Search

Recent animal and human studies highlight the uncertainty about the onset of an aversive event as a crucial factor for the involvement of the centromedial amygdala (CM) and bed nucleus of the stria terminalis (BNST) activity. However, studies investigating temporally predictable or unpredictable threat anticipation and confrontation processes are rare. Furthermore, the few existing fMRI studies analyzing temporally predictable and unpredictable threat processes used small sample sizes or limited fMRI paradigms. Therefore, we measured functional brain activity in 109 predominantly female healthy participants during a temporally predictable-unpredictable threat paradigm, which aimed to solve limited aspects of recent studies. Results showed higher BNST activity compared to the CM during the cue indicating that the upcoming confrontation is aversive relative to the cue indicating an upcoming neutral confrontation. Both the CM and BNST showed higher activity during the confrontation with unpredictable and aversive stimuli, but the reaction to aversive confrontation relative to neutral confrontation was stronger in the CM compared to the BNST. Additional modulation analyses by NPSR1 rs324981 genotype revealed higher BNST activity relative to the CM in unpredictable anticipation relative to predictable anticipation in T-carriers compared to AA carriers. Our results indicate that during the confrontation with aversive or neutral stimuli, temporal unpredictability modulates CM and BNST activity. Further, there is a differential activity concerning threat processing, as BNST is more involved when focussing on fear-related anticipation processes and CM is more involved when focussing on threat confrontation.

This study measured the wake effect in a Brazilian onshore windfarm with 38 turbines located in complex terrain. The proposed methodology calculated the wind deficit in 3 different metmasts, by comparing the measurement periods in free-of-wake condition to measurement periods under wake effect. Uncertainties due to wind variability and seasonality effects have been avoided by performing MCP (Measure Correlate Predict) procedures making use of a fourth metmast in free-of-wake condition during the entire concurrent period. This methodology is free of uncertainties from Nacelle anemometry, power curve measurements and micrositing models' spatial extrapolation. The calculation of the wind deficits was performed per sector, confirming the adherence of the resulting wake effect to the turbine layout configuration. Higher wind deficits were identified in the sectors were turbines under operation are present in the upwind direction. The results were combined to the power curves from the turbines closest to the metmasts, using the data from the turbine supplier's technical specification. This allowed the identification of the respective power deficit due to the wake effect in these locations. The calculated wind- and power deficits were compared to the results of wake models used by two large international wind farms site assessment consultants (Coupled Eddy Viscosity and PARK), commonly accepted by banks for the financing of wind farms in Brazil. The results indicated that both models underestimate the effects in all 3 analyzed locations, with differences between the calculated and modeled power deficits higher than the respective uncertainties provided by both consultants. The two main limitations of this analysis lie in the restriction of the wake effect measurement to the metmasts locations, and in that the results are respective to the terrain conditions of the analyzed wind farm. However, this study indicates that commonly used wake models need to be further developed and calibrated for onshore wind farms. The literature shows that wake models developments are frequently directed to offshore wind farms, where wake effects play a significant role. Onshore wind farms are less studied, even though the global installed capacity greatly surpasses that of the offshore wind farms. Brazil has by the end of 2017 already 12.8 GW of installed capacity of wind power plants, and this number continues to increase steadily. With the continuous concentration of operating wind farms in regions of higher wind resource and transmission infrastructure, wake effects play a significant role in the sector. Bibliography shows that commonly used wake models tend to underestimate the energy losses due to this effect in offshore wind farms, making it important to study it also in onshore wind farms in complex terrain, which is the case of most Brazilian wind farms.

