Influence of cadmium and nickel on growth, net photosynthesis and carbohydrate distribution in rice plants

1992

Six day old rice seedlings (Oryza sativa L. cv. Bahía) were grown for 5 or 10 days in a nutrient solution with either Cd (0.01, 0.1 mmol/l) or Ni (0.1, 0.5 mmol/l). Both Cd and Ni reduced the length of shoots and roots depending on the concentration and type of ion tested. On the other hand, the dry weight to fresh weight ratio was increased by heavy metal treatments, especially in the aerial part of 0.5 mmol/l Ni treated plants. The application of 0.1 mmol/l Cd and 0.5 mmol/l Ni to the seedlings produced an inhibition of the transport of carbohydrate reserves from the seeds from which plants were developing, to the rest of the plant. Net photosynthesis was also inhibited in treated plants.…

L'allocation du temps en cours d'études: le cas des étudiants brésiliens, espagnols et français

1992

International audience

Theory-based improvements of continuous polymer fractionation demonstrated for poly(carbonate)

1992

For the first time, a quantitative theoretical analysis (liquid/liquid phase equilibria treated by means of the continuous thermodynamics) of the operating characteristics of continuous polymer fractionation (CPF) was performed. The results of these calculations were compared with data published for CPF of polyethylene. It turned out that the efficiency of the conventional CPF corresponds to approximately two theoretical plates only. For this reason, several improvements, suggested by theoretical considerations, were realized experimentally, for which purpose the system dichloromethane/diethylene glycol/bisphenol-A polycarbonate was chosen. The pulsating sieve-bottom column was replaced by …

Blood flow velocity waveforms of the middle cerebral artery and abnormal neurological evaluations in live-born fetuses with absent or reverse end-dia…

1992

Abstract We studied 37 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical arteries with respect to the mode of delivery, fetal acidosis, resistance index of the middle cerebral arteries, and abnormal neurological evaluation at the time of discharge from the department of pediatrics. A control group with normal umbilical artery flow velocity waveforms was matched for gestational age. Fetuses with AREDFV were delivered almost exclusively by cesarean section, in most cases due to fetal distress. Metabolic changes with decreased base excess values were found more often in fetuses with AREDFV, but no difference could be detected with respect to severe fetal ac…

The disenchantment of professionals in a new, implemented model of primary health care in Spain: A structural equations model

1992

Abstract A new model of primary health care has been progressively implemented in Spain. Previous research (Peiro and Gonzalez-Roma 1991) suggested that the implementation of this new model has produced a kind of disenchantment—that is, an experience of negative surprise—among health care professionals involved. In the present paper, a structural equations model about the antecedents and consequences of the experience of surprise is tested in a sample of 432 health care professionals working in 44 Primary Health Care Teams (PHCT). The results obtained showed that the number of uncovered functions in the PHCTs, the discrepancy between actual and desired time allocation, and the assessment of…

Resonant formation of pionic atoms with neutron collisions

1992

We study the {ital n}+{ital A}{r arrow}({ital A}{prime}{pi}{sub {ital b}}{sup {minus}}){r arrow}{ital n}+{ital A} reaction, or resonant formation of pionic atoms, with neutron scattering. We evaluate the contribution of the interference of this reaction channel in {sup 40}Ca and {sup 208}Pb to the elastic scattering amplitude at backward angles. The ratio of signal to the background at 80{degree} is about 10{sup {minus}3}, and we estimate that the ratio does not improve at higher angles, hence making this reaction impractical. Our findings have repercussions on a similar reaction now running at the Indiana University Cyclotron Facility.

Compound odontoma erupting in the mouth: 4-year follow-up of a clinical case

1992

A case of a compound odontoma erupting in the oral cavity is presented: a follow-up study of 4 yr has been performed evaluating the possible relationship with a previous dental trauma. A discussion is presented concerning the etiologic aspects, clinical signs, diagnostic aids and therapeutic approaches to this type of lesion.

