Showing papers by "Cairo University published in 1984"
TL;DR: A new solution to the image segmentation problem that is based on the design of a rule-based expert system that dynamically alters the processing strategy is presented.
Abstract: A major problem in robotic vision is the segmentation of images of natural scenes in order to understand their content. This paper presents a new solution to the image segmentation problem that is based on the design of a rule-based expert system. General knowledge about low level properties of processes employ the rules to segment the image into uniform regions and connected lines. In addition to the knowledge rules, a set of control rules are also employed. These include metarules that embody inferences about the order in which the knowledge rules are matched. They also incorporate focus of attention rules that determine the path of processing within the image. Furthermore, an additional set of higher level rules dynamically alters the processing strategy. This paper discusses the structure and content of the knowledge and control rules for image segmentation.
380 citations
TL;DR: The etiology and surgical repair of aponeurotic hernial defects were restudied on a structural-functional biomechanical basis and the mechanism of herniation through the anterior abdominal wall ap oneuroses remains inadequately explained.
73 citations
TL;DR: Finds at a Late Paleolithic site at Wadi Kubbaniya in Egypt suggest an early origin of food production, with implications for the initial development of complex societies.
Abstract: In 1978, three carbonized grains of barley and a carbonized grain of einkorn wheat were found in a buried hearth at a Late Paleolithic site at Wadi Kubbaniya in Egypt. In 1981, two large clusters of barley seeds, which were identified as six-row barley and thus domestic, were found at a nearby site of comparable age. Numerous grinding stones, presumed to have been used for processing the cereals, were found in these and other sites, often deeply buried, and 30 radiocarbon dates placed the occupations between 18,500 and 17,000 radiocarbon years ago. These finds led us to suggest an early origin of food production, with implications for the initial development of complex societies. Several barley seeds were analyzed by electron spin resonance spectroscopy to determine the maximal temperature to which they had been subjected before burial. Six barley seeds and three small pieces of wood charcoal were dated directly by using a tandem accelerator mass spectrometer.
66 citations
TL;DR: In this paper, the orientations in these reactions are interpreted in terms of the Frontier Molecular Orbital theory, and the structures of the products 3, 5 and 6 were substantiated by their chemical reactions and alternate synthesis wherever possible.
51 citations
TL;DR: An ethanol extract of Aristolochia indica roots decreased fertility in both rats and hamsters when administered postcoitally and cis- and trans-p-coumaric acid (both oblate commercially) were similarly tested in mice and found to be inactive.
Abstract: An ethanol extract of Aristolochia indica roots decreased fertility in both rats and hamsters when administered postcoitally (days 1-10 and 1-6, respectively). Petroleum ether (A), CHCl3 (B), and aqueous (C) fractions, tested similarly in rats, were inactive and/or toxic. Partition of fraction B afforded non-acidic (D) and acidic (E) fractions. Savinin (1), isolated from fraction D and not previously reported from the Aristolochiaceae , was inactive when administered postcoitally to rats. Aristolochic acid-I (2), reported previously from A. indica and isolated from fraction E, was inactive when administered postcoitally to rats and toxic when administered postcoitally to hamsters. (12S)-7,12- Secoishwaran -12-ol (3), previously reported from A. indica and isolated from fraction A, did not interrupt pregnancy when administered to mice on day 6 of pregnancy. Four additional compounds, aristolic acid (4) [prepared from aristolochic acid-I (2)], methyl aristolate (5) [prepared by methylating aristolic acid (4)], and cis- and trans-p-coumaric acid (both oblate commercially), were similarly tested in mice and found to be inactive. Aristolic acid (4), and the cis- and trans-p-coumaric acids also were inactive when administered postcoitally (days 1-10) to rats. Seven compounds reported previously from A. indica were also isolated, as were a new naphthoquinone, aristolindiquinone (6) (fraction E), and magnoflorine (fraction C).
47 citations
TL;DR: In this paper, the effect of soil inoculation with a selected strain of the silicate bacteria Bacillus circulans on the release of K and Si from difficult minerals was investigated.
43 citations
TL;DR: A double-sphincter mechanism controlling the continence of pelvic organs is presented with a role-description of the involved pelvic musculature and the different types of incontinence are outlined.
38 citations
TL;DR: Gamogony and sporogony of Culex pipiens molestus were studied in the haemocoel of its vector by electron microscopy on day 2 pi, the parasites, associated in pairs, grew large and differentiated into micro- and macrogamonts within the same parasitophorous vacuole as mentioned in this paper.
