Structural, magnetic and electronic properties of pulsed-laser-deposition grown SrFeO3-δ thin films and SrFeO3-δ /La2/3Ca1/3MnO3 multilayers.

We studied the structural, magnetic and electronic properties of [Formula: see text] (SFO) thin films and [Formula: see text]/[Formula: see text] [Formula: see text]MnO3 (LCMO) superlattices that have been grown with pulsed laser deposition (PLD) on [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] (LSAT) substrates. X-ray reflectometry and scanning transmission electron microscopy (STEM) confirm the high structural quality of the films and flat and atomically sharp interfaces of the superlattices. The STEM data also reveal a difference in the interfacial layer stacking with a SrO layer at the LCMO/SFO and a LaO layer at the SFO/LCMO interfaces along the PLD growth direction. The x-ray diffraction (XRD) data suggest that the as grown SFO films and SFO/LCMO superlattices have an oxygen-deficient [Formula: see text] structure with I4/ mmm space group symmetry ([Formula: see text]). Subsequent ozone annealed SFO films are consistent with an almost oxygen stoichiometric structure ([Formula: see text]). The electronic and magnetic properties of these SFO films are similar to the ones of corresponding single crystals. In particular, the as grown [Formula: see text] films are insulating whereas the ozone annealed films are metallic. The magneto-resistance effects of the as grown SFO films have a similar magnitude as in the single crystals, but extend over a much wider temperature range. Last but not least, for the SFO/LCMO superlattices we observe a rather large exchange bias effect that varies as a function of the cooling field.

Strain-induced ferromagnetism in antiferromagnetic LuMnO3 thin films.

Single phase and strained LuMnO(3) thin films are discovered to display coexisting ferromagnetic and antiferromagnetic orders. A large moment ferromagnetism (≈1µ(B)), which is absent in bulk samples, is shown to display a magnetic moment distribution that is peaked at the highly strained substrate-film interface. We further show that the strain-induced ferromagnetism and the antiferromagnetic order are coupled via an exchange field, therefore demonstrating strained rare-earth manganite thin films as promising candidate systems for new multifunctional devices.

Characterization of a spent Ru/C catalyst after gasification of biomass in supercritical water.

Carbon-supported ruthenium catalysts promote the gasification of aqueous organic feed with high efficiency to synthetic natural gas in supercritical water. Ruthenium metal was recently identified as the catalytically active species. [1] Occasionally deactivation is observed. To understand the deactivation, the fresh and several spent catalyst samples were investigated by RBS, ERDA, and XPS. The data revealed a massive reduction of the ruthenium concentration in toto and especially of the surface concentration. Of importance is the almost complete disappearance of the spectral features in the valance band region. Coverage of the ruthenium clusters e.g. with a thin 'carbonaceous' layer, i.e. a kind of fouling, or structural modifications of the ruthenium clusters might be the origin. Additionally, leaching of ruthenium might contribute, but is not considered a major effect, because ruthenium was never found in the liquid effluent of the reactor. The influence of additionally detected corrosion products (Ni, Cr, Fe, Ti) from the stainless steel and the titanium alloy walls seems to be small. No evidence for a deactivation by sulphur could be found.

Comprehensive comparison of various techniques for the analysis of elemental distributions in thin films.

The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 µm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limits.

Characterization of oxide films by MeV ion beam techniques.

MeV ion beam techniques can provide highly quantitative compositional analysis of surfaces and thin layers. This quantitativeness is due to the very well known elastic nuclear scattering cross-sections of MeV particles. The most commonly used techniques are Rutherford backscattering spectrometry and elastic recoil detection analysis. Owing to the energy loss of ions in the material, whole compositional depth profiles can be obtained in a single short measurement almost nondestructively. The sensitivity to oxygen can be enhanced by the use of nuclear resonances or forward scattering techniques. State-of-the-art ion beam analysis can determine thin film stoichiometries with an accuracy of 1% and a depth resolution in the low nm range. An overview of the available techniques is given and illustrated with examples.

Abortifacient and endocrine effects of metergoline in beagle bitches during the second half of gestation.

