Vol. 18 Issue 3
M.A.H. Al-Aawah and M.S. Al-Mohanadi
Benthic foraminifera from surface samples collected from the sea floor of Qatari waters, Arabian Gulf, were analyzed during this study. Thirty-nine species were identified and two foraminiferal assemblages were recognized. The Upper offshore assemblage is characterized by Quinqueloculina poeyana, Quinqueloculina peregrina, Quinqueloculina spp., Textularia cushmani, Textularia foliacea and Textularia spp. and occupies a water depth between 5 and 20m. The lower offshore assemblage is characterized by Quinqueloculina poeyana, Quinqueloculina pergina, Quinqueloculina spp. Ammonia beccarii, Cibicides cf. C. fletcheri and Eponides murrayi, and occupies a water depth more than 20 m. Benthic foraminiferal assemblages were more abundant and diverse in the lower offshore area then in the upper offshore area
V. Guberac, J. Martincic, S. Maric, D. Banaj, A. Opacak and D. Horvat
In the laboratory of the Faculty of Agriculture in Osijek (CROATIA), statistically highly significant correlations were found between storage longevity (five research years 1993- 1997) and seed germinability of soybean and fodder pea seeds. Seeds of the above mentioned species were stored in hermetic glass containers at air temperature of 20 °C and relative humidity 65%. Moisture level in stored seeds were 9%. The study showed that sprounting energy of soybean and fodder pea seeds was in negative correlation with storage longevity. Sprouting energy achieved the greatest values before seed storage (soybeans 90.50% and fodder peas 94.00%). After 5 years hermetic storage, sprouting energy achieved the smallest values (soybeans 13.25% and fodder peas 74.25%). The differences in sprouting energy found between the years were statistically highly significant (P<0.01).
Similar results were achieved by studying of seed germinability; the largest values of seed germinability were of the seeds before storage (95.75%). After 5 years hermetic storage, seed germinability achieved the smallest values (soybeans 15.50% and fodder peas 80.75%). The differences in seed germinability found between years were statistically highly significant (P<0.01).
According to the obtained results, seeds of fodder peas had greater values of sprouting energy and germinability than soybean seeds. The differences found between the species were statistically highly significant for sprouting energy (P<0.01) and significant for germinability (P<0.05).
M.A. Abdullah
The present work was conducted to study the effect of Calotropis procera and Zygophyllum simplex extracts on the 4th and 5th nymphal instars of the desert locust Schistocerca gregaria. The leaf extract of C. procera was significantly more effective on the the 4th and 5th nymphal instars than Z. simplex extract. The two plant extracts caused feeding inhibition with slightly increased nymphal duration. On the other hand, adult longevity was decreased and the preoviposition period of females was increased, particularly by increasing concentration of C. procera and Z. simplex extracts. Also these extracts affected different morphogenic abnormalities in the adult stages as will as nymphal instars
A.M. Gheith
The study was made in an attempt to differentiate between various modern environments using the natural surface features observed in quartz grains. Quartz grains from a number of recent environments (beach and nearshore, tidal flat and sabkha, coastal and inland dunes) were examined from Jeddah region.
Different information is available concerning occurrence and distribution of chemical and mechanical surface features and their relationship to the different environments.
Examination of quartz grain surface textures using the scanning electron microscope indicates that the transport and deposition in certain environments can be recognized by characteristic features.
M.M. Imam
Twelve samples containing charophytes were taken from Ar Rajban Member of Kiklah Formation of Wadi Ar Rajban surface section, Mizdah area, northwestern Libya. The study reveals well preserved charophyte assemblages that are closely associated with sandy to argillaceous limestone and calcareous siltstone samples. The lower part of the section yielded a charophyte assemblage that includes Porochara douzensis, P. palmeri, and P. maestricta of typically Late Jurassic age. On the other hand, the upper part yielded assemblages containing Atopochara trivolvis trivolvis, Flabellochara harrisi, Lamprothamnium cylindricum, and Porochara anluensis of definitely Early Cretaceous age. The recorded charophyte assemblages strongly indicated that the Ar Rajban Member was deposited under a lacustrine (fresh water) environment and represented ages from the Late Jurassic to the Early Cretaceous
A. Choukri
Subclinical mastitic milk presents a composition sensitively different from normal milk which could be reflected in milk products. Among the diagnostic methods of subclinical mastitic milk proposed, the enzymatic method (NAG-ase determination) and somatic cell count (SCC) are the most utilized. According to several authors, NAG-ase determination could be considered as one of the best to detect mastitic milk.
We present here a method for the determination of NAG-ase (N-Acetyl-B-D- glucosaminidase) activity in cow's milk. The analysis procedure was derived from that of Kitchen and Middleton (1976), where the precipitation, centrifugation and filtration steps were replaced by the transparization technique. A dissolving reagent was used at the end of the enzymatic reaction which rendered the medium transparent and thus could be directly read by spectrometer.
The reproducibility of the procedure was satisfactory and good correlations with a fluorimetric enzymatic method and somatic cell count were observed. Our results show that it is possible to classify milk according to its degree of infection while being based only on the activity of NAG-ase
Mansour A. Al-Hazmi
Lizards are important members of the desert fauna of Saudi Arabia. Uromastyx microlepis "Dhab" is one of the most dominant species in the central part of the country. The aims of the present study were to generate a baseline data on ecological behavioral, as well as the effect of human activities in relation to environmental changes in Dhab density under natural conditions. The distribution of Dhabs were studied in Central, North and Western region of Saudi Arabia by direct observation and counting Dhab numbers. Also the Dhab density in Al-Gassim region were recorded by dividing Al-Gassim to 14 sectors (provinces). The average density of Dhab in Al-Gassim region was estimated as 39/sq.km. Also Al-Ras province density was estimated as 132/sq.km. High numbers of Dhab were seen between 35-40 °C. Aleblah habitat was chosen for studying the effects of human activity on Dhab density and colony systems. The average density of Dhab in Aleblah was estimated as 49/sq.km. As a result of rapid developments in Al-Gassim Cities, Shab has shown a steadily decreasing range of colony system, distribution and declining density. The result of the present study had shown the necessity and had risen the awareness to conduct more conservational investigation on Dhab species, which are considered invaluable assets in the wildlife in Saudi Arabia
C. Viazminsky
A vector field L in a manifold M is incompressible if its divergence is equal to zero, i.e. if it satisfies the equation divL= 0. The solution of the last equation is well know in the three dimensional Euclidean space. In this work we determine a few expressions for an incompressible field in an n-dimensional Riemannian manifold M. Starting from one of these expressions, we show that every (n-1) functions of class C2 on M define an incompressible field whose lines are determined through setting these function equal to arbitrary constants. It is also shown that to every compressible field K there corresponds an infinite family of incompressible fields that have the same lines of K, but differ from K, as well as from each other, by their integral curves. The concept of "a compressibility removing factor" of a vector field K is introduced; it is defined as any function µ on M such that the field L = µK is incompressible. It is shown that the problem of determining the family of incompressible fields associated with the vector field K is equivalent to determining the family of compressibility removing factors of the field K. The quotient of two compressibility removing factors of field K is proven to be an integral of this field, and a general expression of the compressibility removing factors of the field K is derived. In case of a two-dimensional manifold, the relation between the compressibility removing factors of the field and the integrating factors of the ordinary differential equation associated with the field is found. The theory is illustrated through application to central fields. Finally, it is demonstrated that the set of all incompressible fields in a manifold M forms a sub-algebra of the Lie algebra formed by the set of all C(infinity) vector fields in M, and the sub-algebra of incompressible fields contains the set of Killing fields as a sub-algebra.