Animalité et végétalité dans les représentations de l’hérédité

1992

L'hypothese que nous soutiendrons se resume en peu de mots. Depuis le milieu du XIXe siecle, et jusqu'en 1960 au moins, l'heredite n'a cesse de se confirmer comme l'un des problemes centraux, et sans doute comme "le" probleme theorique central, de la biologie moderne. Aussi est-il comprehensible que, par-dela les vicissitudes et les succes de la science empirique de l'heredite, la notion ait suscite toutes sortes de reflexions generales sur la nature meme de la vie. Le concept d'heredite s'est cherche dans une serie de philosophemes qui rappellent etrangement la trilogie aristotelicienne de l'âme. On peut en effet assez aisement reperer des representations vegetalisantes, animalisantes et i…

Weight Gain Associated with Cinnarizine

1992

OBJECTIVE: To report four cases of cinnarizine-induced weight gain. DATA SOURCES: Case reports from a local obesity center and review articles. DATA EXTRACTION: Data were abstracted from spontaneous comments made by patients to one of the authors, who was a doctor at the clinic, and reviewed by the remaining authors. DATA SYNTHESIS: We reviewed the cases of four women, aged 50–57 years without endocrine or metabolic pathologies, that showed weight gain associated with the intake of cinnarizine for one to two years. No other drugs usually were administered during the period in which the women gained weight, although in two cases cinnarizine was associated with dihydroergocristine in the same…

“Comic Irony and Contradiction in Kurt Vonnegut’s Slaughterhouse-Five”

1992

International audience

Partition Behavior of Anilines in Bulk‐Phase and High‐Performance Liquid Chromatographic Systems: Influence on Correlation with Biological Constants

1992

Abstract The partition behavior of a mixed series of ring‐substituted anilines in reversed‐phase high‐performance liquid chromatographic systems is substantially different from that observed in a classical bulk‐phase partition system with n ‐heptane as the aprotic reference solvent. On the basis of the equivalence of each ring substituent in the p ‐straight‐chain methylene groups (ν value) as a function of the fraction of organic solvent (acetonitrile or methanol) in the mobile phase, the biased partition behavior for imperfect homologues and heterologues is verified relative to that of perfect homologues. This behavior was tentatively attributed, mainly, to differences in the hydrogen bond…

Klinische Relevanz der Anti-CEA-Immunszintigraphie mit dem99mTc-markierten monoklonalen Antikörper BW 431/26

1992

The results of 119 radioimmunoscintigraphies (RIS) in 113 patients with the 99mTc-labeled monoclonal anti-CEA-antibody BW 431/26 (Behring) have been analysed. The aim of our study was the estimation of the method's sensitivity and specificity under different aspects to find out for which indications and questions the 99mTc-RIS is useful. Colorectal primary tumours in 19 patients were scintigraphically detected with a sensitivity of 83% and a specificity of 100%; 3 out of 7 other tumour sites were localised correctly. 55 patients were examined during the follow-up of colorectal cancer. There were 17 out of 22 true positive findings of local recurrences (sensitivity 77%, specificity 88%). Liv…

Aplasia of the retinal vessels combined with optic nerve hypoplasia, neonatal epileptic seizures, and lactic acidosis due to mitochondrial complex I …

1992

A newborn male with mitochondrial complex I deficiency suffered from neonatal epileptic seizures, which later developed into infantile spasms. The infant was blind due to aplasia of the retinal vessels and hypoplasia of the optic nerve. There was congenital lactic acidosis, which persisted in later life. The boy was microcephalic and retarded. Muscular hypotonia later shifted to spasticity. Succinic acid was increased in urine. We assume that the aplasia of the retinal vessels is due to damage of the retinal ganglion cells caused by the mitochondrial disease in the first 3 to 4 months of pregnancy.

Neutrino mixing and future accelerator neutrino experiments

1992

Phylogenetic reconstruction of the Drosophila obscura group, on the basis of mitochondrial DNA

1992

We have constructed restriction-site maps of the mtDNAs in 13 species and one subspecies of the Drosophila obscura group. The traditional division of this group into two subgroups (affinis and obscura) does not correspond to the phylogeny of the group, which shows two well-defined clusters (the Nearctic affinis and pseudoobscura subgroups) plus a very heterogeneous set of anciently diverged species (the Palearctic obscura subgroup). The mtDNA of Drosophila exhibits a tendency to evolve toward high A+T values. This leads to a "saturation" effect that (1) begets an apparent decrease in the rate of evolution as the time since the divergence of taxa increases and (2) reduces the value that mtDN…