The purpose of this study was to investigate the abortifacient effects of high doses of metergoline when administered to pregnant beagle bitches during the second half of gestation and to define the endocrine effects of this treatment as represented by plasma progesterone and estradiol concentrations. Previously, metergoline had been shown to be incompletely luteolytic and induced abortion in only one of eight pregnant bitches when 0.4-0.5 mg/kg were administered twice daily for 5 days from Days 18 to 20 of diestrus. Nine pregnancies in six beagle bitches were used for the present study. Three bitches were treated in each of two consecutive pregnant cycles. Metergoline was administered at a dose of 0.6 mg/kg per os twice daily, starting on Day 28 after the cytological onset of diestrus. Abortion was induced in eight of the nine treated pregnancies and started after 3-23 days of treatment (mean 12.5 days, S.D. 6.4 days). The abortions were completed within 0.5-8 days (mean 2.2 days, S.D. 2.7 days). There were no side effects associated with metergoline treatment and none of the abortions was associated with complications that required intervention. In the single bitch that did not abort, an ovarian granulosa cell tumor was discovered when the single fetus had to be removed surgically at term. Plasma progesterone concentrations declined after the start of metergoline administration in all pregnancies but levels below 4.8 nmol/l were required for successful abortions. Plasma estradiol concentrations showed a tendency to decline and fluctuate concurrently with the plasma progesterone levels. However, suppression of plasma estradiol concentrations by metergoline was not as complete as the suppression of progesterone and did not seem a prerequisite for abortion. The hormone profiles and treatment period required for abortion tended to be similar for both cycles of the three bitches that were treated during two consecutive pregnancies. This suggests a bitch effect on the factors that determine the efficacy of metergoline to induce abortion. The large variation and length of the treatment period that was required until abortion commenced was probably related to the relatively early start of treatment compared to other studies. The results of this investigation suggest that, similar to other prolactin suppressing ergot derivatives, metergoline causes complete luteolysis and can be used to reliably induce abortion only during the last 3 weeks of gestation.

Effects of EDTA-induced hypocalcaemia and stress on plasma TNF-alpha, IL-1-ra, G-CSF, GM-CSF and S-100 in dairy cows.

The pathophysiology of postparturient paresis is still not completely understood. Knowledge recently acquired in immunology, endocrinology and cell physiology has still to be integrated in order to elucidate the aetiopathogenesis of the disease. For that purpose, the effect of the EDTA infusion model on the plasma concentrations of selected cytokines and growth factors, and of a calcium binding protein was examined in dairy cows. Six 6- to 11-year-old Brown Swiss cows in mid lactation were infused with a 5% solution of Na2EDTA in one jugular vein over a period of 5 h. Blood samples were collected from the contralateral side daily two days before, and then hourly for five hours during the infusion, hourly for five hours after the end of the infusion, and once daily for 10 days thereafter. The plasma concentrations of cortisol, tumour necrosis factor-alpha, interleukin-1 receptor antagonist, granulocyte colony-stimulating factor, granulocyte and macrophage colony-stimulating factor, and the calcium binding protein S-100 were determined. Before the EDTA infusion, during the infusion and for two days thereafter, the mean plasma concentrations of cortisol were significantly higher than those from days 4 to 10 after the infusion. The plasma concentrations of tumour necrosis factor-alpha and interleukin-1 receptor antagonist followed a similar profile. At the end of EDTA infusion, low concentrations of granulocyte colony-stimulating factor were detected in one cow only. On days 3 and 4, the mean plasma concentrations of granulocyte colony-stimulating factor were significantly higher than the pre-infusion values, but this was followed by a significant decrease on post-infusion day 5. From day 4 to 7, the plasma concentrations of S-100 were significantly lower than the pre-infusion values. The importance of these findings in the pathophysiology of postparturient paresis remains to be established.

Evidence from urinary cortisol that maternal behavior is related to stress in gorillas.

By studying western lowland gorillas (Gorilla gorilla gorilla, n = 8) in zoological gardens via ethological and non-invasive physiological techniques, we have demonstrated that their postpartum maternal behavior is related negatively to their postpartum urinary titers of cortisol. On the basis of this finding, it is proposed that postpartum stress contributes to disrupted maternal behavior in the gorilla in captivity. Morning urine samples were collected with a mean sampling interval of 1.6 days from Day 14 prepartum to Day 14 postpartum (n = 11 pregnancies). Creatinine-indexed (Cr) urinary cortisol titers declined significantly between Day 9 to 1 prepartum (0.634 +/- 0.014 microg/mg of Cr, mean +/- SEM) and Day 1 to 6 postpartum (0.396 +/- 0.030 microg/mg of Cr, mean +/- SEM; p < 0.01-0.001). For each pregnancy, the relative postpartum decline in urinary cortisol was calculated as (microg of cortisol/mg of Cr Day 1 to 4)/(microg of cortisol/mg of Cr Day -4 to -1). Values ranged from 0.35 to 1.12, were independent of absolute prepartum cortisol titers, and were interpreted as evidence of inter-female differences in postpartum hypothalamo-pituitary-adrenal axis activity and, therefore, postpartum stress. This postpartum stress index was negatively correlated with the amount of time (0-100%) that females carried and supported their 0-14 day-old infants in a ventral position during locomotion (r(s) = -0.68, p < 0.05) and tended to be negatively correlated with the total amount of time (0-100%) they spent in ventro-ventral contact with their infants (r(s) = -0.58; p < 0.10). This study provides the first physiological evidence that postpartum stress is an important etiologic factor in gorilla maternal failure in captive environments.

