181 research outputs found
Hydrobiologische Untersuchungen der GewÀsser in den Kuranlagen von Bad Laer
Die 1978 und 1979 an 5 Stellen gefundenen 50 Tier- und 125 Pflanzengruppen werden aufgelistet. An Algen sind nachzuweisen: 8 Cyanophyta, 1 Chrysophyta, 85 Diatomeae (Bacillariophyta), 4 Xanthophyta, 3 Euglenophyta, 14 Chlorophyta und 1 Conjugatophyta. Die Auswertung der Artenliste von sauerstoffliebenden Diatomeen wird korrelliert mit den elektrometrisch gemessenen 02-Werten. Die salzliebenden und oligohaloben Diatomeen bestĂ€tigen den Solecharakter. Die an Hand von relevanten Algen errechneten Saprobien-Indexwerte ergaben an allen ProbenahmesteIlen die WassergĂŒte 1-11. Die bei den physikalischen und chemischen Untersuchungen ermittelten Stickstoffwerte, die sehr hoch lagen, konnten diese WassergĂŒte nicht bestĂ€tigen. Der im Wasser gelöste Sauerstoff in den Probenahmestellen 11 bis V lag im Mittel zum Teil ĂŒber dem SĂ€ttigungswert. Der Quellkolk machte hier eine Ausnahme mit einem mittleren SĂ€ttigungsfehlbetrag von 54%. Die Sauerstoffzehrung verhielt sich in umgekehrter Weise. Im Quellkolk war sie gering und in den folgenden Stellen zeitweise sehr hoch, konnte aber nie den Sauerstoffhaushalt der untersuchten GewĂ€sser gefĂ€hrden
Die Algenvegetation der Nette bei OsnabrĂŒck
Es wird versucht den Saprobienindex oder die WassergĂŒteklasse des Nette- Flusses anhand der vorgefundenen Algen zu ermitteln. Begleitende physikalisch-chemische Untersuchungen zeigen differente ökologische Bedingungen der Beobachtungspunkte auf
Die pennaten Diatomeen der oberen und mittleren Hase : mit Tabellen
280 Arten der pennaten Diatomeen konnten in drei Jahren an fĂŒnf Entnahmesteilen in der Hase beobachtet werden. Die unterschiedliche Zusammensetzung ihrer Assoziationen in diesen verschiedenen Biotopen lassen aut- und synökologische ZusammenhĂ€nqe erkennen, die mit differenten ökologischen Bedingungen der Beobachtungspunkte korrelieren, z. B der Eutrophierung
Die WassergĂŒte des Goldbaches bei Hagen am Teutoburger Wald in seinem Oberlauf und in einem seiner ZuflĂŒsse im Jahr 1982
Es wurde versucht, die WassergĂŒte des Goldbaches, der durch gewerblich genutzte Fischteiche in seinem ursprĂŒnglichen Zustand gestört ist, an. ausgesuchten Stellen zu ĂŒberprĂŒfen. Gleichzeitig sollte festgestellt werden, ob die genannten Fischteiche die WasserqualitĂ€t beeinflussen. Die WassergĂŒte ist biologisch durch die vorgefundenen Algen und Makroorganismen errechnet worden. Ein ZufluĂ des Goldbaches wurde ebenfalls ĂŒberprĂŒft. Die Untersuchungen sind durch hydrochemische und -physikalische Daten begleitet worden
Effect of Exercise-Induced Reductions in Blood Volume on Cardiac Output and Oxygen Transport Capacity
We wanted to demonstrate the relationship between blood volume, cardiac size, cardiac output and maximum oxygen uptake ([Formula: see text] O(2max)) and to quantify blood volume shifts during exercise and their impact on oxygen transport. Twenty-four healthy, non-smoking, heterogeneously trained male participants (27 ± 4.6 years) performed incremental cycle ergometer tests to determine [Formula: see text] O(2max) and changes in blood volume and cardiac output. Cardiac output was determined by an inert gas rebreathing procedure. Heart dimensions were determined by 3D echocardiography. Blood volume and hemoglobin mass were determined by using the optimized CO-rebreathing method. The [Formula: see text] O(2max) ranged between 47.5 and 74.1 mLâ
kg(â1)â
min(â1). Heart volume ranged between 7.7 and 17.9 mLâ
kg(â1) and maximum cardiac output ranged between 252 and 434 mLâ
kg(â1)â
min(â1). The mean blood volume decreased by 8% (567 ± 187 mL, p = 0.001) until maximum exercise, leading to an increase in [Hb] by 1.3 ± 0.4 gâ
dL(â1) while peripheral oxygen saturation decreased by 6.1 ± 2.4%. There were close correlations between resting blood volume and heart volume (r = 0.73, p = 0.002), maximum blood volume and maximum cardiac output (r = 0.68, p = 0.001), and maximum cardiac output and [Formula: see text] O(2max) (r = 0.76, p < 0.001). An increase in maximum blood volume by 1,000 mL was associated with an increase in maximum stroke volume by 25 mL and in maximum cardiac output by 3.5 Lâ
