islanded microgrid system
The increasing energy demands are stressing the generation and transmission
capabilities of the power system. Distributed generation (DG), which generally
located in distribution systems, has the ability to meet some of the growing energy
demands. However, unplanned application of individual distributed generators might
cause other technical problems. The microgrid concept has the potential to solve
major problems arising from large penetration of DG in distribution systems. A
microgrid is not a forceful system when it is compared to a power system. This
project proposes a simulation approach to study voltage stability index (VSI) and
voltage stability analysis in microgrid system for the improvement of the dynamic
voltage stability in a microgrid in case of the dynamic voltage insufficiency. A
model of IEEE-14 Bus System has been presented as a case study of an islanded
microgird system. This project also presented line voltage stability index analysis
which accurately performs voltage stability analysis at each transmission line and
precisely predicts voltage collapse on power systems. A formula to calculate VSI has
been derived and applied on two cases on the system. To show the effectiveness of
the proposed voltage stability analysis method, this approach is implemented in a
microgrid test system (14-bus, 20 lines) in PSAT which is a MATLAB toolbox
environment. The test system has four diesel DGs and a wind turbine connected with
eleven constant loads. The dynamic simulation of the test system is carried out for
various types of disturbances. Islanded mode of operation is considered in this study.
Fast Voltage Stability Index (FVSI) and voltage stability analysis have been
successfully implemented and analysed
Molecular characteristics and zoonotic potential of enteric protists in domestic dogs and cats in Egypt
Introduction: Domestic dogs and cats can be a source of human infection by a wide diversity of zoonotic pathogens including parasites. Genotyping and subtyping tools are useful in assessing the true public health relevance of canine and feline infections by these pathogens. This study investigated the occurrence, genetic diversity, and zoonotic potential of common diarrhea-causing enteric protist parasites in household dogs and cats in Egypt, a country where this information is particularly scarce. Methods: In this prospective, cross-sectional study a total of 352 individual fecal samples were collected from dogs (n = 218) and cats (n = 134) in three Egyptian governorates (Dakahlia, Gharbeya, and Giza) during July-December 2021. Detection and identification of Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, and Blastocystis sp. were carried out by PCR and Sanger sequencing. Basic epidemiological variables (geographical origin, sex, age, and breed) were examined for association with occurrence of infection by enteric protists. Results and discussion: The overall prevalence rates of Cryptosporidium spp. and G. duodenalis were 1.8% (95% CI: 0.5-4.6) and 38.5% (95% CI: 32.0-45.3), respectively, in dogs, and 6.0% (95% CI: 2.6-11.4) and 32.1% (95% CI: 24.3-40.7), respectively, in cats. All canine and feline fecal samples analyzed tested negative for E. bieneusi and Blastocystis sp. Dogs from Giza governorate and cats from Dakahlia governorate were at higher risk of infection by Cryptosporidium spp. (p = 0.0006) and G. duodenalis (p = 0.00001), respectively. Sequence analyses identified host-adapted Cryptosporidium canis (n = 4, one of them belonging to novel subtype XXe2) and G. duodenalis assemblages C (n = 1) and D (n = 3) in dogs. In cats the zoonotic C. parvum (n = 5) was more prevalent than host-adapted C. felis (n = 1). Household dogs had a limited (but not negligible) role as source of human giardiasis and cryptosporidiosis, but the unexpected high frequency of zoonotic C. parvum in domestic cats might be a public health concern. This is the first molecular-based description of Cryptosporidium spp. infections in cats in the African continent to date. Molecular epidemiological data provided here can assist health authorities and policy makers in designing and implementing effective campaigns to minimize the transmission of enteric protists in Egypt.This study was partially funded by the Health Institute Carlos III (ISCIII), Spanish Ministry of Economy and Competitiveness under project PI19CIII/00029. This study was supported by Researchers Supporting Project number (RSPD2023R655), King Saud University, Riyadh, Saudi ArabiaS
Molecular detection and characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi infections in dromedary camels (Camelus dromedaries) in Egypt
