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Showing papers by "Ben-Gurion University of the Negev published in 1992"


Journal ArticleDOI
TL;DR: In this article, simultaneous measurements of the reflectance spectra in the region of 400 to 750 nm and relevant water quality constituent concentrations (chlorophyll, dissolved organic matter and suspended matter) were carried out.
Abstract: To investigate the nature of the peak near 700 nm on reflectance spectrum of water, simultaneous measurements of the reflectance spectra in the region of 400 to 750 nm and relevant water quality constituent concentrations (chlorophyll, dissolved organic matter and suspended matter) were carried out. The data set cover various trophic states of water bodies, all seasons and different climatic regimes. A shift of the peak position from about 680 nm up to 7l5 nm and an increase of the peak magnitude when chlorophyll concentration increased were observed. The magnitude and the peak position could be used as precise indicators and predictors for the phytoplankton concentration. It contributed significantly to the increase in the accuracy of the derivation of chlorophyll values from multispectral data.

602 citations


Journal ArticleDOI
TL;DR: This paper found that subjects reacted more strongly to adverse outcomes caused by action, whether the status quo was maintained or not, and subjects preferred inaction over action even when inaction was associated with change.
Abstract: Bias toward the status quo, found in choice and in emotional reactions to adverse outcomes, has been confounded with bias toward omission. We unconfounded these effects with scenarios in which change occurs unless action is taken. Subjects reacted more strongly to adverse outcomes caused by action, whether the status quo was maintained or not, and subjects preferred inaction over action even when inaction was associated with change. No status-quo bias was found in a matching task, which did not require action. The observed status-quo bias is at least partly caused by a bias toward omissions.

533 citations


Journal ArticleDOI
TL;DR: The results suggest that the Stroop effect is controllable (see Logan, 1980) and that the locus of control is postlexical and suggest that facilitation and inhibition are produced by different mechanisms.
Abstract: An important characteristic of automatic processing is its uncontrollability. The Stroop phenomenon is regarded as a prototypical example of this characteristic of automatic processing, hence, the Stroop effect should not change when the percentages of color words versus neutral stimuli are manipulated to induce controlled processing. We found that Stroop interference decreased as the percentage of color words increased. Furthermore, the magnitude of the inhibitory component of the Stroop effect was negatively correlated with the percentage of color words; the facilitatory component was insensitive to the manipulation. These results suggest that the Stroop effect is controllable (see Logan, 1980) and that the locus of control is postlexical. The results also suggest that facilitation and inhibition are produced by different mechanisms and challenge those models of the Stroop phenomenon (e.g., Cohen, Dunbar, & McClelland, 1990; Phaf, Van der Heijden, & Hudson, 1990) that assume that a single processing mechanism causes facilitation and inhibition and that control affects facilitation and inhibition alike (Logan, 1980).

286 citations


Journal ArticleDOI
TL;DR: The paper proposes that Antonovsky's salutogenic orientation and his sense of coherence (SOC) concept provide a sound theoretical basis for the study and strengthening of the caring component in clinical practice and consistently supported the view that the SOC scale is a robust instrument.
Abstract: . The paper proposes that Antonovsky's salutogenic orientation and his sense of coherence (SOC) concept provide a sound theoretical basis for the study and strengthening of the caring component in clinical practice. In order to study the operational utility of the concept, the 29-item SOC questionnaire (in two formats) was administered to five Swedish samples (3 groups of nurses, patients in a hospital emergency department, and a general population sample). Psychometric data are provided which test the internal and test-retest reliability of the SOC scale. A Self-Motivation Inventory (SMI) and the Karolinska Scales of Personality (KSP) were used to test the relation between the SOC concept and personality traits. The results revealed that those with strong SOC also scored as having more general motivation and less Somatic and Psychic Anxiety as well as less Hostility. In addition the data, though in some part modest in sample size, consistently supported the view that the SOC scale is a robust instrument. Particular note is taken of its crosscultural character and of its potential utility in clinical work.