min(â1). In conclusion, blood volume markedly decreased until maximal exhaustion, potentially affecting the stroke volume response during exercise. Simultaneously, hemoconcentrations maintained the arterial oxygen content and compensated for the potential loss in maximum cardiac output. Therefore, a large blood volume at rest is an important factor for achieving a high cardiac output during exercise and blood volume shifts compensate for the decrease in peripheral oxygen saturation, thereby maintaining a high arteriovenous oxygen difference
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Effects of 3 Weeks of Oral Low-Dose Cobalt on Hemoglobin Mass and Aerobic Performance
Introduction: Cobalt ions (Co2+) stabilize HIFa and increase endogenous erythropoietin (EPO) production creating the possibility that Co2+ supplements (CoSupp) may be used as performance enhancing substances. The aim of this study was to determine the effects of a small oral dosage of CoSupp on hemoglobin mass (Hbmass) and performance with the objective of providing the basis for establishing upper threshold limits of urine [Co2+] to detect CoSupp misuse in sport. Methods: Twenty-four male subjects participated in a double-blind placebo-controlled study. Sixteen received an oral dose of 5mg of ionized Co2+ per day for 3 weeks, and eight served as controls. Blood and urine samples were taken before the study, during the study and up to 3 weeks after CoSupp. Hbmass was determined by the CO-rebreathing method at regular time intervals, and VO2max was determined before and after the CoSupp administration period. Results: In the Co2+ group, Hbmass increased by 2.0 +/- 2.1% (p < 0.001) while all the other analyzed hematological parameters did not show signi fi cant interactions of time and treatment. Hemoglobin concentration ([Hb]) and hematocrit (Hct) tended to increase (p = 0.16, p = 0.1) and also [EPO] showed a similar trend (baseline: 9.5 +/- 3.0, after 2 weeks: 12.4 +/- 5.2 mU/ml). While mean VO2max did not change, there was a trend for a positive relationship between changes in Hbmass and changes in VO2max immediately after CoSupp (r = 0.40, p = 0.11). Urine [Co2+] increased from 0.4 +/- 0.3 to 471.4 +/- 384.1 ng/ml (p < 0.01) and remained signi fi cantly elevated until 2 weeks after cessation. Conclusion: An oral Co2+ dosage of 5 mg/day for 3 weeks effectively increases Hbmass with a tendency to increase hemoglobin concentration ([Hb]) and hematocrit (Hct). Because urine Co2+ concentration remains increased for 2 weeks after cessation, upper limit threshold values for monitoring CoSupp can be established
The loopy UV line profiles of RU Lupi: accretion, outflows, and fluorescence
We present far-ultraviolet spectra of the classical T Tauri star RU Lupi
covering the 912-1710 A spectral range, as observed by the HST/STIS and FUSE
satellites. We use these spectra, which are rich in emission and absorption
lines, to probe both the accreting and outflowing gas. Absorption in the
Ly-alpha profile constrains the extinction to A_V=0.07 mag, which we confirm
with other diagnostics. We estimate a mass accretion rate of
(5\pm2)\times10^{-8}$ M_\odot/yr using the optical-NUV accretion continuum. The
accreting gas is also detected in bright, broad lines of C IV, Si IV, and N V,
which all show complex structures across the line profile. Many other emission
lines, including those of H_2 and Fe II, are pumped by Ly-alpha. RU Lupi's
spectrum varies significantly in the FUV; our STIS observations occurred when
RU Lupi was brighter than several other observations in the FUV, possibly due
to a high mass accretion rate.Comment: in press, to be published in June AJ. 19 pages text, 18 Figures, 10
Table
CoRoT photometry and high-resolution spectroscopy of the interacting eclipsing binary AU Mon
Analyses of very accurate CoRoT space photometry, past Johnson V
photoelectric photometry and high-resolution \'echelle spectra led to the
determination of improved and consistent fundamental stellar properties of both
components of AU Mon. We derived new, accurate ephemerides for both the orbital
motion (with a period of 11.113d) and the long-term, overall brightness
variation (with a period of 416.9d) of this strongly interacting Be + G
semi-detached binary. It is shown that this long-term variation must be due to
attenuation of the total light by some variable circumbinary material. We
derived the binary mass ratio = 0.17\p0.03 based on the
assumption that the G-type secondary fills its Roche lobe and rotates