Physiological Responses to parental separation and a strange situation are related to parental care received in juvenile Goeldi's monkeys (Callimico goeldii).

The relationship between parental care received and physiological and behavioral responses to parental separation, isolation, and reunion was investigated in seven juvenile Goeldi's monkey living in their family groups. Physiological responses were measured non-invasively: the hypothalamic-pituitary-adrenal axis via urinary cortisol output and the autonomic nervous system via piloerection on the tail. Parent-infant aggression demonstrated high intergroup variation and predicted: (a) an increase in urinary cortisol output, r(s) = 0.86, p = 0.04, and duration of piloerection, r(s) = 0.71, p = 0.08, at initial separation-isolation; (b) adaptation of piloerection, r(s) = -0.89, p = 0.03, to repeated separation-isolation. Juvenile Goeldi's monkeys that had received high parental aggression were more physiologically responsive to separation; they also sought more contact with their mothers at reunion, rs = 0.93, p = 0.02. We propose that these data are consistent with the hypothesis that high emotional reactivity is related to insecure attachment to aggressive parents in this New world primate.

Exposure of Allan Hills 84001 and other achondrites on the Antarctic ice.

The enrichment of F on Antarctic meteorites is the result of their exposure to the atmosphere, and its measurement allows a subdivision of the terrestrial age into a duration of exposure on the ice and the time a meteorite was enclosed by the ice. In many cases, the periods of surface exposure are only small fractions of the terrestrial ages of meteorites collected in Antarctica. The enrichment of F on the surfaces of Antarctic achondrites was investigated by means of nuclear reaction analysis (NRA): scanning proton beams with an energy of 2.7 and 3.4 MeV were used to induce the reactions 19F(p, alpha gamma)16O and 19F(p,p gamma)19F, respectively. Gamma signals proportional to the F content were measured. The following Antarctic achondrites were investigated: Martian meteorite ALH 84001; diogenite ALHA77256; the eucrites ALHA81011 and ALHA78132; and in addition, the H5 chondrite ALHA79025. For ALH 84001, our data indicate a period of exposure on the ice of <500 years. Thus, this specimen was enclosed in the ice >95% of its terrestrial age of 13 000 years.

[Endocrinologic and pathologic findings in ornamental birds with polyostotic hyperostosis]. / Endokrinologische und pathologische Befunde bei Ziervögeln mit polyostotischer Hyperostose.

Polyostotic hyperostosis is a finding that is often seen on x-rays in companion birds. Hyperestrogenism might be a causative for polyostotic hyperostosis. The purpose of this study was to compare endocrinologic and pathologic findings in birds with polyostotic hyperostosis. Thirty-five affected and three control birds were examined. Blood samples were taken for endocrinologic statement (estrone, estradiol, testosterone and estrone sulfate) and the values were compared with the pathologic findings. In the present study the comparison of endocrinologic and pathologic findings did not reveal any significant results supporting the hypothesis that polyostotic hyperostosis was caused by hyperestrogenism.

An investigation into sexual motivation and behavior in female Goeldi's monkey (Callimico goeldii): effect of ovarian state, mate familiarity and mate choice.

Four adult female Callimico were studied in terms of their sexual motivation relative to three unrelated adult males using an operant paradigm followed by a pair test or a two-male choice test. Reductions in urinary cortisol concentrations and the duration of immobility were used as indicators of subjects' adjustment to the experimental situation. When females were tested with unfamiliar males there was no effect of ovarian state on operant or species-typical measures of female sexual motivation. When females were retested with the same males after a 1-week familiarization, sexual motivation was higher during the peri-ovulatory phase than during the post-ovulatory phase in terms of operant but not in terms of species-typical proceptive behavior or in terms of receptive behavior. During the familiarization periods, female sociopositive behavior and sexual motivation demonstrated marked variation depending on the identity of the male. Males with which females demonstrated high sexual motivation during familiarization were the object of equal amounts of female operant behavior during pair tests and two-male choice tests; males with which females had demonstrated low sexual motivation were the objects of less female sexual motivation under conditions of female choice than in pair tests.