Abstract: Gamogony and sporogony ofH aegypti were studied in the haemocoel of its vectorCulex pipiens molestus by electron microscopy On day 2 pi, the parasites, associated in pairs in the haemocoel, grew large and differentiated into micro- and macrogamonts within the same parasitophorous vacuole The microgamont measured 18×10 μm and was covered by a single membrane, having micropores and some underlying osmiophilic material On day 3 pi its nucleus was divided and four uni-flagellated microgametes developed The pear-like microgamete measured 6 μm in length and mainly contained the nucleus; in a groove of the nucleus the mitochondrion and 6–8 microtubules were observed The single flagellum measured 23 μm in length and had only single microtubules in an 8+2 or 9+1 arrangement The macrogamont measured 25–35 μm, contained accumulations of mitochondria, endoplasmic reticulum (rough, smooth) and several Golgi apparatus It was covered by two membranes with micropores, but the inner membrane showed some interruptions at many places The cytoplasm of the oocyst divided into about 52 (15–75) sporoblasts on day 10 pi Inside sporoblasts, cristalloidal bodies were associated Sporocysts first were seen on day 13 pi They had a two-layered thickened wall On day 16 pi about 26 sporozoites of 9×2 μm developed inside each sporocyst The sporozoites ofH aegypti had the characteristic fine structure of the merozoites and stages in the red blood cells studied in the snakeSpalerosophis diadema; in addition they had two large crystalloid bodies on both sides of the nucleus
35 citations
01 Dec 1984-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this paper, the mass transfer coefficient characterizing the rate of dissolution of immersed carbon rods depends both on the absolute values of the melt velocity and on the local values of turbulence intensity; thus significant mass transfer will occur in the region of the eye of the circulation, where the absolute value of the mean velocity is small.
Abstract: Experimental measurements are reported on melt velocities and on the rate at which immersed carbon rods dissolve in a 4-ton induction furnace, holding a low carbon steel melt. These measurements are compared with theoretical predictions, based on the numerical solution of Maxwell’s equations and the turbulent Navier-Stokes equations. In general, good agreement has been obtained, both regarding the absolute values of the velocities and the mass transfer coefficients and the trends predicted by the theoretical analysis. In addition to providing further proof regarding the applicability of the mathematical modeling technique, the principal contribution of the work is that it provides an improved insight into the behavior of inductively stirred melts. In particular it was found that for an inductively stirred melt both the velocities and the rate of turbulence energy dissipation are relatively uniform spatially, in contrast to bubble stirred systems, where most of the agitation is confined to the jet plume and to the near surface region. It was found, furthermore, that the mass transfer coefficient characterizing the rate of dissolution of immersed carbon rods depends both on the absolute values of the melt velocity and on the local values of the turbulence intensity; thus significant mass transfer will occur in the region of the eye of the circulation, where the absolute value of the mean velocity is small.
32 citations
TL;DR: The electrode time lag was found to be independent of both the system studied and the operating conditions, and the volumetric oxygen mass transfer coefficients kLa could be reasonably predicted by calculating kL from the equation derived by Bhavaraju et al.
Abstract: Liquid-phase volumetric oxygen transfer coefficients were evaluated in a bubble column containing yeast suspensions, using the instationary oxygen absorption method and a polarographic oxygen electrode. The electrode time lag was found to be independent of both the system studied and the operating conditions. The volumetric oxygen mass transfer coefficients k
L
a could be reasonably predicted by calculating k
L from the equation derived by Bhavaraju et al. or the empirical equation of Calderbank and Moo-Young and “a” from the experimental gas hold-up values.
32 citations
TL;DR: The present study suggests that immunological defects attributed to reptiles might be more apparent than real, and essentially ascribable to the fact that the immune capacity of these ectothermic vertebrates is profoundly modulated by environmental conditions.
TL;DR: A new technique of cystography used in 32 patients with a normal anorectum is presented, and in no film up to two hours did the dye appear in the pyelocalyceal system or the ureters.
TL;DR: In this article, the authors formulated an optimization problem with a view to maximizing the load-carrying capacity of a multi-recess HJ bearing with the objective of maximizing the flow rate and power ration.
TL;DR: An anomalously short mean free path of 10.93 cm was found for secondary $Z=2$ fragments of $4.5$ cm from their production in nuclear emulsions as mentioned in this paper.
