Vol. 3 Issue 2
Gamal El- Ghazaly
Pollen morphology and floral micro characteristics as achene surface, filament collar and style form were investigated in 41 South American Hypochoeris species by LM and in certain cases, by SEM.
The studied species are divided into three well defined groups. It is proposed that one group viz. H. sessiliflora be separated from Hypochoeris as a distinct genus Oreophilia D. Don. Typified by D. Sessiliflora (Kunth) D. Don.
A. Mahmoud
Cassia italica, an evergreen under-shrub, is widely distributed in Saudi Arabia, and is used extensively as a medicinal plant. It is associated with depressions and water runnels. Germination was found to be dependent on scarification of the seed-coat, a process which could be achieved in the laboratory by acid treatment. The seeds germinated rapidly to high percentages over a wide range of alternating temperatures. Germination was also tested with various concentrations of seawater, under two fluctuating temperature regimes. The seeds germinated in salinities higher than those encountered by and tolerated by adult plants in their natural habitat.
H.A. Abulfatih and F.A. Bazzaz
Germination response of seeds of 15 wild species were tested on a temperature gradient. Growth rates of seedlings were evaluated at the optimum temperature for germination for each species. These species include 14 perennials and one annual found at various elevations between 20 and 2700 meters above sea level in the following order: Cassia italica, Salvadora persica, Calotropis procera, Datura innoxia (annual), Moringa peregrina, Lawsonia innermis, Abutilon pannosum, Acacia tortilis, Acacia ehrenbergiana, Acacia asak, Cucumis prophetarum, Coccinia grandis, Nepeta deflersiana, Verbascum nubicum, and Jasminum grandiflorum.
Seeds of most plants found at low elevation germinate best within a relatively narrow range of temperature at the warm end of the temperature gradient. Seeds collected from intermediate elevation show broader response to temperature and germinate at moderate temperature. Seeds collected from high elevation germinate best at low temperature. A relatively higher root/shoot ratio was recorded among plants of high elevation. Plants at different positions along the gradient showed different attributes indicating strategies for survival under the rather harsh and unpredictable environments at low and high altitudes. Among such attributes are rapid germination, germination under a broad range of temperature, germination in darkness, and high rate of root elongation.
M.O. Basalah, A.A.A. Suleiman and Sher Mohammad
Healthy and diseased leaves of Medicago sativa L. contained less reducing sugars, sucrose, polysaccharides and total carbohydrates than those of Tephrosia appolinea (Del.) Link. After infection by Uromyces striatus, total carbohydrates increased in both Medicago sativa and Tephrosia appolinea leaves and reducing sugars were unchanged. Sucrose content decreased in T. appolinea and increased in M. sativa. The activity of invertase was found to be greater than that of alpha-amylase in both plant leaves. Invertase activity increased and alpha-amylase activity decreased after rust infection in leaves of both plants. Increased invertase activity and decreased sucrose content on infection suggest the occurrence of either phloem unloading or decreased export of photosynthetic products.
Batoul Bashir Sirag, Abdel Rahman H. El Nadi and Iftikhar Ahmad
Rates and isomer distribution for the transformation of four N- chloramines to the nuclear substituted chloro anilines have been studied in acetic acid (99% v/v)., containing hydrochloric acid or toluene-p-sulfonic acid as promoters of the change. The reaction was found to be first order with respect to toluene-p-sulfonic acid and also first order with respect to N-chloro compound. The effect of hydrochloric acid concentration has also been studied and an explanation is put forward to account for the details of the course of the reaction.
Fatima S. Abulaban
The thermodependence of adenylate cyclase (AC) from rat uteri during Day 4 (D4) of early pseudopregnancy after trauma was studied using radiochemical analysis. AC activity, measured at 4- 55 degree Celsius exhibited maximal activity between 30-35 degree Celsius. In this temperature range, the enzyme activity varied between 16.60 + - 0.76 and 17.00 +- 0.33 picomoles cAMP per min per mg protein. An Arrhenius plot of the enzyme activity showed a single slop between 4-30 degree Celsius. The energy activation (Ea) was 15.94 +- 0.31 Kcal mol-1 deg-1 and the Q10(20-30) was 2.04 +- 0.02. Incubation of the non traumatized uteri with 10mM sodium fluoride exhibited a temperature optimum similar to that of the traumatized uteri. In this temperature range, AC activity varied between 18.64 +- 0.50 and 1839 +- 0.47 picomoles cAMP per min per mg protein. An Arrhenius plot of the AC activity exhibited a single slop between 4-30 degree Celsius. The Q10 (20-30) was 2.38 +- 0.04. These data suggest a similarity between decidual stimulation and sodium fluoride with respect to the activation of uterine adenylate cyclase
Patrick Sharrock and Samir Arabi
The reactivity of dinuclear iron complexes with bridging thiophenyl groups and various phosphorous donor ligands towards BF3 has been investigated.
Complexes containing BF3 were obtained by reaction of [uSC6H5Fe(CO)2L]2 with BF3. ET2O or with Cu(BF4)2.IR and HNMR provides strong evidence for a structure involving Fe2-BF3, a three-center donor-acceptor bond interaction.
Raja Hussein Abu- Samn
By the reaction of N.N'-dimethyl oxamide with water-free tin tetrachloride in the molar ratio (1:1), in hot pure 1, 2-dichloroethane as a solvent, a white powdery complex is obtained, where the bidentate ligand (N, N' -dimethyl oxamide) is bound to the central atom (Sn) of the prepared octahedral complex through the oxygen donors.
The synthesized complex is of the type SnCl4 LL. in which the coordination number of tin (4) in SnCl4 is increased to (6) in the complex.
The paper describes the preparation and properties of the complex and also includes its IR, H-NMR spectra, and the fragments of its mass spectrum.
Y. E. Abd Elhadi
The seismic inversion technique is a relatively novel method in exploration geophysics. The present paper discusses the methodology of this technique and illustrates its application to a specific problem in hydrocarbon exploration. the seismic inversion technique was applied in a recent digital seismic survey in the Abu Madi Gas Field, Egypt, in an attempt to delineate the reservoirs in that field and optimize their development.
High frequency as well as high amplitude seismic responses characterize thin gas-filled lenses, while low frequencies and high amplitudes characterize think sand lenses. The wavelet processes section demonstrated that the Abu Madi Formation is characterized by rapid lateral lithofacies changes which are related to the fluvio-deltaic depositional environment of these rocks. The wavelet- processes sections also showed that amplitude anomalies, which may be significant in terms of hydrocarbon potential, exist at deeper levels (Sidi Salem). Subsequently, deeper drilling has led to the discovery of new reservoir for gas and condensate accumulations.
Detailed velocity analysis from seismic data yielded highly stable velocity curves. The same results are observed in the borehole velocities. This indicates lithostratigraphic uniformity in the Abu Madi sedimentary section.
It is expected that seismic data collected with optimum unified-field parameters with increased high frequency content can provide even more useful results.
Abdulkader M. Abed
The Jordan Rift makes the northern segment of the East African- Red Sea Syrian Rift system in which the opening of the Gulf of Aden and the Red Sea is continuing here as a transcurrent movement. For other geologists, the Jordan Rift is a graben made by vertical tectonics which have been operating on this Rift since the Precambrian times. Their evidence is based on: (1) the distribution and abundance of dykes in the basement, (2) the distribution of Precambrian sediments and (3) the thickness and distribution of the Lower Cambrian Basal conglomerates. Careful field examination of these evidences showed that they are not well founded. Thus, casting more doubt on the weakened graben tectonic hypothesis.