The profitability of a wind power project is evaluated during its development phase through a complete site assessment. At this stage, the LCoE (Levelized Cost of Energy) is determined considering many variables, such as wind turbine model, project layout, energy production, CAPEX (Capital Expenditure), OPEX (Operational Expenditure) and financial costs. However, in recent years, the seasonality and variability of the wind farms energy production have been gaining importance in this process in some markets, due to a migration of the new wind power projects from the regulated market to the free market. In the free market, the PPAs (Power Purchase Agreements) have short-term balance payments, different from the regulated market. In Brazil, payments in the regulated market are performed monthly based on the long-term AEP (Annual Energy Production) expected values, with annual and quadrennial balance payments. This paper focuses on an extensive case study of Brazil, where the energy spot prices vary constantly between 10 USD/MWh and 100 USD/MWh, exposing the wind farms owners to very relevant financial risk when trading energy based on long-term bilateral contracts. The assumed risks can become critical in cases of periods with extreme meteorological anomalies (wind speed variations below the respective long-term expected values), especially in situations where a simultaneous drought period occurs, eventually raising the market spot price to its ceiling value. A SPE (Specific Purpose Entity) account must be properly dimensioned and maintained, similar to a working capital, in order to the wind farm to be able to operate through these low wind speed periods without any capital call to the wind farm’s controllers. This represents additional financial costs in the form of trapped cash. This study analyses the wind speed variability in NE-Brazil, where most of the wind farms in the country are concentrated, and analyses how the portfolio effect contributes to the reduction of this variability. This has been performed making use of the data provided by 4 met masts that surround the NE Brazilian territory (with distances between them ranging from 459 km to 724 km) and combining the obtained values to theoretical turbine power curves of different MW platforms (2, 3, 4 and 6 MW). The total period of available measurement sums more than 29 years of data. The results showed that the variability was higher in periods of lower average wind speed and that the analyzed location with the highest variability was the one close to the coast and with higher altitude. Additionally, the combinations that provided the best portfolio effect were those that included the location in the SW, furthest from the coast and with higher altitude. The different turbine platforms did not present a relevant difference in terms of resulting variability on the energy production nor portfolio effect, but when considering the cumulative impact of the meteorological anomalies (larger periods of wind speeds above or below the long-term expected values), the larger the wind turbine, the larger was the resulting exposure.

Objective: Electrical impedance tomography (EIT) is a non-invasive and relatively cheap imaging technique allowing continuous monitoring of lung function at the bedside. However, image reconstruction and processing are not yet standardized for clinical use, limiting comparability and reproducibility between studies. In addition, optimal reconstruction settings still have to be identified for different clinical applications. In this work (i) a systematic way to select ‘good’ EIT algorithm parameters is developed and (ii) an evaluation of these parameters in terms of correct functional imaging and consistency is performed. Approach: First, 19 200 reconstruction models are generated by full factorial design of experiment in 5D space. Then, in order to quantify the quality of reconstruction, known conductivity changes are introduced and figures of merit (FoM) are calculated from the response image. These measures are further used to select a subset of reconstruction models, matching certain FoM thresholds, and are then used for in vivo evaluation. For this purpose, EIT images of one piglet are reconstructed to assess changes in tidal impedance and end-expiratory lung impedance, at positive end expiratory pressure of 0 and 15 cmH2O. From ground truth spirometry measurements, physiological criteria are formulated and the subset of models is further reduced. Finally, the remaining reconstruction models are evaluated on physiological data gathered from published data in the literature to assess the generalization possibilities. Main results: Parametrization of EIT image reconstruction has a strong influence on the resulting FoM and the derived physiological parameter. While numerous reconstruction models showed reasonable values for a single parameter, in total only 12 matched all simulation and physiological criteria. After validation on further physiological data, only a single reconstruction model remained with a noise figure of 0.3, target size of 0.08, weight radius of 0.3, normalized voltage and strong weighting of lung and heart regions. Furthermore, the relationship between the reconstruction settings and some FoM could be partly explained by using a linear statistical model. Significance: The quest for standard reconstruction settings is highly relevant for future clinical applications. Simulation measures might help to assess the quality of the reconstruction models, but further evaluation of more data and different experimental settings is required.

Micrositing wind flow modeling presents one of the most relevant uncertainties in the project of wind power plants. Studies in the area indicate that the average uncertainty related to this item varies between 2.4% and 8% of the annual energy production (AEP). The most efficient form to mitigate this uncertainty is to obtain additional measurements from the site. This can be achieved by installing met masts and by applying short-term remote sensing campaigns (LIDAR and SODAR). Ideally, measurement campaigns should have at least one complete year of data to capture seasonal changes in the local wind behavior and to increase the long-term representation of the sample. However, remote sensing is frequently performed in reduced periods of measurement, coming down to months or even weeks of campaign. The main contribution of this paper is to analyze whether short-term remote sensing measurements contribute to the development of wind power projects, given the associated uncertainties due to low representativeness of the reduced data sample. This study was performed using over 60 years of wind measurement data. Its main findings indicate that the contribution of short-term remote sensing campaigns vary depending on the complexity of the local terrain, and the respective uncertainty related to horizontal and vertical extrapolation of micrositing models. The results showed that in only 30% of the cases, a 3 month measurement campaign reduced the projects overall uncertainty. This number increases to 50% for a 6 month campaign and 90% for a 10 month campaign.