A status report

1992

Abstract This article considers the financial and proprietary considerations applicable to computer crime, computer security and personal privacy. The failure to take proper precautions in these areas can lead to major operational problems and substantial loss of assets. Developments in the late 1980s, particulary the discovery by the public press of so-called ‘computer viruses’, indicates the need for counsel representing suppliers and users to understand the basic technology involved and the legal implications. Such a report by Robert Bigelow was first published in CLSR in March 1989. He has now updated and revised the text which will be featured in several parts. In the first parts the l…

13C NMR spectra of eudesmane derivatives

1992

The 13C NMR spectral data of 18 eudesmane derivatives, mainly acids and esters of natural and synthetic origin, are reported, and the γ-effect of the epoxide ring in two diastereoisomeric epoxy esters is discussed.

Sarcoma of the pulmonary artery: Report of two cases and a review of the literature

1992

Primary tumours of the pulmonary arteries are rare neoplasms seldom diagnosed during the patient's life time. We report on two cases of pulmonary artery sarcomas diagnosed during life time of the respective patients in intra-operative frozen sections by histopathological examination. Case 1 was of a 55-year-old man with a fibrosarcoma originating from the main pulmonary trunk. Case 2 was of a 43-year-old woman with a malignant fibrous histiocytoma originating from the right pulmonary artery. In both patients a radical tumour resection under cardiopulmonary bypass was attempted. Both patients, however, had a local tumour recurrence and died 18 months (patient 1) and 6 months (patient 2) afte…

Conscious knowledge and changes in performance in sequence learning: Evidence against dissociation.

1992

International audience; Two experiments examined the relation between explicit knowledge and motor performance on the serial reaction time task developed by Nissen and Bullemer (1987). Tests of free recall and recognition of sequence components revealed that reliable explicit knowledge was acquired after an amount of practice that was hardly sufficient to improve mean motor performance. In addition, reaction time improvement was limited to the ending trials of the 3- and 4-trial sequence components that Ss recalled or recognized. These results were replicated in Experiment 3, in which Ss were trained under attentional distraction in the task developed by Cohen, Ivry, and Keele (1990). Overa…

Hyperfine-structure measurements on trapped Pb II.

1992

The 6${\mathit{P}}_{3/2}$-6${\mathit{P}}_{1/2}$ magnetic dipole resonance transition in ${\mathrm{Pb}}^{+}$ has been observed by cw laser excitation of an ion cloud stored in a Paul trap and subsequent detection of the fluorescence radiation. From the hyperfine-structure splitting of the spectrum we determine the A factor for the ground state, A(${\mathit{P}}_{1/2}$)=12.967(13) GHz, and the excited state, A(${\mathit{P}}_{3/2}$)=0.580(3) GHz. From a contamination of $^{208}\mathrm{Pb}$ in our sample we derived the $^{207}\mathrm{Pb}^{+}$${\mathrm{\ensuremath{-}}}^{208}$${\mathrm{Pb}}^{+}$ isotope shift [\ensuremath{\Delta}\ensuremath{\nu}=311(14) MHz]. A small electric quadrupole admixture …

Application of the star-product method to the angular momentum quantization

1992

We define a *-product on ℝ3 and solve the polarization equation f*C=0 where C is the Casimir of the coadjoint representation of SO(3). We compute the action of SO(3) on the space of solutions. We then examine the case of non-zero eigenvalues of C, in order to find finite-dimensional representations of SO(3). Finally, we compute \(\sqrt C *\sqrt C \) as an asymptotic series of C. This gives an explanation of the use of the star square root of C in a paper by Bayen et al. instead of its natural square root.

Factors affecting shoot proliferation and vitrification inDigitalis obscura cultures

1992

Variations of composition and consistency of the culture medium and time of exposure to growth regulators were assayed to optimize normal caulogenic response ofDigitalis obscura hypocotyls cultured in vitro. The effects of the culture conditions on physiologic changes related to vitrification of the regenerated plants were also investigated. Liquid medium increased the bud-forming capacity of the explants but induced buds failed to develop into shoots and showed symptoms of vitrification. On agar-solidified media, maximum multiplication rates were achieved with 0.7% agar. Increasing agar concentration reduced vitrification but lowered the propagation rate. Changes in the strength of the mac…

Conservative surgery of renal cell tumors in 140 patients: 21 years of experience.