IntroductionFew studies have investigated the occurrence of microeukaryotic gut parasites in dromedary camels in Egypt, and the majority of these investigations are based on microscopic analysis of fecal material.MethodsHerein, we assessed the occurrence, molecular diversity, and zoonotic potential of protozoan (Cryptosporidium spp. and Giardia duodenalis) and microsporidian (Enterocytozoon bieneusi) pathogens in individual fecal samples (n = 102) of dromedary camels with (n = 26) and without (n = 76) diarrhea from Aswan Governorate, Upper Egypt. Other factors possibly associated with an increased risk of infection (geographical origin, sex, age, and physical condition) were also analyzed. The SSU rRNA or ITS genes were targeted by molecular (PCR and Sanger sequencing) techniques for pathogen detection and species identification.Results and discussionThe most abundant species detected was G. duodenalis (3.9%, 4/102; 95% CI: 1.1–9.7), followed by Cryptosporidium spp. (2.9%, 3/102; 95% CI: 0.6–8.4). All samples tested negative for the presence of E. bieneusi. Sequence analysis data confirmed the presence of zoonotic C. parvum (66.7%, 2/3) and cattle-adapted C. bovis (33.3%, 1/3). These Cryptosporidium isolates, as well as the four Giardia-positive isolates, were unable to be amplified at adequate genotyping markers (Cryptosporidium: gp60; Giardia: gdh, bg, and tpi). Camels younger than 2 years old were significantly more likely to harbor Cryptosporidium infections. This connection was not statistically significant, although two of the three cryptosporidiosis cases were detected in camels with diarrhea. The spread of G. duodenalis infections was unaffected by any risk variables studied. This is the first report of C. parvum and C. bovis in Egyptian camels. The finding of zoonotic C. parvum has public health implications since camels may function as sources of oocyst pollution in the environment and potentially infect livestock and humans. Although preliminary, this study provides useful baseline data on the epidemiology of diarrhea-causing microeukaryotic parasites in Egypt. Further research is required to confirm and expand our findings in other animal populations and geographical regions of the country
Comparative Effect of Allicin and Alcoholic Garlic Extract on the Morphology and Infectivity of Eimeria tenella Oocysts in Chickens
Avian coccidiosis remains one of the major parasitic diseases that threaten the global poultry industry. Since prevention is superior to treatment, this study focuses on eliminating the infection outside the host. To determine their effect on the viability of Eimeria tenella oocysts in vitro, allicin and alcoholic garlic extract, which are natural, less toxic, and inexpensive products, were compared to KOH 5% (chemical disinfectant) using an in vitro culture system. Three concentrations of allicin (45, 90, and 180 mg/mL) and alcoholic garlic extract (90, 180, and 360 mg/mL, were used. Subsequently, destructive and sporulation-inhibiting effects on Eimeria oocysts were detected using light and electron microscopy. Young chickens were infected with treated sporulated oocysts to determine their effect on infectivity. After 7 days pi, the percentage of excreted oocysts (oocyst shedding) was determined, and the chickens were slaughtered for histopathological examination of the cecal tissues. Under an electron microscope, allicin at a concentration of 180 mg/mL and alcoholic garlic extract at a concentration of 360 mg/mL demonstrate a high oocysticidal activity with severe destruction of the oocyst wall and the appearance of pores. In addition, both concentrations directly affected the infectivity of sporulated oocysts by reducing the shedding of oocysts and the pathological lesions of infected young chickens. We concluded that the ability of Allicin and alcoholic garlic extract to eliminate Eimeria oocysts makes them superior to chemical disinfectants as a disinfectant
Data_Sheet_1_Molecular identification of Haemonchus contortus in sheep from Upper Egypt.ZIP
IntroductionHaemonchus spp. are considered the most important strongylid nematodes with a worldwide distribution. The parasite’s blood-sucking nature can lead to severe anemia in infected animals. Despite its widespread impact, there is a dearth of comprehensive data on morphological and molecular identification methods for Haemonchus spp. in sheep from Upper Egypt. To address this gap, our current study aimed to assess the prevalence of Haemonchus spp. in 400 sheep fecal samples.MethodsWe employed microscopic examination and molecular techniques, using polymerase chain reaction (PCR) targeting the 18S gene for precise identification. Additionally, the potential risk factors associated with the infection by the parasite in sheep were explored.ResultsThe study pointed out that 33.00% (132 of 400) of the examined sheep were infected with Haemonchus spp. Sheep age and seasonal variability were found to be significant factors (p 0.05) was found between the sex of the examined sheep and the occurrence of haemonchosis. Employing molecular methods, we isolated and identified the parasite through PCR analysis of cultured larvae, which were then subsequently confirmed as Haemonchus contortus via phylogenetic analysis.DiscussionThe study concluded that there was a relatively high occurrence of H. contortus among sheep from Upper Egypt. We recommend the implementation of stringent and effective control measures to combat the infection and safeguard livestock health.</p