280 citations


Journal Article
TL;DR: Gerbillus allenbyi and G. pyramidum showed a significant light x snake x owl interaction indicative of predator facilitation: the gerbils avoided the open entirely when faced with lights and owls, but increased their exposure to owls if vipers were also present.
Abstract: Predator facilitation occurs when prey face two or more predator species and cannot forage and be safe from both types of predators simultaneously: avoiding one predator necessarily leads to increased exposure to the other Two species of coexisting gerbils 0Gerbillus allenbyi and G pyramidum) which coexist in sandy habitats in the Negev Desert, Israel may face such conflicting demands from vipers and owls We tested this by subjecting the gerbils to the presence of snakes and owls in a factorial experiment carried out in a large aviary We also manipulated illumination and microhabitat, two factors which affect the risk of predation Gerbils responded to owls by reducing foraging activity, avoiding the open microhabitat, and exploiting resource patches less intensively Also, G pyramidum showed a significant light x snake x owl interaction indicative of predator facilitation: the gerbils avoided the open entirely when faced with lights and owls, but increased their exposure to owls if vipers were also present The fangs of the snakes are driving the gerbils into the talons of the owls Such facilitation may affect the foraging behavior, species interactions, and community structure of the gerbils

207 citations


Journal ArticleDOI
TL;DR: Five cases of the Pentalogy of Cantrell, ascertained through the Baltimore-Washington population-based study of infants with congenital cardiovascular malformations, represent a regional prevalence of 5.5/1 million liveborn infants for this disorder.
Abstract: Five cases of the Pentalogy of Cantrell (PC), ascertained through the Baltimore–Washington population-based study of infants with congenital cardiovascular malformations, represent a regional prevalence of 5.5/1 million liveborn infants for this disorder. Three of these patients had cleft lip with or without palate. Review of the reported literature of the Pentalogy of Cantrell and various combinations of the anomalies within the spectrum of this pentad suggests that the PC defines a specific midline ventral developmental field. Cleft lip with or without cleft palate and encephalocele tend to specifically associate with ventral midline anomalies within the spectrum of PC. These associations might either illustrate the previously observed tendency of specific occurrence of certain combinations of midline defects or represent defined subunits of the midline developmental field.

169 citations


Journal ArticleDOI
TL;DR: It was revealed that regaining of weight was associated with the reappearance of sleep apnea syndrome, although the great majority of the patients still felt, subjectively, that they were well and did not suffer from recurrence of the sleep Apnea syndrome.

158 citations


Journal ArticleDOI
TL;DR: In most of the patients treated with the active ingredients, total elimination of the parasites was achieved within the first 10 days of treatment.
Abstract: Background: A controlled study of the efficacy of topical paromomycin sulfate (PR) and methylbenzethonium chloride (MBCI) in cutaneous leishmaniasis (CL) has not yet been performed. Objective: The therapeutic effect of an ointment containing 15% PR and either 12% or 5% MBCI (15/12 or 15/5 P-ointment) on patients suffering from Old World CL was examined in a randomized, double-blind, cross-over study. Methods: Thirty-nine patients with Old World CL caused by Leishmania major were treated topically, twice daily, for 10 to 20 days with 15/12 or 15/5 P-ointment and 10 to 20 days with a placebo ointment to achieve a total of 30 days of treatment in all groups. Results: In the P-ointment-treated groups, 74.2% (29 of 39 patients) of the patients were cured versus 26.6% (4 of 15 patients) in the placebo-treated group. Little difference was found between the 15/12 and 15/5 P-ointment groups. Conclusion: In most of the patients treated with the active ingredients, total elimination of the parasites was achieved within the first 10 days of treatment.

154 citations


Journal ArticleDOI
TL;DR: Echocardiographic, radionuclide and experimental hemodynamic observations have provided evidence that heart failure and pulmonary edema after envenomation are multifactorial with diminished systolic performance following the initially increased left ventricular contractility and decreased ventricular diastolic compliance.
Abstract: Scorpion envenomation is a common medical problem and life hazard in many countries of the world. Scientific investigations have addressed the interrelationship between the stimulatory effects of the venom on the autonomic nervous system and adrenals and the subsequent effects of released transmitters on the cardiovascular system. A number of clinical cardiovascular syndromes may dominate the initial clinical presentation after envenomation: the syndromes usually vary with the age of the victim, the size of the offender and the season. Central nervous system dysfunction is seen in children but rarely observed in adults; if accompanied by severe hypertension the clinical picture is consistent with acute hypertensive encephalopathy. Heart failure, pulmonary edema or a shock-like syndrome has been observed in 25% and hypertension in 30% to 77% of our patients. The electrocardiographic abnormalities recorded in the majority of the patients after envenomation include an "acute myocardial infarction-like pattern." Rhythm disturbances are frequent but conduction abnormalities are rare. Echocardiographic, radionuclide and experimental hemodynamic observations have provided evidence that heart failure and pulmonary edema after envenomation are multifactorial with diminished systolic performance following the initially increased left ventricular contractility and decreased ventricular diastolic compliance. Clinical laboratory data reporting increased catecholamine metabolite excretion and elevated plasma renin and aldosterone are consistent with the stimulatory effects of the venom on the autonomic nervous system. Treatment, including our experience with vasodilators and calcium channel blockers, is reviewed.