The Gravity Recovery and Climate Experiment (GRACE) is a successful Earth observation mission launched in 2002 and consisting of two identical satellites in a polar low-Earth orbit.

The Gravity Recovery and Climate Experiment Follow-On (GRACE FO) is a space borne mission to map variations in the earth’s gravity field with an even greater accuracy than the first GRACE mission. GRACE FO is a collaborative project of NASA (USA) and GFZ (Germany) scheduled for launch in 2017. On GRACE the gravity field is reconstructed from a measurement of the distance variation between two satellites following each other in 200 km distance by use of a microwave ranging instrument. On GRACE FO a laser ranging interferometer (LRI) is added as a demonstrator in addition to the microwave. Moving from microwave range to optical wavelengths provides an improvement in distance measurement noise from some μm/√Hz to 80 nm/√Hz down to 0.01 Hz frequency. The criteria on the beam delivery system are demanding, in particular with respect to laser beam quality, wave front deviation and pointing as well as thermal and mechanical stability. Conventionally such a system can be manufactured with at least two special mounted lenses or an aspheric lens aligned with respect to the fiber end. However, the alignment of this optical system must be maintained throughout the mission, including the critical launch phase and a wide temperature range in orbit, leading to high alignment effort and athermal design requirements. The monolithic fiber-collimator presented here provides excellent optical and thermal and mechanical performance. It is a part of the LRI and located on the Optical Bench Assembly (OBA) which has already been described in [1, 3].

Background The purpose of this retrospective cohort study was to evaluate, compare and discuss the results and complications after primary and secondary shoulder arthoplasty in proximal humeral fractures. Patients and methods Thirteen consecutive patients (mean 76 years [range, 65-85] years) were at a mean of 29 (8-37) months after primary humeral head replacement (group 1), and 15 patients (mean 74 years [range, 43-80] years) at a mean of 18 (7-36) months after secondary shoulder arthoplasty (n = 8 anatomic prostheses, n = 7 reversed prostheses) due to complications/fracture sequelae (group 2) examined clinically and radiologically according to a standardised follow-up protocol. Patient satisfaction, the simple shoulder test (SST), the American shoulder elbow score (ASES) as well as the Constant score (CS) were assessed, and radiological parameters as well as complications analysed. Results 85 % of patients in group 1 and 73 % in group 2 were satisfied with the results. The SST did not show a significant difference between both groups. The adjusted ASES did not differ significantly with 70 (27-95)% in group 1 and 73 (28-100)% in group 2, as well as the adjusted CS with a mean of 53 (27-83)% in group 1 and of 49 (27-87)% in group 2. Radiological analysis resulted in a correctly centred prosthesis in 6/13 patients, and healed tuberosities in 7/13 of group 1. In group 2 4/8 anatomic prostheses were centered and 7/8 showed healed tuberosities. In the subgroup of the reversed prostheses 6/7 were centered, 3/7 patients had an inferior "notching". The rate of complications and revisions were 2/13 (15 %) in group 1 and 1/15 (7 %) in group 2. Conclusion In summary, the functional results did not differ significantly between primary and secondary shoulder arthroplasty after proximal humeral fractures. The relatively low expectation of elderly patients is reflected in a high rate of patient satisfaction in spite of moderate functional results. The primary humeral head replacement showed higher rates of complications and revisions compared to secondary arthroplasty.