Wheat Germ Oil and Propolis Decrease Parasite Burden and Restore Marked Histopathological Changes in Liver and Lung in Mice with Chronic Toxoplasmosis
Toxoplasmosis is a parasitic zoonotic disease with a worldwide distribution. Its effects can be critical in immunocompromised patients. However, there is a limited availability of effective, low-toxicity drugs against this disease, particularly in its chronic form. The present study evaluated the effect of propolis and wheat germ oil (WGO) as safe, natural products to reduce Toxoplasma cysts in experimentally infected mice. For the experiment, five groups (10 mice per group) were examined: Group 1: negative control (noninfected, nontreated); Group 2: positive control (infected, nontreated); Group 3: infected and treated with WGO at a dose of 0.2 mg/1.5 mL per kg body weight/day; Group 4: infected and treated with 0.1 mL propolis extract/day; and Group 5: infected and treated with a combination of WGO and propolis at the same doses as Group 3 and 4. After the mice were sacrificed, liver and lung specimens underwent histopathological examination, and the parasite burden was investigated by parasitological methods and quantified using real-time polymerase chain reaction. Notably, the results showed a substantial decrease in parasitic burden in Group 5 compared to the control group. These results were further confirmed by molecular analysis and quantification of the DNA concentration of the Toxoplasma P29 gene after treatment in all tested samples. Furthermore, the combination of propolis and WGO restored all histopathological changes in the liver and lungs. Taken together, these findings provide remarkably promising evidence of the effects of the combination of WGO and propolis against chronic toxoplasmosis in mice
Data_Sheet_1_Molecular detection and characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi infections in dromedary camels (Camelus dromedaries) in Egypt.PDF
IntroductionFew studies have investigated the occurrence of microeukaryotic gut parasites in dromedary camels in Egypt, and the majority of these investigations are based on microscopic analysis of fecal material.MethodsHerein, we assessed the occurrence, molecular diversity, and zoonotic potential of protozoan (Cryptosporidium spp. and Giardia duodenalis) and microsporidian (Enterocytozoon bieneusi) pathogens in individual fecal samples (n = 102) of dromedary camels with (n = 26) and without (n = 76) diarrhea from Aswan Governorate, Upper Egypt. Other factors possibly associated with an increased risk of infection (geographical origin, sex, age, and physical condition) were also analyzed. The SSU rRNA or ITS genes were targeted by molecular (PCR and Sanger sequencing) techniques for pathogen detection and species identification.Results and discussionThe most abundant species detected was G. duodenalis (3.9%, 4/102; 95% CI: 1.1–9.7), followed by Cryptosporidium spp. (2.9%, 3/102; 95% CI: 0.6–8.4). All samples tested negative for the presence of E. bieneusi. Sequence analysis data confirmed the presence of zoonotic C. parvum (66.7%, 2/3) and cattle-adapted C. bovis (33.3%, 1/3). These Cryptosporidium isolates, as well as the four Giardia-positive isolates, were unable to be amplified at adequate genotyping markers (Cryptosporidium: gp60; Giardia: gdh, bg, and tpi). Camels younger than 2 years old were significantly more likely to harbor Cryptosporidium infections. This connection was not statistically significant, although two of the three cryptosporidiosis cases were detected in camels with diarrhea. The spread of G. duodenalis infections was unaffected by any risk variables studied. This is the first report of C. parvum and C. bovis in Egyptian camels. The finding of zoonotic C. parvum has public health implications since camels may function as sources of oocyst pollution in the environment and potentially infect livestock and humans. Although preliminary, this study provides useful baseline data on the epidemiology of diarrhea-causing microeukaryotic parasites in Egypt. Further research is required to confirm and expand our findings in other animal populations and geographical regions of the country.</p