Comparative study of oestrogen excretion in female New World Monkeys: an overview of non-invasive ovarian monitoring and a new application in evolutionary biology.

Oestrogen was measured in urine samples collected from captive females representing 7 species of New World monkey to provide an overview of the applicability of such formation in the noninvasive monitoring of ovarian function and to assess the potential applicability of such information in phylogenetic studies. Species available for study were the pygmy marmoset, common marmoset, red-bellied tamarin, cotton-top tamarin, golden lion tamarin, Goeldi's monkey and the owl monkey. Oestrone conjugates were measured in serially collected urine samples to demonstrate ovarian cyclicity. Urine samples obtained during the luteal phase were subjected to HPLC to identify immunoreactive oestrogens; oestrone and oestradiol-17 beta accounted for almost all of the immunoreactive oestrogen detected while oestriol content was negligible. Urine samples obtained during the follicular phase and luteal phase were subjected to glucuronidase hydrolysis, sulphatase hydrolysis and acid solvolysis, which revealed that the major immunoreactive oestrogen metabolite was: (1) oestradiol sulphate in the pygmy marmoset and common marmoset, (2) residual oestradiol in the red-bellied tamarin, (3) residual oestradiol and oestrone glucuronide in the cotton-top tamarin, and (4) oestrone glucuronide in the golden lion tamarin, Goeldi's monkey and owl monkey. A phylogenetic tree based on the above shifts in oestrogen excretion suggested that clawed New World monkeys are specialized and that the lineages leading to the study species split off in the following order: Goeldi's monkey, golden lion tamarin, cotton-top tamarin, red-bellied tamarin, common marmoset and pygmy marmoset.

Non-invasive detection and monitoring of pregnancy and the postpartum period in goeldi's monkey (Callimico goeldii) using urinary pregnanediol-3α-glucuronide.

Pregnanediol-3α-glucuronide (PdG) was measured in the urine of six Goeldi's monkeys during pregnancy and the postpartum period. A stress-free, non-invasive urine sampling technique permitted frequent collection of urine from members of the breeding group. A comparison of the periovulatory profiles of PdG and estrone conjugates revealed close agreement. The day of ovulation was defined as that immediately preceding a 2-4 day period with two consecutive urine samples for which the PdG content was in excess of 0.20 µg/mg Cr and 0.40 µg/mg Cr, respectively. In urine samples collected from parturition to the next ovulation, 70.9% of the PdG-values were below 0.20 µg/mg Cr, whereas 99.2% of the urinary PdG concentrations measured during pregnancy were greater than this "threshold concentration". A conception cycle was therefore defined as one in which the concentration of urinary PdG remained above 0.20 µg/mg Cr in all urine samples collected between day 1 and day 20 after ovulation. Gestation length was 151.5 ± 1.6 days (mean ± SEM, n = 6; range 147-157 days). The postpartum ovulation occurred 22.6 ± 4.7 days (mean ± SEM, n = 9; range 11-53 days) following birth. With the exception of two non-conception postpartum cycles observed in one female, with inter-ovulatory intervals of 26 and 27 days, postpartum ovulation resulted in conception, giving a 77.8% conception rate for nine observed cycles. The simple and rapid radioimmunoassay used in this study requires 5 h from urine collection to the final result, hence permitting daily monitoring of a large sample of females. It thus has important potential for conservation breeding programs and for other scientific investigations carried out with this endangered primate species. © 1994 Wiley-Liss, Inc.

Effects of sex steroids on maternal motivation in the common marmoset (Callithrix jacchus): development and application of an operant system with maternal reinforcement.

We developed an operant paradigm for measuring effects of reproductive steroids on maternal motivation in common marmosets (Callithrix jacchus). Conditioned response regulated females' exposure to maternal reinforcement. Nulliparous females (n = 15) with experience with infants in social groups were subjects. The paradigm was validated by examining (a) effects of reinforcing stimuli on affective behavior in a nonoperant paradigm, (b) responsiveness of operant performance to changes in reinforcing stimuli and reinforcement schedule, (c) changes in operant responding due to omission of reinforcement, and (d) relation between operant responding and species-typical maternal behavior. In pregnant females, (n = 4), frequency of bar pressing and estradiol:progesterone ratio were maximal just before birth. Nonpregnant females (n = 3) treated with progesterone and estradiol to mimic late-pregnancy steroid profiles showed increased operant maternal behavior.