135 citations


Journal ArticleDOI
TL;DR: It is proposed that the mutation of 11 beta-hydroxylase deficiency in Jews from Morocco may have originated in either the ancient Jewish settlers or the native Berber tribes who lived in the region of the Atlas Mountains in the southern region of Morocco before the destruction of the Second Temple by the Romans.
Abstract: Steroid 11 beta-hydroxylase deficiency is relatively frequent in Israel among North African Jews. Over a 39-year period, 38 affected individuals from 25 families were diagnosed. Nineteen families came from Morocco, and in another 2, one parent came from Morocco (80% of all parents). Demographic studies showed that most of their grandparents were born in the region of the Atlas Mountains. In Israel, the overall incidence of the disorder is estimated between 1 in 30,000 to 1 in 40,000 births, but in offspring of Moroccan Jews the ratio is 1 in 5,000 to 1 in 7,000, with an allele frequency of 1 in 70 to 1 in 84 and a carrier frequency of 1 in 35 to 1 in 42. The clinical expression is characterized by a wide range of variability in the signs of androgen and mineralocorticoid excess. Virilization in the female ranged from enlarged clitoris in the mildest forms, to markedly hypertrophied clitoris with penile urethra and fused labial-scrotal folds in the most severe forms. Hypertension causing vascular accidents and death was observed in both severe and mildly virilized patients, whereas masculinized females were sometimes normotensive. Based on historical evidence, the origin of the ancestors, and the onomastic analysis of the families surnames, we propose that the mutation of 11 beta-hydroxylase deficiency in Jews from Morocco may have originated in either the ancient Jewish settlers or the native Berber tribes who lived in the region of the Atlas Mountains in the southern region of Morocco before the destruction of the Second Temple by the Romans, in the year 70 C.E.

134 citations


Journal ArticleDOI
TL;DR: This study evaluated shortand long‐term effects of courses in gerontology and geriatrics on changes in knowledge, attitudes, and work preferences among medical, nursing, and social work students in Germany.
Abstract: This study evaluated shortand long‐term effects of courses in gerontology and geriatrics on changes in knowledge, attitudes, and work preferences among medical, nursing, and social work students in...

Book ChapterDOI
TL;DR: In this paper, the authors used double exposure holography to construct a sphere trajectory based on a relatively wide range of Reynolds numbers, and evaluated the sphere drag coefficient for different Reynolds numbers.
Abstract: A shock tube facility was used for inducing relatively high acceleration on small spheres laid on the shock tube floor. The acceleration resulted from the drag force imposed by the post shock wave flow. Using double exposure holography, the sphere trajectory could be constructed accurately. Based upon such trajectories, the sphere drag coefficient was evaluated for a relatively wide range of Reynolds numbers (6000≤ Re ≤ 101000). It was found that the value obtained for the sphere drag coefficient were significantly larger than those obtained in a similar steady flow case.

Journal ArticleDOI
TL;DR: Two Spirulina platensis strains, SP-G and SP-RB, resistant and sensitive to photoinhibition of photosynthesis, respectively, were grown outdoors in dense cultures and under different photon fluxes provided by shading.
Abstract: Two Spirulina platensis strains, SP-G and SP-RB, resistant and sensitive to photoinhibition of photosynthesis, respectively, were grown outdoors in dense cultures and under different photon fluxes provided by shading. Cultures of both strains grown under full sunlight were more resistant to photoinhibition than those grown under nets with 15-50% decreases in the incident photon flux. Cultures grown outdoors were more resistant to photoinhibition than the laboratory ones. At noon, the photosynthetic activity, as expressed by O2 evolution, was higher for cultures grown under 50% shade, as compared with unshaded cultures. Productivity of the shaded cultures, in terms of biomass produced per day, was always higher when the cultures were protected from photoinhibition. Key-words: Spirulina; blue-green algae; cyanobacteria; photoadaptation; photoinhibition; photosynthesis; productivity; biomass.