Purpose: This is an analysis of high-resolution computed tomography (HR-CT) performed in patients with and without symptoms after stapes surgery during the early postoperative phase. Materials and Methods: We examined 37 patients who underwent stapes surgery between January 1995 and December 2000. HR-CT of the temporal bone was performed in axial and coronal planes with 1-mm-slice thickness and table feed. A reoperation was performed in 7 patients. CT findings were compared with clinical follow up and surgical findings. Results: All patients showed postoperative opacification of the tympanic cavity and external auditory canal as well as partial opacification of the mastoid on CT scans. A dislocation of the prosthesis was found in 11 cases and air bubbles were seen in the vestibule of 5 patients. In one case, small bone fragments were detected in the vestibule. In 6 of 7 cases, CT results were confirmed by retympanotomy. Conclusions: Due to overlapping of normal and pathological findings in the early postoperative period, indications for HR-CT are limited in this period.

Whether leukotriene receptor antagonists exhibit adequate anti-inflammatory effects in the treatment of asthma is still a controversial issue. The aim of the present study was to perform a direct comparison of the effects of a 4-week treatment with either montelukast (10 mg, once a day) or low-dose inhaled fluticasone (100 microg b.i.d.) on functional and inflammatory parameters in steroid-naïve patients with moderate asthma. Forty patients (forced expiratory volume in one second (FEV1), 60-80% predicted) were studied in a double-blind, randomised, crossover design. Treatment periods were separated by 3-8 weeks of washout. At the beginning and end of each period, FEV1, airway responsiveness to inhaled methacholine (provocative concentration causing a 20% fall in FEV1 (PC20)), the level of exhaled nitric oxide (NO) and sputum differential cell counts were determined. Only short-acting beta2-agonists were allowed for relief of symptoms. FEV1 increased by 0.50+/-0.07 L (mean+/-SEM) after fluticasone and by 0.37+/-0.07 L after montelukast (p0.001, each), and PC20 by 1.33+/-0.13 (p0.001) and 0.15+/-0.17 (NS) doubling doses, respectively. Correspondingly, percentages of sputum eosinophils were reduced by factor 2.7 (p0.01) and 1.4 (nonsignificant (NS)), and the levels of exhaled NO (at 50 mL x s(-1)) by factor 2.1 (p0.01) and 1.1 (NS). These data indicate a comparable bronchodilator action of montelukast and fluticasone in patients with moderate asthma, but additional attenuation of airway inflammation by fluticasone as detectable through noninvasive methods.

Summary Background Single exposures to > 200 p.p.b. of ozone are capable of enhancing the early-phase lung function response to allergen. Objective The aim of the present study was to compare the effect of single vs. repeated exposures to ozone on early and late-phase allergen responses. Methods Eleven subjects with allergic asthma and 22 subjects with allergic rhinitis underwent single exposures to filtered air, 125 p.p.b. and 250 p.p.b. ozone, as well as repeated exposures to 125 p.p.b. ozone on four consecutive days. Twenty hours after the (final) exposure, subjects inhaled a single dose of allergen and a sputum induction was performed 6–7 h later. Results In the subjects with rhinitis, the mean early-phase response of FEV1 and the number of ≥ 20% reductions were significantly greater after exposure to 250 or 4 × 125 p.p.b. ozone compared with filtered air. In addition, most of the ≥ 15% late-phase responses in FEV1 occurred after exposure to 4 × 125 p.p.b., as well as the strongest effects on sputum parameters. The rise in the number of eosinophils was statistically significant in both groups. Regarding the number of lymphocytes and the concentrations of mast cell tryptase, histamine or LDH, significance was, however, only reached in the asthma group. Conclusion Our data suggest that repeated exposure to ozone, at a peak ambient air level, can enhance both functional and inflammatory responses to inhaled allergen in subjects with pre-existing allergic airway diseases, and that these effects might reach a clinically relevant magnitude.

To assess the efficacy of ciclesonide, a novel corticosteroid pro-drug, we compared its effect on lung function, airway responsiveness to inhaled AMP, the composition of induced sputum, and the level of exhaled nitric oxide (NO) with the effect of budesonide in patients with asthma. Fifteen non-smoking steroid-naive patients (mean FEV(1), 94%pred) inhaled either 400 microg ciclesonide or 400 microg budesonide as a single morning dose for two weeks each separated by a > or =3 week wash-out period. The study was performed in a double-observer, randomized, cross-over design. FEV(1)increased significantly during treatment with budesonide (3.38 vs. 3.64 l P=0,003), but not after ciclesonide (3.60 vs. 3.69 l). PC(20)FEV(1)of AMP increased (P

Die Autokovarianzfunktion der Differenzen in Lange zwischen Clemence' Theorie des Mars und der numerischen Integration von Herget zeigt, das diese Widerspruche ein trigonometrisches Glied mit einer Periode von 724d und einer mittleren Amplitude von 0ṁ015 enthalten.

