Showing papers by "Bar-Ilan University published in 1976"
TL;DR: Algorithms to generate the n-bit binary reflected Gray code and codewords of fixed weight in that code are presented and applications to the generation of the combinations of n things taken k at a time, the compositions of integers, and the permutations of a multiset are discussed.
Abstract: Algorithms are presented to generate the n-bit binary reflected Gray code and codewords of fixed weight in that code. Both algorithms are efficient in that the time required to generate the next element from the current one is constant. Applications to the generation of the combinations of n things taken k at a time, the compositions of integers, and the permutations of a multiset are discussed.
292 citations
TL;DR: The results suggest that electrical stimulation decreases the AChR level by decreasing the synthesis of the receptors rather than by degrading or inactivating them.
Abstract: MUSCLE activity has been shown to be a central factor in controlling the level of extrajunctional acetylcholine receptors (AChR): inactivity of muscle fibres causes an increase in the number of AChR and electrically stimulated activity causes a decrease. We investigated the mechanism by which this activity regulates the level of AChR in muscle fibres that have differentiated in cell culture. Our results suggest that electrical stimulation decreases the AChR level by decreasing the synthesis of the receptors rather than by degrading or inactivating them.
83 citations
TL;DR: In this paper, a scanning radiomctcr was used for in situ determinations of the light utilization efficicncics of phytoplankton in Lake Kinneret.
Abstract: Abstmct A scanning radiomctcr was used for in situ determinations of the light utilization efficicncics of phytoplankton in Lake Kinneret. For a profile measured during the near maximum of daily irradiance in July, light utilization efficiencies in the epilimnion ranged from 0.07-2.61%, increasing with depth down to the thcrmoclinc where maximum quantum efficiencies of 0.07 molts C cinstcin-1 absorbed wcrc cstimatcd. Light utilization efficiency integrated for the cpilimnctic water column was 0.35%.
77 citations
68 citations
TL;DR: “Induction” of receptors by tetrodotoxin was inhibited by cycloheximide, actinomycin-D, or 5-bromotubercidine, and dystrophic muscle responded in vitro to inhibition of contraction similar to normal tissue.
Abstract: Acetylcholine receptors in muscle cells differentiated in vitro were monitored by using125I-α-bungarotoxin. The number of cholinergic receptors was increased 4–8 fold in 2 days due to inhibition of spontaneous contraction of the muscle fibers. The inhibition of this activity, whether mediated through tetrodotoxin, lidocaine or D-600, did not affect the biochemical differentiation of muscle, as represented by creatine-phosphokinase and acetylcholinesterase activity. “Induction” of receptors by tetrodotoxin was inhibited by cycloheximide, actinomycin-D, or 5-bromotubercidine. Dystrophic muscle responded in vitro to inhibition of contraction similar to normal tissue.
66 citations
TL;DR: The metabolic state of an awake cerebral cortex was identified by exposing the brain to various levels of oxygen, epileptoform activity, spreading depression, hyperbaric pressure of oxygen and an uncoupler, and it is concluded that the awake cortex is close to the resting state, state 4, rather than to the active state, states 3.
64 citations
TL;DR: A procedure has now been developed for inducing clonal proliferation of mitogen-stimulated mouse lymphocytes using a two-layer soft agar technique for clonal growth of human lymphocyte colonies in vitro.
Abstract: TECHNIQUES have been developed for the growth of haemopoietic cells (see refs 1 and 2), human T lymphocytes3 and mouse B lymphocytes4 on soft agar. Experiments with mouse lymphocytes suggest that concanavalin A (con A) and phytohaemagglutinin (PHA) stimulate T cells5,6, whereas pokeweed induces proliferation of both B and T cells7. Based on previously described techniques for obtaining clonal growth of human lymphocyte colonies in vitro3, a procedure has now been developed for inducing clonal proliferation of mitogen-stimulated mouse lymphocytes using a two-layer soft agar technique.
62 citations
TL;DR: The data indicate partial integration, with approximately a 6 dB decrease in threshold per decade increase in noise burst duration for both conditions of stimulation for durations ranging from 4 to 256 msec.
Abstract: A comparison was made between monaural and binaural temporal integration of noise bursts at threshold. The data indicate partial integration, with approximately a 6 dB decrease in threshold per decade increase in noise burst duration for both conditions of stimulation (i.e., parallel functions) for durations ranging from 4 to 256 msec. When thresholds in dB are plotted as a function of log duration, the linear component accounts for 99% of the data indicating no essential change in the partial integration functions up to at least 256 msec. The intercept difference between the monaural and binaural integration functions is 2.5 dB.