synchronously. Using this value of the mass ratio as well as the radial
velocities of the G-star, we obtained a consistent light curve model and
improved estimates of the stellar masses, radii, luminosities and effective
temperatures. We demonstrate that the observed lines of the B-type primary may
not be of photospheric origin. We also discover rapid and periodic light
changes visible in the high-quality residual CoRoT light curves. AU Mon is put
into perspective by a comparison with known binaries exhibiting long-term
cyclic light changes.Comment: Accepted for publication in MNRA
Influence of variability of material mechanical properties on seismic performance of steel and steel-concrete composite structures
Modern standards for constructions in seismic zones allow the construction of buildings able to dissipate the energy of the seismic input through an appropriate location of cyclic plastic deformations involving the largest possible number of structural elements, forming thus a global collapse mechanisms without failure and instability phenomena both at local and global level. The key instrument for this purpose is the capacity design approach, which requires an appropriate selection of the design forces and an accurate definition of structural details within the plastic hinges zones, prescribing at the same time the oversizing of non-dissipative elements that shall remain in the elastic field during the earthquake. However, the localization of plastic hinges and the development of the global collapse mechanism is strongly influenced by the mechanical properties of materials, which are characterized by an inherent randomness. This variability can alter the final structural behaviour not matching the expected performance. In the present paper, the influence of the variability of material mechanical properties on the structural behaviour of steel and steel/concrete composite buildings is analyzed, evaluating the efficiency of the capacity design approach as proposed by Eurocode 8 and the possibility of introducing an upper limitation to the nominal yielding strength adopted in the design
External validation of molecular subtype classifications of colorectal cancer based on microsatellite instability, CIMP, BRAF and KRAS
Background: Competing molecular classification systems have been proposed to complement the TNM staging system for a better prediction of survival in colorectal cancer (CRC). However, validation studies are so far lacking. The aim of this study was to validate and extend previously published molecular classifications of CRC in a large independent cohort of CRC patients.
Methods: CRC patients were recruited into a population-based cohort study (DACHS). Molecular subtypes were categorized based on three previously published classifications. Cox-proportional hazard models, based on the same set of patients and using the same confounders as reported by the original studies, were used to determine overall, cancer-specific, or relapse-free survival for each subtype. Hazard ratios and confidence intervals, as well as Kaplan-Meier plots were compared to those reported by the original studies.
Results: We observed similar patterns of worse survival for the microsatellite stable (MSS)/BRAF-mutated and MSS/KRAS-mutated subtypes in our validation analyses, which were included in two of the validated classifications. Of the two MSI subtypes, one defined by additional presence of CIMP-high and BRAF-mutation and the other by tumors negative for CIMP, BRAF and KRAS-mutations, we could not confirm associations with better prognosis as suggested by one of the classifications. For two of the published classifications, we were able to provide results for additional subgroups not included in the original studies (men, other disease stages, other locations).
Conclusions: External validation of three previously proposed classifications confirmed findings of worse survival for CRC patients with MSS subtypes and BRAF or KRAS mutations. Regarding MSI subtypes, other patient characteristics such as stage of the tumor, may influence the potential survival benefit. Further integration of methylation, genetic, and immunological information is needed to develop and validate a comprehensive classification that will have relevance for use in clinical practice
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