Oxygen-deficient ferrates with the cubic perovskite structure SrxY1-xFeO3-d were prepared in air (0.71 ≤ x ≤ 0.91) as well as in N2 (x=0.75 and 0.79) at 1573K. The oxygen content of the compounds prepared in air increases with increasing strontium content from 3-δ=2.79(2) for x=0.75 to 3-δ=2.83(2) for x=0.91. Refinement of the crystal structure of Sr0.75Y0.25FeO2.79 using TOF neutron powder diffraction (NPD) data shows high anisotropic atomic displacement parameter (ADP) for the oxygen atom resulting from a substantial cation and anion disorder. Electron diffraction (ED) and high-resolution electron microscopy (HREM) studies of Sr0.75Y0.25FeO2.79 reveal a modulation along p with G± ~0.4p indicating a local ordering of oxygen vacancies. Magnetic susceptibility measurements at 5-390K show spin-glass behaviour with dominating antiferromagnetic coupling between the magnetic moments of Fe cations. Among the studied compositions, Sr0.75Y0.25FeO2.79 shows the lowest thermal expansion coefficient (TEC) of 10.5 ppm K-1 in air at 298-673K. At 773-1173K TEC increases up to 17.2 ppm K-1 due to substantial reduction of oxygen content. The latter also results in a dramatic decrease of the electrical conductivity in air above 673K. Partial substitution of Fe by Cr, Mn and Ni according to the formula Sr0.75Y0.25Fe1-yMyO3-δ (y=0.2, 0.33, 0.5) leads to cubic perovskites for all substituents with y=0.2. Their TECs are higher in comparison with un-doped Sr0.75Y0.25FeO2.79. Only M=Ni has increased electrical conductivity compared to un-doped Sr0.75Y0.25FeO2.79. Studies of cobalt based perovskites for cathode materials in solid oxide fuel cells.

The purpose of this retrospective cohort study was to evaluate, compare and discuss the results and complications after primary and secondary shoulder arthoplasty in proximal humeral fractures.Thirteen consecutive patients (mean 76 years [range, 65-85] years) were at a mean of 29 (8-37) months after primary humeral head replacement (group 1), and 15 patients (mean 74 years [range, 43-80] years) at a mean of 18 (7-36) months after secondary shoulder arthoplasty (n = 8 anatomic prostheses, n = 7 reversed prostheses) due to complications/fracture sequelae (group 2) examined clinically and radiologically according to a standardised follow-up protocol. Patient satisfaction, the simple shoulder test (SST), the American shoulder elbow score (ASES) as well as the Constant score (CS) were assessed, and radiological parameters as well as complications analysed.85 % of patients in group 1 and 73 % in group 2 were satisfied with the results. The SST did not show a significant difference between both groups. The adjusted ASES did not differ significantly with 70 (27-95)% in group 1 and 73 (28-100)% in group 2, as well as the adjusted CS with a mean of 53 (27-83)% in group 1 and of 49 (27-87)% in group 2. Radiological analysis resulted in a correctly centred prosthesis in 6/13 patients, and healed tuberosities in 7/13 of group 1. In group 2 4/8 anatomic prostheses were centered and 7/8 showed healed tuberosities. In the subgroup of the reversed prostheses 6/7 were centered, 3/7 patients had an inferior "notching". The rate of complications and revisions were 2/13 (15 %) in group 1 and 1/15 (7 %) in group 2.In summary, the functional results did not differ significantly between primary and secondary shoulder arthroplasty after proximal humeral fractures. The relatively low expectation of elderly patients is reflected in a high rate of patient satisfaction in spite of moderate functional results. The primary humeral head replacement showed higher rates of complications and revisions compared to secondary arthroplasty.

