University of Jordan

About: University of Jordan is a education organization based out in Amman, Jordan. It is known for research contribution in the topics: Population & Health care. The organization has 7796 authors who have published 13764 publications receiving 213526 citations.

Pathophysiological Mechanisms of Dominant and Recessive GLRA1 Mutations in Hyperekplexia

Abstract: Hyperekplexia is a rare, but potentially fatal, neuromotor disorder characterized by exaggerated startle reflexes and hypertonia in response to sudden, unexpected auditory or tactile stimuli. This disorder is primarily caused by inherited mutations in the genes encoding the glycine receptor (GlyR) α1 subunit (GLRA1) and the presynaptic glycine transporter GlyT2 (SLC6A5). In this study, systematic DNA sequencing of GLRA1 in 88 new unrelated human hyperekplexia patients revealed 19 sequence variants in 30 index cases, of which 21 cases were inherited in recessive or compound heterozygote modes. This indicates that recessive hyperekplexia is far more prevalent than previous estimates. From the 19 GLRA1 sequence variants, we have investigated the functional effects of 11 novel and 2 recurrent mutations. The expression levels and functional properties of these hyperekplexia mutants were analyzed using a high-content imaging system and patch-clamp electrophysiology. When expressed in HEK293 cells, either as homomeric α1 or heteromeric α1β GlyRs, subcellular localization defects were the major mechanism underlying recessive mutations. However, mutants without trafficking defects typically showed alterations in the glycine sensitivity suggestive of disrupted receptor function. This study also reports the first hyperekplexia mutation associated with a GlyR leak conductance, suggesting tonic channel opening as a new mechanism in neuronal ligand-gated ion channels.

Synthesis, chemistry, and spectroscopy of some tris(pentahaptocyclopentadienyl)uranium(IV) alkyl and aryl compounds

Abstract: Die thermisch stabilen Titelkomplexe (I) wurden durch Umsetzung von Chlorotris-[rr-cyclopentadienyl]-uran(IV) mit entsprechenden Li-Verbindungen bzw. Allylmagnesiumchlorid dargestellt und durch IR- und NMR-Spektren charakterisiert.

Spatial assessment of soil erosion risk using RUSLE and GIS techniques

Abstract: Soil erosion by water is considered a major cause for land degradation in Jordan, where 0.14 cm of productive top soil is eroded annually. This investigation is intended to estimate the annual soil loss in Wadi Kerak watershed, and to examine the spatial patterns of soil loss and intensity, as an essential procedure for proper planning of conservation measures. To achieve these objectives, the revised universal soil loss equation (RUSLE) model has been applied in a geographical information system framework. After computing the RUSLE parameters (R, K, LS, C and P) soil erosion risk and intensity maps were generated, then integrated with physical factors (terrain units, elevation, slope, and land uses/cover) to explore the influence of these factors on the spatial patterns of soil erosion loss. The estimated potential annual average soil loss is 64 ton ha−1year−1, and the potential erosion rates from calculated class ranges from 0.0 to 790 ton ha−1year−1. Soil erosion risk assessment indicates that 54.5 % of the catchment is prone to high to extreme soil losses higher than 25 ton ha−1year−1. The lower and middle parts of the catchment suffer from high, severe, to extreme soil erosion. While 45.5 % of the basin still undergoes slight and moderate levels of soil loss of less than 25 ton ha−1year−1, yet 76.91 % of soil erosion occurred on four different terrain units, and 72.29 % of soil erosion occurred in zones less than 600 m in elevation, with 88 % present on areas of 0°–6°, 5°–15°, and 15°–25° slope categories. 32.6, 30.3, and 33.1 % of soil erosion occurred on rainfed mixed farming and irrigated areas, barren, and rangeland, respectively. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable agriculture in the highland region of Jordan.