[Estradiol and progesterone concentrations in the plasma of nonpregnant bitches during the sexual cycle]. / Ostradiol- und Progesteronkonzentrationen im Plasma von nicht trächtigen Hündinnen während des Sexualzyklus.

Measurement of the plasma concentrations of oestradiol and progesterone in six bitches on 180 consecutive days showed large fluctuations in the levels of both hormones. The concentrations of oestradiol began to increase 10-12 days before the peak levels of 38.1-89.7 pg/ml were reached, then declined again over the next 3-7 days to or below the minimum measurable value of 9 pg/ml. On the day after the maximum concentrations of oestradiol were recorded, plasma progesterone began to rise rapidly, reaching a plateau after approximately two weeks, then declining gradually after a further two weeks. At the height of the luteal phase, peak levels of 12.6-70.1 ng/ml were measured, although on some days values of less than 1 ng/ml were recorded. The time of occurrence of the initial rise in the progesterone concentration during oestrus presumably indicates that preovulatory luteinization had taken place. During anoestrus the basal concentration of progesterone was generally less than 1 ng/ml and that of oestradiol less than 9 pg/ml. The normal values derived from these observations are discussed with regard to the interpretation of oestradiol and progesterone concentrations in domestic pets under treatment in veterinary practice.

[Estrus induction in bitches by the administration of PMSG and HCG]. / Brunstinduktion bei Hündinnen durch Verabreichung von PMSG und HCG.

Oestrus was induced in 14 anoestrous beagle bitches by intramuscular injection of PMSG in a dose of 20 I.U./kg once daily on five consecutive days, followed by an additional single i.m. injection of 500 I.U. of hCG on the fifth day. The day on which the first injection was given was counted as Day 1 of the experiment. Between the fourth and sixth day, the bitches began to attract the attention of male dogs and between Days 9 and 15 all bitches came in heat. Matings occurred on two to ten occasions, and six of the bitches conceived. The maximum concentrations of oestradiol in the plasma were in most cases reached on Days 10 or 12 and ranged from 42 to 195 pg/ml. In all cases progesterone concentrations rose sharply between Days 10 and 20. The incretion phase of the corpora lutea was noticeably brief in the non-gravid bitches; in five of these eight bitches, anoestrous values below 2 ng/ml were already obtained before the 65th day of the experiment. These results indicate that the administration of PMSG on five consecutive days supplemented by a final single injection of hCG stimulates the ovaries adequately to afford good prospects of conception. The concentrations of ovarian hormones are discussed.

[The effect of HCG-progesterone combination therapy in cows with ovarian cysts]. / Die Wirkung der HCG-Progesteron-Kombinationstherapie bei Kühen mit Ovarialzysten.

Eighty-one cows with ovarian cysts were treated with one group receiving 1500 IU HCG/150 mg progesterone and the other group receiving 5000 IU HCG/300 mg progesterone. A second examination was performed two weeks later. Milk progesterone levels were determined both initially and at the follow-up examination. No significant relationships were observed between firmness of the wall of the cysts as well as other clinical signs and the progesterone values. The examination two weeks later revealed similar findings for both treatments with a great variability within the groups. Normal ovarian activity was observed in slightly more than half of the animals. The discussion of the findings also considers the high tendency of ovarian cysts for spontaneous regression.

[The asymmetric distribution of ovarian functional structures in cattle]. / Untersuchungen über die asymmetrische Verteilung ovarieller Funktionsgebilde beim Rind.

The results of continually repeated transrectal palpations, performed in 168 post partum periods, 383 estrous cycles and 178 early pregnancies, were used to describe and to discuss the left-right distribution of ovarian functional structures. In cycling as well as in pregnant cattle, anovulatory interestral follicles and estrous follicles or corpora lutea in the mean were all distributed at 41% and 59% on the left and right ovaries respectively. No signs were found indicating that the position of functional structures would be influenced by local interactions between follicles and corpora lutea. At least for cyclic ovarian activity, and in early pregnancy, the interrelationship observed between the locations of these structures could be put down to the normally increased activity of the right ovary. After delivery, the first follicles preferentially became discernible on the ovary opposite to the previously pregnant uterine horn. But, as from the 4th follicle p.p. onward, the distribution of new ovarian structures again agreed with the one of the ensuing reproductive stages. After calving, probably the position of new follicles is temporally influenced by direct signals from the uterine horns affected differently by pregnancy. Several observations indicate that the factors causing asymmetrical ovarian activity could exert a selective effect on the recruitment of the dominant and solitary interestral follicles from the pool of their minor and less differentiated precursors.