54 citations
TL;DR: Ather (I) erhalt man mit Dibromcarben (II) das Bis-Addukt (III), das mit Methyllithium zum Diallenyl-Derivat (V) und weiter zum Furan (VI) reagiert.
54 citations
TL;DR: The results suggest that CSF may play a physiologic role in vivo as a granulopoietin and it was shown that the genetic control mechanisms governing the CSF/CFC responses are determined by the lipid A‐KDO portion of the LPS molecule, suggesting that lipid A is the active part of theLPS molecule in stimulating granulipoiesis.
Abstract: Administration of bacterial lipopolysaccharides (LPS) to mice causes a rise in tissue and serum colony stimulating factor (CSF) levels and in bone marrow and splenic colony forming cells (CFC). Two inbred strains of mice differing in their response to LPS were used to study the genetic control of LPS induced granulopoietic responses: a high responder strain (C3H/eB) which reacts to LPS by an elevation in serum CSF and by an increase in splenic CFC levels, and a low responder strain (C3H/HeJ) which fails to show these responses. The ability to generate serum CSF after administration of LPS is controlled by a single autosomal dominant gene, while the splenic CFC response to LPS follows the characteristic patterns of a polygenic inheritance control. The associated relationships of CSF and CFC responsiveness have been investigated in backcross (F1 x C3H/HeJ) and F2 mice. Most mice which generated high levels of CSF showed a high or intermediate CFC response and most mice which did not generate any detectable levels of serum CSF showed a low splenic CFC response. The results suggest that CSF may play a physiologic role in vivo as a granulopoietin. In addition it was shown that the genetic control mechanisms governing the CSF/CFC responses are determined by the lipid A-KDO portion of the LPS molecule, suggesting that lipid A is the active part of the LPS molecule in stimulating granulopoiesis.
52 citations
TL;DR: The fact that even the most defective LPS from the R mutant R595 which contains lipid A and KDO only is a potent endotoxin, points unequivocally, to lipid A, as the active principle in stimulating the granulopoietic system.
Abstract: An analysis of which component of lipopolysaccharides (LPS), the lipid or the polysaccharide (PS), is active in stimulating the murine granulopoietic system has been performed. LPS with different structures, isolated from different mutant strains of Salmonella and chemical degradation products of lipopolysaccharides have been used. Lipid A obtained by acid hydrolysys of the LPS and complexed to bovine serum albumin (BSA) (lipid A-BSA) was shown to be active in generating serum colony stimulating factor (CSF) and in increasing the splenic colony forming cells (CFC) levels, although it was less active than the parent LPS. The polysaccharide (PS) showed no significant activity at the concentrations used. LPS (glycolipids) from R mutants of Salmonella minnesota were active to the same extent as the LPS. The fact that even the most defective LPS from the R mutant R595 which contains lipid A and KDO only is a potent endotoxin, points unequivocally, to lipid A, as the active principle in stimulating the granulopoietic system.
TL;DR: In this paper, a set of dipole impurities are randomly distributed in a nonpolar medium where the only interaction between the impurities is the dipole-dipole interaction.
Abstract: We consider a set of dipole impurities randomly distributed in a nonpolar medium where the only interaction between the impurities is the dipole-dipole interaction. The dipoles are assumed to be oriented in the six equivalent (1,0,0) directions found experimentally to exist when O${\mathrm{H}}^{\ensuremath{-}}$ impurities are dissolved in KC1 crystals. Effects arising from tunneling between the six equivalent directions are neglected. We set up the expression for the random molecular electric field vector $\stackrel{\ensuremath{\rightarrow}}{E}$ at a particular impurity site and derive self-consistently the probability distribution of $\stackrel{\ensuremath{\rightarrow}}{E}$ for all temperatures and (sufficiently low) impurity concentrations. The thermodynamic properties of the system are then obtained by integrating the thermodynamic variable of a single dipole in a fixed vector field $\stackrel{\ensuremath{\rightarrow}}{E}$ over the distribution of all fields. Evaluating the thermodynamic properties arising from the dipole-dipole interaction we show that the dielectric susceptibility scales with the ratio of the temperature $T$ to the impurity concentation $c$. Similarly the specific heat per impurity scales with $\frac{T}{c}$. Even though the experimentally measured ${T}^{\frac{3}{2}}{c}^{\ensuremath{-}\frac{1}{2}}$ dependence of the specific heat is consistent with our "scaling" requirements, indicating that the dipole-dipole interaction is involved in the excess low-temperature specific heat, our theory gives that the specific heat is linear in $T$ and independent of $c$ for very low temperatures. Thus, the dipole-dipole interaction alone, using a molecular-field approximation, does not explain the experimentally observed low-$T$ specific heat. A detailed study of the temperature dependence, the concentration dependence, and the scaling properties of the specific heat and the dielectric susceptibility are discussed and compared with experiment.