Journal ArticleDOI
TL;DR: Part 1 Two views on cognitive musicology: artificial intelligence and music - cornerstone of cognitive musicological, O. Laske beyond computational musicology and an architecture for an intelligent tutoring system.
Abstract: Part 1 Two views on cognitive musicology: artificial intelligence and music - cornerstone of cognitive musicology, O. Laske beyond computational musicology, P. Kugel. Part 2 General problems in modeling musical activities: representing listening behaviour - problems and prospects, S.W. Smoliar symbolic and sonic representations of sound-object structures, B. Bel music structures - interleaving the temporal and hierarchical aspects in music, B. Balaban on designing a typed music language, E.B. Blevis, et al logical representation and induction for computer assisted composition, F. Courtot. Part 3 Music composition: cybernetic composer - an overview, C. Ames and M. Domino Wolfgang - a system using emoting potentials to manage musical design, R.D. Riecken on the application of problem reduction search to automated composition, S.C. Marsella and C.F. Schmidt the observer tradition of knowledge acquisition, O. Laske. Part 4 Analysis: an expert system for harmonizing chorales in the style of J.S. Bach, K. Ebcioglu an expert system for harmonic analysis of tonal music, H.J. Maxwell on the algorithmic representation of musical style, D. Cope. Part 5 Performance: Bol processor grammars, B. Bel and J. Kippen a new approach to music through vision, S. Ohteru and S. Hashimoto. Part 6 Perception: analyzing and representing musical rhythm, C. Linster on the perception of metre, B.O. Miller, et al the quantization problem - traditional and connectionist approaches, P. Desain and H. Honing. Part 7 Learning and tutoring: an architecture for an intelligent tutoring system, M.J. Baker a knowledge intensive approach to mcachine learning in tonal music, G. Widmer.

Journal ArticleDOI
01 Apr 1992-The Auk
TL;DR: Sensitivity analysis of model input variables indicated that oxygen extraction and expired air temperature are the most important physiological variables in a bird's water budget and can profoundly influence flight duration.
Abstract: -We examined the physiological limitations to flight duration in small migrating birds with a computer-simulation model. Given preflight body mass, fat and water contents, and flight-path meteorological data, we calculated water and energy budgets and possible flight time. The model can be applied to birds of any size that migrate by flapping flight. As an example, we simulated the flight of small Palearctic passerines (body mass = 10 g) during their annual migration over the Sahara desert. Sensitivity analysis of model input variables indicated that oxygen extraction and expired air temperature are the most important physiological variables in a bird's water budget and can profoundly influence flight duration. This manifests the importance of: (1) efficient cooling in the nasal passages of flying birds; and (2) the choice of flight altitude (which affects both ambient air temperature and expired air temperature). The model predicted that: (1) Prior to migration, these birds must have stored fat comprising at least 22% of their initial body mass; otherwise, they cannot complete their journey. (2) In relatively fat birds (stored fat > 0.22 body mass), dehydration rather than energy will limit flight duration. (3) Birds should fly at an altitude not exceeding 1,000 m to cross the Sahara successfully. (4) Even in low-flying fat birds, flight duration will be limited by their stringent water budget. The model further predicted that small passerines cannot cross the Sahara in a 30to 40-h nonstop flight, as commonly accepted, but should confine flying to the cooler hours (i.e. nights) and rest during the day in order to avoid elevated rates of water loss due to higher ambient air temperatures. Available data and observations of birds trapped at stopover sites in the Sahara support these predictions. Received 26 February 1991, accepted 13 January 1992. LONG-DISTANCE flight over seas or deserts is perhaps the most risky and physiologically challenging event in the life cycle of migratory birds (Moreau 1961, Wilson 1981). Reports of high attrition among migrants and of exhausted birds found severely dehydrated and/or fat depleted (Serle 1956, Odum et al. 1964, Rogers and Odum 1964, Johnston 1968, Wilson 1981) raised the question: Is water or energy the greater physiological limitation to bird flight duration? Energy, rather than water, is currently considered the major factor limiting bird flight duration because dehydration can be avoided by flying at high altitudes where air temperatures are low (Blem 1976, Torre-Bueno 1978, Skadhauge 1981, Dawson 1982, Biesel and Nachtigall 1987, Biebach 1990). However, this paradigm has not been substatiated with empirical field