A new method of electric power input for plasma-processing batch scale applications is presented. The concept is based on electric power splitting and rf-transformation within the vacuum chamber. The hardware for power transformation in a low-pressure environment is realized by modular rf-plasma sources operating with a heat storage system. Parasitic glow discharges and arcs can be avoided using the suggested method.

This is an analysis of high-resolution computed tomography (HR-CT) performed in patients with and without symptoms after stapes surgery during the early postoperative phase.We examined 37 patients who underwent stapes surgery between January 1995 and December 2000. HR-CT of the temporal bone was performed in axial and coronal planes with 1-mm-slice thickness and table feed. A reoperation was performed in 7 patients. CT findings were compared with clinical follow up and surgical findings.All patients showed postoperative opacification of the tympanic cavity and external auditory canal as well as partial opacification of the mastoid on CT scans. A dislocation of the prosthesis was found in 11 cases and air bubbles were seen in the vestibule of 5 patients. In one case, small bone fragments were detected in the vestibule. In 6 of 7 cases, CT results were confirmed by retympanotomy.Due to overlapping of normal and pathological findings in the early postoperative period, indications for HR-CT are limited in this period.

This study assessed the effect of the leukotriene receptor antagonist montelukast on hypertonic saline-induced airway obstruction. A total of 29 patients with chronic obstructive pulmonary disease (forced expiratory volume in one second (FEV 1 ), 42±4% predicted) received either 10 mg montelukast and 3 h later placebo via metered-dose inhaler (MDI) (M), or placebo and 3h later 200 µg salbutamol (S), or two doses of placebo (P), in a randomised order. Patients inhaled salbutamol 1 h after MDI and the challenge was performed 15 min later (3% saline, 5 min). Data are given as per cent changes versus baseline. Compared to P, S caused significant bronchodilation in FEV 1 (7.3%) and forced inspiratory volume in one second (FIV 1 ) (4.5%), and M in FIV 1 (1.5%). The saline-induced fall in FEV 1 was lower after M (−5.8%), compared with S (−10.3%) and P (−13.1%). FEV 1 (11.3%) and FIV 1 (7.6%) was improved over baseline after recovery by M but not P and S. Recovery times regarding FEV 1 (8.5 min) and FIV 1 (15.2 min) were shortest after M, respective values for S being 16.8 and 20.4 min, and for P 15.9 and 21.2 min. Effects were strongest in patients with low baseline FEV 1 and/or inhaled corticosteroids. Data from this study indicate beneficial effects of montelukast on hypertonic saline-induced airway responses in patients with chronic obstructive pulmonary disease, particularly those with severe disease. The major effect was an accelerated recovery leading to values above baseline.

Single exposures to200 p.p.b. of ozone are capable of enhancing the early-phase lung function response to allergen.The aim of the present study was to compare the effect of single vs. repeated exposures to ozone on early and late-phase allergen responses.Eleven subjects with allergic asthma and 22 subjects with allergic rhinitis underwent single exposures to filtered air, 125 p.p.b. and 250 p.p.b. ozone, as well as repeated exposures to 125 p.p.b. ozone on four consecutive days. Twenty hours after the (final) exposure, subjects inhaled a single dose of allergen and a sputum induction was performed 6-7 h later.In the subjects with rhinitis, the mean early-phase response of FEV1 and the number ofor = 20% reductions were significantly greater after exposure to 250 or 4 x 125 p.p.b. ozone compared with filtered air. In addition, most of theor = 15% late-phase responses in FEV1 occurred after exposure to 4 x 125 p.p.b., as well as the strongest effects on sputum parameters. The rise in the number of eosinophils was statistically significant in both groups. Regarding the number of lymphocytes and the concentrations of mast cell tryptase, histamine or LDH, significance was, however, only reached in the asthma group.Our data suggest that repeated exposure to ozone, at a peak ambient air level, can enhance both functional and inflammatory responses to inhaled allergen in subjects with pre-existing allergic airway diseases, and that these effects might reach a clinically relevant magnitude.