1992

Operative method, course and complications were analyzed retrospectively in 140 patients who underwent a conservative operation for renal tumor between June 1969 and December 1990. In 53 patients (20 women and 33 men, mean age 61.2 years, range 38 to 77 years, with 49 renal cell carcinomas and 4 benign renal tumors) there was an imperative indication for an organ preserving operation because nephrectomy would have made dialysis obligatory. In 87 patients (29 women and 58 men, mean age 53.7 years, range 27 to 74 years, with 72 renal cell carcinomas and 15 benign renal tumors) the tumor was conservatively resected in the presence of a normal contralateral unit (elective indication) and 68 of …

Floquet spectrum for two-level systems in quasiperiodic time-dependent fields

1992

We study the time evolution ofN-level quantum systems under quasiperiodic time-dependent perturbations. The problem is formulated in terms of the spectral properties of a quasienergy operator defined in an enlarged Hilbert space, or equivalently of a generalized Floquet operator. We discuss criteria for the appearance of pure point as well as continuous spectrum, corresponding respectively to stable quasiperiodic dynamics and to unstable chaotic behavior. We discuss two types of mechanisms that lead to instability. The first one is due to near resonances, while the second one is of topological nature and can be present for arbitrary ratios between the frequencies of the perturbation. We tre…

Alterations in circadian rhythm of serum thyrotropin in critically ill patients.

1992

To evaluate the 24-h pattern of serum thyrotropin (TSH) in critically ill patients, we measured serum concentrations of TSH in blood samples collected every 2 h for 24 h from nine patients (six with malignancy, two with liver cirrhosis, one with chronic renal failure), who had subnormal levels of both triiodothyronine (T3) and thyroxine (T4), in the absence of history, symptoms or signs of thyroid disease. Analysis of the data, performed using a second-order inferential statistical methodology for rhythmometry (cosinor method), demonstrated that critically ill patients still had daily oscillations of serum TSH which significantly adapted to the function approximating the circadian rhythms (…

Lepton flavour nonconservation in H0 decays

1992

Abstract We calculate the off-diagonal lepton-lepton-Higgs boson vertex induced by one-loop electroweak corrections, in the context of the standard model in which one right-handed neutrino for each family has been introduced. We find that in the presence of very heavy Majorana neutrinos the lepton-flavour-violating decays of the H0 boson can be significantly enhanced yielding observable signals at high energy collider machines.

Free trade and protection of the environment: Is the GATT in need of reform?

1992

The GATT negotiations under the Uruguay Round have almost run their course. However, consultations are certain to continue, as critics regard the GATT rules on environmental protection as inadequate. What aspects need to be reformed, and how might the initial reform measures look?

Biomechanical Loading of Achilles Tendon During Normal Locomotion

1992

Direct in vivo Achilles tendon force measurements open up new possibilities for understanding the loading of the Achilles tendon during natural locomotion. This article describes how these human experiments can be performed. The results of these experiments imply that Achilles tendon forces are unexpectedly high in certain activities (e.g., hopping) and that the rates of loading rather than the absolute magnitudes of the recorded forces may be more relevant for clinical purposes as well as for the construction of artificial tendon materials.

On the calculation of derived variables in the analysis of multivariate responses

1992

AbstractThe multivariate regression of a p × 1 vector Y of random variables on a q × 1 vector X of explanatory variables is considered. It is assumed that linear transformations of the components of Y can be the basis for useful interpretation whereas the components of X have strong individual identity. When p ≥ q a transformation is found to a new q × 1 vector of responses Y∗ such that in the multiple regression of, say, Y1∗ on X, only the coefficient of X1 is nonzero, i.e. such that Y1∗ is conditionally independent of X2, …, Xq, given X1. Some associated inferential procedures are sketched. An illustrative example is described in which the resulting transformation has aided interpretation.