Journal ArticleDOI
TL;DR: The results mean that root development, and especially lateral root initiation, depends on the integrated effects of the local environment and the internal correlative relations between the roots.
Abstract: Roots are known to respond to favourable nutrient conditions by increased initiation and growth of lateral roots. The problem studied here was to what extent does this local developmental response depend on the environments of other roots on the same plant. Such dependence could allow for an optimal allocation of resources required for root growth in unpredictable, heterogeneous soils. Pea seedlings (Pisum sativum var. arvense cv. Dun) were pruned and grown to have two equal root systems, each in an individual container. As expected, these roots responded by increased development to a wide range of nutrient solution concentrations. The local development of these roots, expressed by their dry weight, was a function of the relative rather than the absolute conditions in which they were grown: roots in a given environment developed more rapidly if other roots on the same plant were in poorer than if they were in richer nutrient conditions. The number of lateral initials doubled within 3d after the roots were exposed to optimal nutrient conditions, before any dry weight differences could be detected. This rapid root initiation was also a function of the conditions other roots of the same plant were in. These results mean that root development, and especially lateral root initiation, depends on the integrated effects of the local environment and the internal correlative relations between the roots.

Journal ArticleDOI
TL;DR: N europaea assimilates CO2 anaerobically into cell material in the presence of nitrite (0.5–1.0 mM), pyruvate and ammonia, and is sensitive to ionophores, FCCP being the most effective.
Abstract: Nitrosomonas europaea is capable of maintaining an anaerobic metabolism, using pyruvate as an electron donor and nitrite as an electron acceptor; utilization of nitrite depends upon supply of both pyruvate and ammonia. The role of ammonia in this reaction was not determined. N europaea also assimilates CO2 anaerobically into cell material in the presence of nitrite (0.5–1.0 mM), pyruvate and ammonia. This reaction was partially inhibited by nitrite which apparently competed with CO2 for reducing power. Anaerobic “nitrite respiration” is sensitive to ionophores, FCCP being the most effective.

Journal ArticleDOI
TL;DR: In this paper, the Cretaceous/Tertiary boundary at Hor Hahar occurs within the interval from the top of the Ghareb Formation (Maastrichtian) to just below the horizon of dark marl and clay within the overlying Taqiye Formation (Paleocene).

Journal ArticleDOI
TL;DR: In this paper, the authors review recent numerical and analytical results related to the coexistence of nonlinear wave propagation and disorder effects, mostly for soliton bearing systems, and demonstrate that nonlinear transmission strongly depends on the soliton type: results are different for dynamical, topological, and envelope solitons.

Journal ArticleDOI
TL;DR: The results suggest that attenuation of beta-adrenergic receptor-coupled Gs protein function, which is common to both antidepressant and antibipolar treatments, may be the mechanism underlying their antidepressant therapeutic efficacy.