TL;DR: The 1939 White Paper remained the basis of British rule in Palestine during the first three years of war as mentioned in this paper and the military crises that erupted in the Middle East between 1940 and 1942 did not permit consideration of any alternatives - if only because Britain could not be certain that in would still be in the area at the end of the war.
Abstract: The 1939 White Paper remained the basis of British rule in Palestine during the first three years of war. The military crises that erupted in the Middle East between 1940 and 1942 did not permit consideration of any alternatives - if only because Britain could not be certain that in would still be in the area at the end of the war. Since his appointment to the War Cabinet in September 1939, Churchill had tried, in vain, to halt the implementation of the White Paper.
TL;DR: Mature weight of both basal and upper caryopses was higher when produced on plants grown at low temperature, or transferred from 16-h to 8-h photoperiods at emergence of the flag leaf.
Abstract: Aegilops Kotschyi Boiss. plants produce three florets per spikelet (of which the terminal floret is commonly sterile) and exhibit physiological heterocarpy in the two caryopses which develop in each spikelet. Germinability of the basal caryopsis, but not of the upper one, was subject to environmental influences to which the parent plant was exposed during its development. Basal caryopses produced by plants grown at low temperature, or in 16-h photoperiods, were more dormant than when produced by plants grown at higher temperature, or in 8-h photo periods. Germinability of the upper caryopses was equally high in all cases and independent of the parental environment. The photoperiod effects on germinability were exerted after anthesis. Mature weight of both basal and upper caryopses was higher when produced on plants grown at low temperature, or transferred from 16-h to 8-h photoperiods at emergence of the flag leaf.
TL;DR: The stock of T. nilotica, T. vulcani and T. aurea analysed, by polyacrylamide gel electrophoresis, for the existence of species-specific markers found to be male sex and species specific, it was concluded that these species do not represent the pure species.
TL;DR: Evaluation of the significance of the formation by hairy cells of mouse erythrocyte rosettes, as well as the presence of the typical hair-like projections, may require additional knowledge concerning the membrane of these cells.
Abstract: Studies of peripheral blood, bone marrow, and spleen cells from three patients with hairy-cell leukemia were performed. Two of the three patients had well-organized cytoplasmic, ribosome-lamellar inclusions in their leukemic cells. Blast transformation and 3H-thymidine incorporation of lymphocytes seemed to fall within normal ranges when the findings were related to the absolute numbers of lymphocytes. The enzymatic markers demonstrated in hairy cells-strong acid phosphatase activity in endoplasmic reticulum and lysosomes, marked alpha-naphthyl acetate esterase reaction, and weak beta-glucuronidase activity-as well as their phagocytosis of latex particles, indicate a common origin with monocytes or histiocytes. No decisive results were obtained by immunofluorescence. Evaluation of the significance of the formation by hairy cells of mouse erythrocyte rosettes, as well as the presence of the typical hair-like projections, may require additional knowledge concerning the membrane of these cells.
TL;DR: In this article, a combination of multi-configuration self-consistent field theory and configuration mixing techniques was used to identify the first satellite states of planar formamide using X-ray and ultraviolet photoelectron spectra.
TL;DR: In this paper, the transverse dielectric constant of K${\mathrm{D}}_{2}$P${O}}_{4}$ was measured in the temperature range $79lTl322$ \ifmmode^\circ\else\textdegree\fi{}K.