Pathophysiological aspects of hyperthermia

1992

Blood flow in many rapidly growing tumors is sluggish leading to an impairment of convective heat dissipation which facilitates tumor heating compared to normal tissues. In addition, the compromised microcirculation causes a hostile metabolic micromilieu which can modulate the therapeutic effect of heat. After clinically relevant heat doses, a shut-down of tumor microcirculation is often observed creating a “heat-reservoir” and aggravating tumor hypoxia, acidosis, and substrate and energy depletion, factors which are known to greatly enhance tumor cell killing by heat. Since the mechanisms described are mostly derived from experimental results on fast-growing animal tumors, the clinical rel…

Pharmacological characterization and autoradiographic localization of histamine H2 receptors in human brain identified with [125I]iodoaminopotentidin…

1992

125I-Aminopotentidine (125I-APT), a reversible probe of high specific radioactivity and high affinity and selectivity for the H2 receptor, was used to characterize and localize this histamine receptor subtype in human brain samples obtained at autopsy. On membranes of human caudate nucleus, specific 125I-APT binding at equilibrium revealed a single component, with a dissociation constant of 0.3 nM and maximal capacity of about 100 fmol/mg of protein. At 0.2 nM, 125I-APT specific binding, as defined with tiotidine, an H2-receptor antagonist chemically unrelated to iodoaminopotentidine, represented 40-50% of the total. Specific 125I-APT binding was inhibited by a series of typical H2-receptor…

The structure of pumice: An XPS and27Al MAS NMR study

1992

In order to investigate the surface structure of pumice, an amorphous aluminosilicate, samples of pumice and of standards of silica and alumina have been studied by x-ray photoelectron spectroscopy (XPS). The effect of a mild acid leaching was also considered. The analysis of the Si 2p, Al 2p and O 1s photoelectron peaks and the Si KLL and O KLL Auger peaks indicated that pumice is formed by tetrahedral silica with some units being replaced by aluminate, AlO2−. The acid treatment decreases the alkali and the aluminate ions. X-ray photoelectron spectra of the valence band of pumices and of standards of Al2O3 and SiO2 agree with the core-level results. To support the conclusions from the XPS …

Structure and dynamics of polymer brushes near the Θ point: A Monte Carlo simulation

1992

Grafted polymer layers under variable solvent conditions are studied by Monte Carlo simulations using the bond fluctuation model. Structural information such as monomer density profiles, brush thickness, mean‐square displacement of monomers, and positions of the monomers along the chain are obtained for temperatures above, at, and below the Θ point. In particular, the scaling of the brush thickness is formulated and verified by the simulation data. At the Θ point, more extensive simulations are performed to investigate the structural and dynamical properties. While the brush thickness at the Θ point agrees very well with the scaling and self‐consistent field predictions, the latter deviate …

Photochemical Derivatization and Fluorimetric Determination of Promethazine in a FIA Assembly

1992

Abstract The flow injection fluorimetric determination of promethazine is carried out by on-line photoderivatization. The PTFE tubing is helically coiled around the lamp. An analytical procedure is proposed by using aqueous solution as carrier stream: the calibration graph is linear over the range 0.05 - 20 ppm. The influence of foreign compounds is studied and the method is applied to promethazine determination in pharmaceutical formulations.

The ratio of androstenedione: 11β-hydroxyandrostenedione is an important marker of adrenal androgen excess in women

1992

To determine if the ratio of serum androstenedione (A):11 beta-hydroxyandrostenedione (OHA) would be helpful in differentiating adrenal from ovarian hyperandrogenism.Prospective study of outpatients being evaluated for hyperandrogenism.Normal women (n = 27), those with hyperandrogenic chronic anovulation (n = 25), and 7 with adult onset of congenital adrenal hyperplasia (CAH) because of 21-hydroxylase deficiency.Fasting serum between 8:00 A.M. and 9:00 A.M. Patients with hyperandrogenic chronic anovulation and CAH received dexamethasone (DEX) 2 mg for 7 days.Serum testosterone (T), unbound T, dehydroepiandrosterone sulfate (DHEAS), A, and 11 beta-OHA by radioimmunoassay.Serum 11 beta-OHA an…

The POT1 gene for yeast peroxisomal thiolase is subject to three different mechanisms of regulation

1992

The Saccharomyces cerevisiae POT1 gene is, as are other yeast peroxisomal protein genes, inducible by fatty acids and repressible by glucose. We have now found that it is also induced during the stationary phase of the culture. To investigate these three regulatory circuits, we have studied the mRNA levels of regulatory mutants as well as the changes in chromatin structure upon gene activation. We conclude that the regulation of transcriptional activity in glucose repression, oleate induction, and stationary phase induction follow different molecular mechanisms. We suggest that this multiplicity of regulatory mechanisms may represent a general rule for the yeast peroxisomal protein genes.