Constructing a criterion-referenced test in psychometric subjects according to item response theory

The article aimed to construct criterion-referenced in the psychometric subject based on item response theory. The sample consisted of (121) participants (54 male & 67 female) selected from the Department of Psychology at Isra University (Jordan) during the second semester of the academic year 2021/2022. The criterion-referenced test consisted of (36) items following a multiple-choice shape in which each item has 4 options. The results showed the assumptions of items response theory in the study data and matched the responses to (34) items. The results found that there were two items that did not match the model of item response theory that were deleted. Finally, the results of the parameter assessments of the items (discrimination, difficulty, and estimation) indicated that they were agreeable with the test criteria mentioned in psychometric literature and educational. In light of the results obtained, the study recommended using the test, which was developed by the researchers to assess student’s achievement in the subject of psychometrics for students of Psychology, because it demonstrates acceptable validity and reliability and complies with the requirements of the logarithmic three-parameter model, and the possibility of using the same methods as assessments for other courses after ensuring their psychometric qualities

Bacterial lipid II analogs : novel in vitro substrates for mammalian oligosaccharyl diphosphodolichol diphosphatase (DLODP) activities

Mammalian protein N-glycosylation requires the transfer of an oligosaccharide containing 2 residues of N-acetylglucosamine, 9 residues of mannose and 3 residues of glucose (Glc3Man9 GlcNAc2) from Glc3Man9GlcNAc2-diphospho (PP)-dolichol (DLO) onto proteins in the endoplasmic reticulum (ER). Under some pathophysiological conditions, DLO biosynthesis is perturbed, and truncated DLO is hydrolyzed to yield oligosaccharyl phosphates (OSP) via unidentified mechanisms. DLO diphosphatase activity (DLODP) was described in vitro, but its characterization is hampered by a lack of convenient non-radioactive substrates. Our objective was to develop a fluorescence-based assay for DLO hydrolysis. Using a vancomycin-based solid-phase extraction procedure coupled with thin layer chromatography (TLC) and mass spectrometry, we demonstrate that mouse liver membrane extracts hydrolyze fluorescent bacterial lipid II (LII: GlcNAc-MurNAc(dansyl-pentapeptide)-PP-undecaprenol) to yield GlcNAc-MurNAc(dansyl-pentapeptide)-P (GM5P). GM5P production by solubilized liver microsomal proteins shows similar biochemical characteristics to those reported for human hepatocellular carcinoma HepG2 cell DLODP activity. To conclude, we show, for the first time, hydrolysis of lipid II by a eukaryotic enzyme. As LII and DLO are hydrolyzed by the same, or closely related, enzymes, fluorescent lipid II analogs are convenient non-radioactive substrates for investigating DLODP and DLODP-like activities

Oligosaccharide Diphosphodolichol (DLO) Diphosphatase : un régulateur potentiel des DLO

CONTEXTE: Les " Type I Congenital disorders of glycosylation " (CDG-I) comportent des déficits de biosynthèse de l'oligosaccharide lié au dolichol (DLO) qui est nécessaire pour la N-glycosylation des protéines. Ces déficits induisent : 1) une hypoglycosylation des protéines qui serait à l'origine de la pathologie ; et 2) une accumulation de DLO tronqués à partir desquels, par un mécanisme encore inconnu, des structures oligosaccharidiques libres phosphorylées (OSP) sont générées dans le cytosol. Afin de comprendre le rôle de ce processus dans le CDG, il était donc nécessaire de caractériser l'activité qui est à l'origine des OSP.RESULTATS: J'ai caractérisé biochimiquement une DLO diphosphatase (DLODP) qui génère des OSP et du dolichol phosphate à partir de DLO. L'activité DLODP co-fractionne avec un marqueur de l'appareil de Golgi (AG) mais pas avec les enzymes réticulaires qui utilisent le dolichol phosphate. Cette localisation inattendue de DLODP m'a conduit à étudier la génération des OSP dans les cellules en utilisant la bréfeldine A (BFA) qui fusionne l'AG avec le RE. La BFA ne modifie pas les taux de DLO tronqués ni ceux des OSP cytoplasmiques dans un modèle cellulaire de CDG-I. Cependant, dans ces cellules et dans les cellules témoins, la BFA induit une forte augmentation des OSP dans le système endomembranaire à partir de DLO non-tronqués.CONCLUSION: L'identification de différents pools d'OSP, topologiquement distincts et pouvant être modulés de façon indépendante, révèle la multiplicité des mécanismes pour la génération d'OSP et suggère que la DLODP Golgienne n'est pas forcément l'enzyme responsable de la génération des OSP dans le contexte de CDG-I.BACKGROUND: Type I congenital disorders of glycosylation (CDG-I) are caused by genetic defects in the biosynthetic pathway for the dolichol-linked oligosaccharide (DLO) that is required for protein N-glycosylation. These mutations result in the accumulation of truncated DLO and protein hypoglycosylation. Although protein hypoglycosylation is thought to be the main pathogenic factor in CDG-I, the role of truncated DLO intermediates in cellular homeostasis is not clear. Truncated DLO intermediates are known to give rise to cytoplasmic oligosaccharyl phosphates (OSP) by an uncharacterized mechanism. To understand this DLO editing process biochemical and molecular characterization of the activity that generate OSP is needed.RESULTS: I biochemically characterized a DLO diphosphatase (DLODP) that generates OSP and dolichol phosphate from DLO. Subcellular fractionation of mouse liver homogenates demonstrated a microsomal activity that co-distributes with a Golgi apparatus (GA) marker but not with endoplasmic reticulum (ER)-situated dolichol phosphate utilizing enzymes. This unexpected localization of DLODP prompted me to study OSP generation in cells using brefeldin A (BFA), which fuses the GA with the ER. BFA did not affect the levels of truncated DLO or cytoplasmic OSP, present in a cellular model of CDG-I. However, in these, and control cells, BFA caused striking increases of OSP within the endomembrane system. CONCLUSION: the identification of topologically distinct, independently modulated, OSP pools indicates multiple mechanisms for OSP generation and suggest that the GA-situated DLODP may not be the enzyme responsible for OSP generation in CDG-I