Abstract: The transverse dielectric constant of K${\mathrm{D}}_{2}$P${\mathrm{O}}_{4}$ was measured in the temperature range $79lTl322$ \ifmmode^\circ\else\textdegree\fi{}K. A large discontinuity appears at the transition temperature ${T}_{c}$ indicating a well-defined first-order transition. A new feature of the data is a dome-shaped figure above ${T}_{c}$, resembling the magnetic susceptibility of many antiferromagnetic materials. Extension of a well-known pseudospin model for K${\mathrm{H}}_{2}$P${\mathrm{O}}_{4}$ to the transverse direction is achieved by taking into account the direct contribution of the displacements of the protons to the transverse polarization. Calculation of the transverse susceptibility for this model within the four-cluster approximation leads to a new independent determination of the Slater-Takagi energy configuration parameters ${\ensuremath{\epsilon}}_{0}$ and $\ensuremath{\epsilon}$. Excellent fit to the data is achieved for the choices $\frac{{\ensuremath{\epsilon}}_{0}}{{k}_{B}}=92$ \ifmmode^\circ\else\textdegree\fi{}K, $\frac{{\ensuremath{\epsilon}}_{1}}{{k}_{B}}=907$ \ifmmode^\circ\else\textdegree\fi{}K and indicates that the tunneling integral for K${\mathrm{D}}_{2}$P${\mathrm{O}}_{4}$ is negligible. These values are very close to those derived by independent measurements of ultrasonic sould velocity and specific heat. The results of the model are also compared with the available data for the transverse susceptibility of Cs${\mathrm{H}}_{2}$As${\mathrm{O}}_{4}$.
TL;DR: This article found that the moderate guilt-arousing leaflet was more effective than the low and high guiltarousing leaflets in motivating the students to volunteer for the civil guard, which was interpreted as supporting Janis's model, which predicted a curvilinear relationship between the intensity of guilt and the amount of change in attitude or behavior.
Abstract: Three intensities of guilt about not volunteering to the civil guard were aroused by distributing appropriate leaflets among three groups (30 students per group) of 12th graders. A fourth group of 30 12th graders served as a control and did not receive any leaflet. All four groups could choose to devote different amounts of their time for serving in the civil guard or to refuse to volunteer at all. It was found that the moderate guilt-arousing leaflet was more effective than the low and high guilt-arousing leaflets in motivating the students to volunteer for the civil guard. The results were interpreted as supporting Janis’s model, which predicted a curvilinear relationship between the intensity of guilt and the amount of change in attitude or behavior.
TL;DR: Differences in pigmentation of the caryopses follow a corresponding pattern, inasmuch as the uppermost developing caryopsis is least dormant and its development is associated with the dormancy status imposed on the lower (one or two) caryopsy.
Abstract: Caryopses of Aegilops kotschyi Boiss. from different positions within the same spikelet differ greatly in their degree of dormancy. Imposition of this dormancy pattern is a correlative phenomenon within the spikelet, inasmuch as the uppermost developing caryopsis is least dormant and its development is associated with the dormancy status imposed on the lower (one or two) caryopses. Differences in pigmentation of the caryopses follow a corresponding pattern.
TL;DR: In the present study iodoacetic acid has been used to probe the active site of lipoxygenase, which is not a substrate analog; nevertheless it inhibits this enzyme by binding specifically to a methionine residue at or near theactive site.
TL;DR: It seems that neither type of lesion affected dopaminergic neuronal activity in the brain, however, norepinephrine activity inThe brain was affected by the area postrema lesion as well as by the olfactory bulb removal.
Abstract: Lesions in either olfactory bulb or in area postrema modify the amphetamine-induced paradoxical thermoregulatory behavior, although these lesions in no way affect amphetamine-induced hypothermia. In addition, these lesions lead to complicated patterns of thermoregulatory behavior. These results can be best explained by assuming that lesions in one part of the brain monoamine system might affect levels and turnover of monoamines in remote parts of the brain. Among d-amphetamine behavioral effects which are known to be mediated by central dopaminergic neurons are hypothermia in animals placed in a cold environment, and paradoxical thermoregulatory behavior (this involves the movement of animals away from the heating source despite hypothermia). This latter effect requires intact alpha norepi- nephrine receptors. It seems that neither type of lesion affected dopaminergic neuronal activity in the brain. However, norepinephrine activity in the brain was affected by the area postrema lesion as well as by the olfactory bulb removal.
TL;DR: In this article, the authors used Partial Order Scalogram Analysis (POSA) to find four sources of worries experienced by the employees of accounting departments: job security, job stability, job proficiency, and job interest.