Journal ArticleDOI
TL;DR: The quantum-mechanical electrical conductance of a lattice of wires as a function of the bond-occupation probability p is studied and an analytic expression for the energy dispersion relation of the Bloch electrons, which couples all the transverse momenta is obtained.
Abstract: Motivated by concepts of classical electrical percolation theory, we study the quantum-mechanical electrical conductance of a lattice of wires as a function of the bond-occupation probability p. In the ordered or ballistic case (p=1), we obtain an analytic expression for the energy dispersion relation of the Bloch electrons, which couples all the transverse momenta. We also get closed-form expressions for the conductance ${\mathit{g}}_{\mathit{N}\mathit{L}}$ of a finite system of transverse dimension ${\mathit{N}}^{\mathit{d}\mathrm{\ensuremath{-}}1}$ and length L (with d=2 or 3). In the limit L\ensuremath{\rightarrow}\ensuremath{\infty}, the conductance is quantized similarly to what is found for the conductance of narrow constrictions. We also obtain a closed-form expression for the conductance of a Bethe lattice of wires and find that it has a band whose width shrinks as the coordination number increases. In the disordered case (p1), we find, in d=3 dimensions, a percolation transition at a quantum-mechanical threshold ${\mathit{p}}_{\mathit{q}}$ that is energy dependent but is always larger than the classical percolation threshold ${\mathit{p}}_{\mathit{c}}$. Near ${\mathit{p}}_{\mathit{q}}$ (namely, for small values of \ensuremath{\Vert}\ensuremath{\Delta}\ensuremath{\Vert}==\ensuremath{\Vert}p-${\mathit{p}}_{\mathit{q}}$\ensuremath{\Vert}), the mean quantum-mechanical conductance 〈${\mathit{g}}_{\mathit{L}}$〉 of a cube of length L follows the finite-size-scaling form 〈${\mathit{g}}_{\mathit{L}}$(p)〉\ensuremath{\approxeq}${\mathit{L}}^{\mathit{d}\mathrm{\ensuremath{-}}2\mathrm{\ensuremath{-}}\mathit{t}/\ensuremath{ u}}$F(\ensuremath{\Delta}${\mathit{L}}^{1/\ensuremath{ u}}$), where the scaling function F and the critical exponent \ensuremath{ u} are different from their classical analogues.Our numerical estimate of the critical exponents is \ensuremath{ u}=0.75\ifmmode\pm\else\textpm\fi{}0.1 and t=\ensuremath{ u} in accordance with results of nonlinear \ensuremath{\sigma} models of localization. The distribution of the conductance undergoes a substantial change at threshold. The conductance in the diffusive (metallic) regime in d=3 dimensions follows Ohm's law (it is proportional to L). As p\ensuremath{\rightarrow}1, the crossover between the metallic and the ballistic regimes is governed by the scaling law 〈${\mathit{g}}_{\mathit{L}}$(p)〉\ensuremath{\approxeq}${\mathit{L}}^{2}$K(L(1-p)). No percolation transition is found for d=2 but as p\ensuremath{\rightarrow}1, the crossover between the quasimetallic and the ballistic regimes is governed by a similar scaling law.

Journal ArticleDOI
TL;DR: The present findings indicate that a colon-specific potent carcinogen interferes with the biological expression of 1,25(OH)2D3 and that vitamin D administered prior to a carcinogenic insult is able to reduce significantly the incidence of colon tumors, presumably acting as an antiproliferative or differentiation-promoting agent.
Abstract: The intriguing observation has been made that 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] receptors are present in tissues not involved in calcium homeostasis and that 1,25(OH)2D3 exerts an antiproliferative, differentiation-promoting action in a variety of cancer cell lines, including cells of the large intestine. It was therefore deemed of interest to study 1,25(OH)2D3 expression and biological activity in a murine model of colon carcinogenesis. Colon carcinogenesis was induced in male rats by the sequential administration of 1,2-dimethylhydrazine dihydrochloride (DMH). Levels and binding characteristics of 1,25(OH)2D3 receptors were assessed in control and DMH-treated rat colonic mucosal high-speed supernatants. In concurrent studies, 1,25(OH)2D3 was administered (s.c., 400 ng/rat) prior to, together with and after DMH challenge and the activity of ornithine decarboxylase (ODC), a growth-related DMH-induced enzyme, was determined in colonic cytosols. Serum Ca2+ levels were measured concurrently. Rats submitted to identical treatment schedules were killed 10 weeks after termination of DMH administration and the whole colon was opened and examined for tumors. The results show that (i) rat colonic mucosa possesses a single class of high-affinity 1,25(OH)2D3 receptors; (ii) DMH administration provokes a marked reduction (50%) in 1,25(OH)2D3 binding sites without affecting Kd values; (iii) DMH administered concurrently with 1,25(OH)2D3 suppressed the vitamin D-induced hypercalcemia and restored serum Ca2+ concentrations to basal levels; and (iv) 1,25(OH)2D3 delivered prior to DMH challenge obliterated the typical DMH-induced early colonic ODC activity peak and markedly reduced (50%) the number of colon adenocarcinomas. The present findings indicate that a colon-specific potent carcinogen interferes with the biological expression of 1,25(OH)2D3 and that vitamin D administered prior to a carcinogenic insult is able to reduce significantly the incidence of colon tumors, presumably acting as an antiproliferative or differentiation-promoting agent.