Adolescents' Use of Social Networking Sites and Its Impact on Family and Social Relations from Their Viewpoint in Jordanian Society

This study aimed to identify adolescents' use of social networking sites and its impact on the family and social relationship from their viewpoint in Jordanian society, the analytical descriptive approach was used, and the questionnaire was used to collect data. The study sample consisted of (1534) adolescents; were chosen randomly, the results of the study found that the general arithmetic mean as a whole for the impact of the use of social networking sites by adolescents on family relations was (2.73), with a medium degree, where parents' refusal to publish children's pictures on social networking sites was ranked first with a rate of 3.17, but after knowing the effect of using social networking sites by adolescents on social relations, the general arithmetic mean as a whole was 3.34, and with a medium degree, where the feeling of comfort while visiting friends and relatives came in the first place with a percentage of (3.54), it also found that there are statistically significant and differences in the arithmetic means according to the gender variable, in favor of males with an arithmetic mean of (2.89), and there are statistically significant differences according to the variable of place of residence, in favor of the city, with an arithmetic mean (2.80), and there are statistically significant differences in the arithmetic averages according to the monthly income of the family. Keywords: Adolescents, Social Networking Sites, Family And Social Relations, Jordanian Society. DOI: 10.7176/JEP/15-1-01 Publication date: January 31st 202

Synthesis and biological evaluation of chemical tools for the study of Dolichol Linked Oligosaccharide Diphosphatase (DLODP).

International audienceCitronellyl- and solanesyl-based dolichol linked oligosaccharide (DLO) analogs were synthesized and tested along with undecaprenyl compounds for their ability to inhibit the release of [(3)H]OSP from [(3)H]DLO by mammalian liver DLO diphosphatase activity. Solanesyl (C45) and undecaprenyl (C55) compounds were 50-500 fold more potent than their citronellyl (C10)-based counterparts, indicating that the alkyl chain length is important for activity. The relative potency of the compounds within the citronellyl series was different to that of the solanesyl series with citronellyl diphosphate being 2 and 3 fold more potent than citronellyl-PP-GlcNAc2 and citronellyl-PP-GlcNAc, respectively; whereas solanesyl-PP-GlcNAc and solanesyl-PP-GlcNAc2 were 4 and 8 fold more potent, respectively, than solanesyl diphosphate. Undecaprenyl-PP-GlcNAc and bacterial Lipid II were 8 fold more potent than undecaprenyl diphosphate at inhibiting the DLODP assay. Therefore, at least for the more hydrophobic compounds, diphosphodiesters are more potent inhibitors of the DLODP assay than diphosphomonoesters. These results suggest that DLO rather than dolichyl diphosphate might be a preferred substrate for the DLODP activity

Prevalence and associated risk factors of tinnitus among adult Palestinians: a cross-sectional study

Abstract Tinnitus is a common complaint with potentially negative impact on quality of life. Prevalence of tinnitus ranges from 5 to 43% worldwide. This variation could be due to the heterogeneity of tinnitus assessment. This has limited the progress in understanding tinnitus. Therefore, we employed a standardized and a validated assessment method to determine the prevalence and related risk factors of tinnitus among Palestinians for the first time. This is a cross-sectional study in which we questioned a representative sample of 618 subjects in one-to-one interviews. The prevalence of any tinnitus was 30.6% among adult Palestinians. Participants from the oldest age group were almost five times more likely to have tinnitus. Moreover, participants with head and neck pain syndrome, severe hearing impairment, sleeping disorders or frequent complaints of vertigo were approximately two times more likely to have tinnitus. Our study provides novel information regarding tinnitus in Palestine and improves our understanding of tinnitus. This will improve the diagnosis and consequently will contribute in reducing the prevalence and perhaps in preventing tinnitus. As tinnitus still has no known cure, further investigations of modifiable risk factors and causes of tinnitus are crucial to prevent it in the future