Abstract: The introduction of a major change in an organization, like computerization, may be expected to raise some worries on the part of affected employees. Four sources of worries experienced by the employees of accounting departments are discussed: job security, job stability, job proficiency, and job interest. An empirical structure of these worries, based on scalogram technique, was found, and an interpretation for it is proposed. By the use of Partial Order Scalogram Analysis, a parsimonious description of the contents behind the variables was obtained. Empirical profiles can be characterized by two scores, rather than the original four, by means of two scales: the joint scale represents the "amount" of worry and the lateral scale measures the composition or the "quality" of worry. The findings confirm our hypothesis concerning the content underlying the lateral ("quality-of-worries') scale, namely that it reflects the degree of "intrinsicality" versus "extrinsicality" of the job reward the loss of which is...
TL;DR: Findings show that considerable changes in pigment composition in natural phytoplankton can occur while the species composition remains constant.
Abstract: Pigment analyses by TLC were carried out during and after the peak of a Peridinium bloom in Lake Kinneret (Israel). During the experimental period considerable changes occurred in the absolute and relative amounts of the various pigments, especially β carotene, diadinoxanthine, peridinin, chlorophyll a and chlorophyl c. The ratio between total Carotenoid to total chlorophyll content is also followed. Our findings show that considerable changes in pigment composition in natural phytoplankton can occur while the species composition remains constant.
TL;DR: The freezing procedure avoids most of the postmortem changes of brain metabolites levels, but the events of the first few seconds after decapitation are obscure.
Abstract: The effects of complete ischemia on brain energy metabolism have been studied in various animal preparation (1,2,3,4). One of the approaches on studying those effects is to convert the brain into a closed system, by decapitation, and after fixation of the tissue to measure changes in various metabolites such as glucose, lactate, ATP and creatine phosphate. The freezing procedure avoids most of the postmortem changes of brain metabolites levels, but the events of the first few seconds after decapitation are obscure.
TL;DR: The isolated fraction contained about 0.3% of the total sperm DNA, showed a fivefold enrichment in cytochrome oxidase and succinate dehydrogenase activities, and twofold enrichment of NADH dehydrogenases activity.
TL;DR: A comparison was made of electrocutaneous magnitude estimation data across two experiments with contextual differences not involving stimulus parameters, such as number and range of stimuli and relative position of the standard in the stimulus range.
Abstract: A comparison was made of electrocutaneous magnitude estimation data across two experiments with contextual differences not involving stimulus parameters, such as number and range of stimuli and relative position of the standard in the stimulus range. The data were fitted by 2-parameter linear, log-linear and power functions. When the data are fitted by either linear or log-linear equations, both intercept and slope parameters are significantly affected by the different contextual factors. When the data are fitted by a power function, however, only the intercept is altered; the slope remains invariant despite contextual changes introduced in the second experiment.
TL;DR: In this paper, the role of cyclicity in perceptual-cognitive functioning was studied for human-figure drawings and embedded-figures in the third week of the cycle for 155 college women and for 116 girls and unmarried women.
Abstract: Better performance on human-figure drawings and embedded-figures was found for the third week of the cycle for 155 college women and for a second group of 116 girls and unmarried women. Further study of the role of cyclicity in perceptual-cognitive functioning is desirable.
TL;DR: An antigen found only in Tc-resistant strains was produced by adsorbing envelope extracts from these strains with immunoglobulin against envelopes from isogenic TC-susceptible strains, and behaved as proteins.
Abstract: Immunoglobulin (adsorbed resistance antiserum) reacting specifically with antigens from tetracycline (Tc)-resistant Staphylcoccus aureus or Escherichia coli was produced by adsorbing immunoglobulin against cell envelopes of resistant strains with envelope extracts from the respective isogenic susceptible strains. Adsorbed resistance antiserum against S. aureus reacted with envelope extracts from 32 Tc-resistant strains and failed to react with similar extracts from 76 Tc-susceptible strains of S. aureus . An antigen (Tc resistance antigen [TRA]) found only in Tc-resistant strains was produced by adsorbing envelope extracts from these strains with immunoglobulin against envelopes from isogenic Tc-susceptible strains. On immunodiffusion no cross-reactivity between TRAs from S. aureus and E. coli was observed. The TRAs behaved as proteins. The molecular weight of TRA from S. aureus was determined to be 32,000 and from E. coli to be 50,000. Data obtained by preliminary amino acid analysis of the TRAs are presented. Images