Journal ArticleDOI
TL;DR: In this paper, the seeds of four date palm (Phoenix dactylifera L.) cultivars, Dekel Noor, Zahidi, Medjool and Halawy, grown in the Arava Valley of southern Israel were analyzed for their inorganic and some organic constituents.
Abstract: The seeds of four date palm (Phoenix dactylifera L.) cultivars, Dekel Noor, Zahidi, Medjool and Halawy, grown in the Arava Valley of southern Israel were analyzed for their inorganic and some organic constituents. The following average values were obtained for the four cultivars on a dry-weight basis: protein 5.60%, oil 8.15%, fiber 16.13%, and ash 1.13%. Analysis of the mineral elements in the ash gave the following average values: Ca, 1.55%; Na, 0.97%; Mg, 8.07%; K, 27.60%; Fe, 0.73%; Cu, 0.13% and Mn, 0.08%. The oil exhibited the following characteristics (average for the four cultivars): acid value ∼1.04, iodine value 49.5, saponification value 221.0, and unsaponifiable matter 0.8%. Gas-liquid chromatography revealed that the major unsaturated fatty acid was oleic acid (42.3%), while the main saturated fatty acid was lauric (21.8%). Myristic, palmitic and linoleic acids were also found, average values being 10.9, 9.6 and 13.7%, respectively. Potential uses for date seed oil are considered for cosmetic, pharmaceutical and related specialty products, and to a lesser degree for food products.

Journal ArticleDOI
TL;DR: In this article, two experimentally derived models are developed-one for practical use and the other for scientific understanding, and the correlation of prediction with measurement is on the order of 90% or more, over large dynamic ranges of meteorological parameters.
Abstract: Although optical turbulence is usually modeled with micrometeorology, it is shown here that this can be done successfully too with macrometeorology using meteorological parameters measured with standard weather stations and predicted in standard weather forecasts. This makes it possible to predict C2n according to weather forecast. Two experimentally derived models are developed-one for practical use and the other for scientific understanding. Correlation of prediction with measurement is on the order of 90% or more, over large dynamic ranges of meteorological parameters. One interesting aspect of these measurements is the statistical evidence that scintillations are affected by aerosols, particularly under conditions of high total aerosol cross-sectional area. Various explanations for effects of aerosols on C2n and its measurement are suggested. In addition, validity of the models was examined, and experimental comparisons in two very different climates and surface conditions are presented. High correlation is found in both cases between prediction and measurement.

Journal ArticleDOI
TL;DR: The major physiological principles involved in mass production of photoautotrophic microalgae outdoors relate to sustained trapping of solar energy in as high an efficiency as possible throughout the year as mentioned in this paper.
Abstract: The major physiological principles involved in mass production of photoautotrophic microalgae outdoors relate to sustained trapping of solar energy in as high an efficiency as possible throughout the year.

Journal ArticleDOI
TL;DR: In this paper, the authors concluded that Rangitawa tephra represents a major eruptive event in the Taupo Volcanic Zone most probably associated with eruption of the Whakamaru-group ignimbrites (0.35−0.39 Ma) or less likely the Paeroa Range Group Ignimbrites(0.36-0.38 Ma).