Abstract: An anomalously short mean free path of 10.93 \ifmmode\pm\else\textpm\fi{} 2.00 cm is found for secondary $Z=2$ fragments of $4.5A$-GeV/c $^{12}\mathrm{C}$ projectiles at distances $Dl~2.5$ cm from their production in nuclear emulsions. The largest contribution to this anomalous short---mean-free-path component comes from ${N}_{h}=0$ interactions of $^{12}\mathrm{C}$ in emulsion.
TL;DR: A journal bearing test rig was designed and constructed to test the behavior of journals with wavy surfaces, the circumferential undulations being varied both in amplitude and in number as discussed by the authors.
TL;DR: The most common finding in the whole series was that of normal testis denoting obstruction, while among cases of functional azoospermia, Sertoli cell only and spermatogenic arrest were the most frequent.
Abstract: The continued experience of testicular biopsy application in 861 cases of azoospermia and 152 cases of severe oligospermia is reported adding to the previously published cases of 1075 patients with azoospermia. The most common finding in the whole series was that of normal testis denoting obstruction (48%), while among cases of functional azoospermia, Sertoli cell only and spermatogenic arrest were the most frequent (66%).
TL;DR: In this paper, the reaction of 2-cyanoethanoic acid hydrazide and arylidenemalononitrile was studied as a new route for the synthesis of N-amino-2-pyridones.
TL;DR: In this paper, 5.5-Amino-3-phenylpyrazole (I) and 5-amino-4-bromo-, 3.3-pylpyridines (II) reacted with ethyl acetoacetate and acetylacetone to give various pyrazolo[1,5-a]pyrimidines IV-VI and with benzoins to give different fused pyrazoles, namely, imidazo [1,2-b]pyrazoles IX, pyrrolo[
TL;DR: The essential oil of Artemisia monosperma obtained by steam distillation of the aerial parts of the plant was shown to have insecticidal activity against house fly, cotton leaf worm and the rice weevil as discussed by the authors.
TL;DR: The findings suggested that HC-mediated lymphocyte depletion in lizards is not attributable to redistribution between the different lymphoid compartments but rather to destruction.
Abstract: A single dose of 1 mg/g body weight of hydrocortisone acetate (HC) administered intraperitoneally to adult lizards, Chalcides ocellatus induced rapidly a reduction of about 85% of thymic lymphocytes. Histological evidence indicated that cortical, as well as, medullary thymocytes are sensitive to HC exposure. Around 40-50% of lymphocytes in peripheral blood (PB) and spleen were depleted at 3-7 days post-HC injection; such depletion durated about 4 weeks for PB but was rather temporary in spleen. Increase in number of bone marrow (BM) lymphocytes was negligible and transient and could by no way account for the dramatic cell losses in the different lymphoid tissues. The findings thus suggested that HC-mediated lymphocyte depletion in lizards is not attributable to redistribution between the different lymphoid compartments but rather to destruction. In direct conformation, lymphocytes were readily lysed in vitro by 10(-3)M HC, thymocytes being more vulnerable greater than PB greater than spleen greater than BM lymphocytes.
TL;DR: Bayesian inferential and forecasting techniques which can be used with any moving average process are developed by employing the conditional likelihood function, at-approximation to the predictive distribution and the marginal posterior distribution of the moving average parameters.
Abstract: This paper will develop Bayesian inferential and forecasting techniques which can be used with any moving average process. By employing the conditional likelihood function, at-approximation to the predictive distribution and the marginal posterior distribution of the moving average parameters is developed. Several examples demonstrate posterior and predictive inferences.
TL;DR: In this paper, the pyrazolo[1,5-a]-s-triazine derivative was cyclised to 2-benzoylamino-5-cyanomethyl-1,3,4-thiadiazole (8) when boiled under reflux in glacial acetic acid.
01 Jan 1984-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
Journal Article•
TL;DR: Results indicated that HC induced stepwise, time-dependent mortality of the majority of thymocytes carrying T cell specific antigen(s) (TSA), 30-50% of T cells of spleen, PB and BM, and of a proportion of splenic B lymphocytes.
Abstract: Lymphocytes of thymus, spleen, peripheral blood (PB) and bone marrow (BM) collected from adult lizards, Chalcides ocellatus were cultured for 24 hr in the presence of 10−3M hydrocortisone acetate (HC) in order to assess the effect of in vitro HC on lizard T and B cell viability. The results indicated that HC induced stepwise, time-dependent mortality of the majority of thymocytes carrying T cell specific antigen(s) (TSA), 30–50% of T cells of spleen, PB and BM, and of a proportion of splenic B lymphocytes. Administration of 1 mg/g body weight HC to adult Ch . ocellatus lead to depletion of all TSA+ thymocytes. In contrast, T lymphocytes in the peripheral lymphoid compartments revealed both sensitivity and resistance to HC; similarly, B lymphocytes constituted susceptible and resistant subpopulations.