Acidithiobacillus ferrooxidans R 1 and Desulfovibrio vulgaris NCIMB 8457 were taken as test strains in a study for the development of a chemotaxis test using a modified capillary assay. 2.0-μl glass capillaries were filled with 1.6 μl of a solution containing chemotactic substances under vacuum. Thereby a better load of the capillaries with the chemotactic substances was ensured. This enabled a highly precise, direct microscopic enumeration of cells using a THOMA chamber. Attractants were characterised by a migration of cells into glass capillaries filled with chemotactic substances and consequently high cell numbers therein. Compared to a control, a low cell number in the glass capillaries indicated that the test substance was a repellent. A.ferrooxidans was attracted by Fe 2+ ions and tetrathionate. The effect was dependent on the concentration: at a concentration of 100.0 mM Fe 2+ , 6.0 x 10 3 cells/capillary were enumerated, at a concentration of 1.0 mM Fe 2+ ,only 10 3 cells/capillary were counted. The effect of tetrathionate was not as significant as that of Fe 2+ ions: at concentrations of 1.0 and 10.0 mM tetrathionate, 1.0 x 10 3 cells per capillary and at a concentration of 100.0 mM tetrathionate, 2.0 x 10 3 cells/capillary were determined. After the application of 0.1, 1.0 and 10 mM aspartate, low cell numbers in the glass capillaries were found. Consequently, aspartate acted as a repellent. Cells of D. vulgaris were attracted by lactate and thiosulphate. At a concentration of 10.0 mM lactate, the highest amount of bacterial cells (1.6 x 10 5 cells/capillary) was measurable. Between 8.0 x 10 4 and 1.0 x 10 5 cells/capillary were determined at concentrations of 100.0, 1.0, 0.1 and 0.01 mM lactate. The effect of thiosulphate was not as significant as the effect of lactate: at a concentration of 10.0 mM thiosulphate, 5.0 x 10 4 cells/capillary, at a concentration of 1.0 mM thiosulphate, 3.0 x 10 4 cells/capillary and at a concentration of 0.1 mM thiosulphate, 2.0 x 10 4 cells/capillary were determined. Finally, the effect of the highly toxic biocide tributyltin chloride was tested. The cell numbers of D. vulgaris were not affected by concentrations of 0.01 and 0.1% tributyltin chloride compared to the control assay (4.1 x 10 4 and 3.8 x 10 4 cells/capillary). This result is important for the application of tributyltin chloride compounds. Consequently, the use of the modified capillary assay enabled fast tests and yielded reproducible results for measurements of chemotactic activities of Acidithiobacillus ferrooxidans and Desulfovibrio vulgaris. Dependent on the concentration, the impact of biocides or inhibitory substances on the main bacteria involved in bioleaching and corrosion processes could be detected as a matter of routine.

Using the echelle-A grating of the GHRS, the authors have observed the C II λλ1335, 1336 emission lines of the nearby (d = 13.3 pc) star system Capella (G8 III + G1 III). Interstellar C II absorption features are detected within both stellar emission lines. The ground state and excited state C II column densities derived from these absorption lines imply an electron density of n e = 0.11 (+0.12, -0.06) cm 3 in the local interstellar medium (LISM). Unlike previous derivations of n e from Mg II/ Mg I ratios, the density suggested by the C II lines is independent of assumptions about ionization equilibrium. Current estimates of the H I density in the LISM are in the range 0.1 – 0.2 cm-3. The He I/H I ratio toward the white dwarf G191-B2B, which is only 7° from Capella, has been measured to be 0.068 – 0.082 from Extreme Ultraviolet Explorer data. These results indicate hydrogen and helium ionization fractions toward Capella of X(H) = 0.45±0.25 and X(He) = 0.57± 0.23, respectively, confirming that hydrogen and helium are substantially ionized in the LISM. (43 Ref.)

The authors give the main relations between fundamental and derived constants in analytical and numerical forms. Then, they enumerate and comment results of determinations of parameters of the figure and gravity field of the Earth, solar parallax, constant of lunar equation, the masses of planets, the constants of aberration, of nutation and of precession and give an extensive list of references.

Als Erganzung einer Arbeit von D. K. KULIKOW werden die Anfangswerte der Integralfunktion von numerisch zu integrierenden Differentialgleichungen I. Ordnung fur konstante 4., 6., 8. oder 10. Differenzen in Abhangigkeit von den fur den entsprechenden Argumentenbereich gegebenen I. Ableitung bestimmt und die Ausdrucke von KULIKOW fur Doppelintegrale umgeformt.