Journal ArticleDOI
TL;DR: The catalytic machinery of these AHAS isozymes is entirely contained within the large subunits, and nearly all of the properties of the intact AHAS isozyme I or III can be reconstituted by mixing extracts containing the respective large and small subunits.
Abstract: The acetohydroxy acid synthase (AHAS) isozymes from enterobacteria are each composed of a large and small subunit in an alpha 2 beta 2 structure. It has been generally accepted that the large (ca. 60-kDa) subunits are catalytic, while the small ones are regulatory. In order to further characterize the roles of the subunits as well as the nature and the specificities of their interactions, we have constructed plasmids encoding the large or small subunits of isozymes AHAS I and AHAS III, each with limited remnants of the other peptide. The catalytic properties of the large subunits have been characterized and compared with those of extracts containing the intact enzyme or of purified enzymes. Antisera to the isolated subunits have been used in Western blot (immunoblot) analyses for qualitative and semiquantitative determinations of the presence of the polypeptides in extracts. The large subunits of AHAS isozymes I and III have lower activities than the intact enzymes: Vmax/Km is 20 to 50 times lower in both cases. However, for AHAS I, most of this difference is due to the raised Km of the large subunit alone, while for AHAS III, it is due to a lowered Vmax. The substrate specificities, R, of large subunits are close to those of the intact enzymes. The catalytic activity of the large subunits of AHAS I is dependent on flavin adenine dinucleotide (FAD), as is that of the intact enzyme, although the apparent affinities of the large subunits alone for FAD are 10-fold lower. Isolated subunits are insensitive to valine inhibition. Nearly all of the properties of the intact AHAS isozyme I or III can be reconstituted by mixing extracts containing the respective large and small subunits. The mixing of subunits from different enzymes does not lead to activation of the large subunits. It is concluded that the catalytic machinery of these AHAS isozymes is entirely contained within the large subunits. The small subunits are required, however, for specific stabilization of an active conformation of the large subunits as well as for value sensitivity.

Journal ArticleDOI
TL;DR: It is concluded that long‐term therapy, even with relatively conventional doses of inhaled BDP may cause reduction in the normal physiological secretion of cortisol, which may reflect partial suppression of the pituitary—adrenal axis.
Abstract: We assessed the effect of long-term therapy with inhaled beclomethasone dipropionate (BDP) on the pituitary-adrenal axis, by measuring the integrated concentration (IC) of plasma cortisol in eight children with asthma (age, 6-16 years) who regularly used inhaled BDP in doses ranging from 8 to 26.5 micrograms/kg (200-450 micrograms/day) for 6 months to 4 years. The control group included six children (age, 6-16 years) who had the IC of plasma cortisol measured as part of an endocrinological evaluation and were found to be healthy. Cortisol concentration was measured in blood samples collected continuously over a 24-hr period. Mean IC of plasma cortisol in the study group was significantly lower than in the healthy controls (mean +/- SD, 4.9 +/- 3.3 vs 9.1 +/- 1.9 micrograms/mL; P less than 0.02). Cortisol response to 0.25 mg ACTH (iv) was abnormal in one of the eight BDP-treated patients. No correlation was found between IC of plasma cortisol and the BDP dose, severity of asthma, height percentile, or the Tanner stage. We conclude that long-term therapy, even with relatively conventional doses of inhaled BDP may cause reduction in the normal physiological secretion of cortisol. The clinical relevance of low IC of plasma cortisol is not clear, but it may reflect partial suppression of the pituitary-adrenal axis.

Journal ArticleDOI
TL;DR: Analysis of data derived from the Baltimore-Washington Infant Study of congenital cardiovascular malformations supports the observation that "syndromic" ECD tends to be of the complete atrioventricular canal type and is less frequently associated with left cardiac anomalies than the isolated form.
Abstract: The isolated occurrence of endocardial cushion defect (ECD) has been suggested to differ from its occurrence within the context of a syndrome, with regard to the nature (complete or partial) of the defect and the associated cardiovascular malformations. Analysis of data derived from the Baltimore-Washington Infant Study of congenital cardiovascular malformations supports the observation that "syndromic" ECD tends to be of the complete atrioventricular canal type and is less frequently associated with left cardiac anomalies than the isolated form. However, each syndrome has a unique impact on the overall cardiovascular "phenotype", including the ECD. This is especially true for Down and Ivemark syndromes, which are most frequently associated with ECD, but also for other syndromes as well. It is also suggested that isolated ECD is specifically associated with gastrointestinal and urinary tract anomalies. However, in Down syndrome ECD appears to be a specific cardiovascular expression of the trisomic state that is unrelated to other noncardiac malformations. Additional information on the association of ECD with other less common genetic syndromes is needed in order to further investigate the possible genetic basis of this cardiac defect.

Journal ArticleDOI
TL;DR: This review focuses on two basic approaches: externally regulated systems (utilizing triggers such as magnetism, ultrasound, temperature and electricity), and self-regulated systems ( utilizing pH-sensitive polymers, enzyme-substrate reactions, competitive binding, and antibody interactions).