TL;DR: In this paper, the 4-Amino-3-(methylthio)-6-R-1,2,4-triazin-5(4H)-one 6-10 ergaben bei der Umsetzung mit Anthranilsaure die 1-A Amino-2-R 2H-as-Triazino[3,2-b]chinazolin-2,6(1H)-dione 17-21 anstelle der erwarteten as-TriZino[ 3,4b
Abstract: 4-Amino-3-(methylthio)-6-R-1,2,4-triazin-5(4H)-ones 6 – 10 react with anthranilic acid to yield the 1-amino-3-R-2H-as-triazino[3,2-b]quinazoline-2,6(1H)-diones 17 – 21 rather than the expected as-triazino[3,4-b][1,3,4]benzotriazepines 12 – 16. Compounds 17 – 21 were deaminated into compounds 22 – 26. Heating of the N-benzylidene derivatives of 6 – 10 (27 – 31) with anthranilic acid also led to the formation of 22 – 26 with extrusion of benzonitrile.
Synthese und Struktur von as-Triazinochinazolinen, II1)
Die 4-Amino-3-(methylthio)-6-R-1,2,4-triazin-5(4H)-one 6 – 10 ergaben bei der Umsetzung mit Anthranilsaure die 1-Amino-3-R-2H-as-triazino[3,2-b]chinazolin-2,6(1H)-dione 17 – 21 anstelle der erwarteten as-Triazino[3,4-b][1,3,4]benzotriazepine 12 – 16. Die Verbindungen 17 – 21 liesen sich zu 22 – 26 desaminieren. Erhitzen der N-Benzylidenderivate von 6 – 10 (27 – 31) mit Anthranilsaure fuhrte unter Freisetzung von Benzonitril ebenfalls zu 22 – 26.
TL;DR: No essential changes were observed after ligation of the blood vessels, except in one case where collateral circulation was established, and neurectomy by the technique of Fackelman and Clodius proved superior to the traditional method.
Abstract: Summary
Clinical and pathological changes following neurectomy were studied experimentally in 46 male and female equids. Sixty-three operations were performed using either the traditional or the Fackelman and Clodius methods of neurectomy. The effect of arteriovenous ligation was studied in 12 animals and 20 angiograms were performed post mortem to study the arterial pattern of the extremities of the operated limb. Neuroma formation (31 cases) and sloughing of the hoof (five cases) were the two main untoward sequelae. Neurectomy by the technique of Fackelman and Clodius proved superior to the traditional method. No essential changes were observed after ligation of the blood vessels, except in one case where collateral circulation was established.
TL;DR: In this article, a simple one-dimensional model was proposed for pure H2O- and CO2-ices in a very simple one dimensional model assuming uniform thermal conductivity and temperature gradient.
Abstract: Pores present in ices in the solar system do not remain unchanged. In isothermal conditions they shrink, while in a thermal gradient they migrate towards the higher temperature and escape so that the ice densifies. This motion has been investigated for pure H2O- and CO2-ices in a very simple one-dimensional model assuming uniform thermal conductivity and temperature gradient. The results indicate that the densification of H2O-ice is so slow that it could be significant only for icy satellites having an internal heat source. On the other hand, CO2-ice densifies orders of magnitude faster and the effect should be important for the CO2 component of cometary nuclei. No effect is expected for icy planetary rings.
TL;DR: A nuclear polyhedrosis virus was evaluated in the field against Spodoptera littoralis larvae on cotton in Egypt and showed that a suspension of the virus in water with molasses, a wetting agent and an ultra‐violet absorber was as effective in reducing damage as collecting the egg masses or applying chemical insecticides.
Abstract: A nuclear polyhedrosis virus was evaluated in the field against Spodoptera littoralis (Boisd.) larvae on cotton in Egypt. Small plot trials demonstrated that damage in plots sprayed with virus was less than in an untreated control plot. Larger scale trials in light to moderately infested plots showed that a suspension of the virus in water with molasses, a wetting agent and an ultra‐violet absorber, applied with a knapsack sprayer with cotton tailboom, was as effective in reducing damage as collecting the egg masses or applying chemical insecticides.
TL;DR: In this article, the role of Fe in Calcium Silicate glasses was investigated using conductivity, Mossbauer Spectroscopy and Electron Spin Resonance (ESR) techniques.