49 research outputs found

    PERTURBATIONS IN THE SPECTRA OF HIGH RYDBERG STATES: CHANNEL INTERACTIONS, STARK AND ZEEMAN EFFECTS

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    Author Institution: Laboratorium fur Physikalische Chemie, ETH-Zurich, 8093 Zurich, SwitzerlandRydberg states of principal quantum number n50n\gg50 have been prepared by irradiation of an atomic beam of xenon with vacuum ultraviolet (VUV) radiation. Narrowband submillimeter-wave (THz) radiation was then used to record spectra of transitions from these Rydberg states to higher or lower-lying Rydberg states. The transitions were detected by selective field ionization and recording either the electrons or the ions, the latter offering the advantage of mass selection. Rydberg states of high principal quantum number are extremely sensitive to their environment, which can be exploited to characterize the experimental conditions under which the spectroscopic measurements are carried out nderline{\textbf{21}}, 385, (2002).}. The high resolution achieved in the experiments (better than 100~kHz) enabled the study of the spectral lineshapes and line positions in dependence of weak electric (down to below 100μ100\muV/cm) and magnetic fields (down to a few μ\muT), and of the density of Rydberg atoms and ions generated in the experimental volume. The experiments rely on the use of a pulsed, broadly tunable, laser-based source of THz radiation nderline{\textbf{93}}, 131105, (2008).} for survey scans, and of a phase- and frequency-stabilized submillimeter-wave backward-wave oscillator-based radiation source nderline{\textbf{39}}, 831, (2006).} for precision measurements. To illustrate the use of these sources, we present the results of the spectroscopic investigations of the hyperfine structure of 129^{129}Xe Rydberg states in spectral regions where s-d interactions are expected to play a role

    Feather Corticosterone Measurements and Behavioral Observations in the Great White Pelican (Pelecanus onocrotalus) Living under Different Flight Restraint Conditions in German Zoos

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    The welfare of zoo birds kept under flight restraint is a frequently discussed topic. Therefore, this study was conducted with one of the most regularly kept types of deflighted birds in German zoos, the great white pelican, to find scientific data regarding welfare assessments of deflighted birds. The detection of corticosterone in feathers (CORTf) as a stress indicator for birds is an almost completely noninvasive form of measurement meant to evaluate the effects of deflighting birds in zoos. Three groups of animals were compared: irreversibly deflighted pelicans that were pinioned or extirpated, reversibly deflighted individuals that were feather-clipped, and airworthy pelicans that were able to fly. Combining two independent research methods, behavioral observation and the measurement of CORTf levels of great white pelicans, we aimed to obtain an objective overview of whether deflighted birds showed differences in CORTf or behavior compared to airworthy birds. As a result of the analysis, we found no significant differences in CORTf between flight-restricted and airworthy birds. However, reversibly deflighted pelicans had higher CORTf values than irreversibly deflighted and airworthy pelicans. In addition, pelicans living in groups consisting of more than 10 individuals showed lower CORTf values than pelicans in groups of less than 10 individuals. "Fluttering" behavior was significantly associated with higher CORTf values. In conclusion, the flight restriction of great white pelicans does not seem to impact the welfare indicators assessed in this study, adrenal activity, or behavior. The data show that the living conditions of pelicans (such as group size) may influence the welfare of these birds. To confirm this, further studies on other ground- and water-based birds are needed to provide more scientific data on animal welfare and living conditions in zoos. The pinioning of birds was previously one of the most-accepted forms of mutilation in zoos. Despite a lack of knowledge on the effects of deflighting procedures with regard to the well-being of deflighted birds, pelicans are often reversibly deflighted by feather-clipping to keep them in open enclosures, including those with ponds without netting. In the present study, we focused on the welfare implications of flight restraint on one of the most commonly kept types of birds in German zoos, the great white pelican. A combination of behavioral observations and feather corticosterone concentrations (CORTf) of pelicans with different deflighting statuses (i.e., irreversibly deflighted, reversibly deflighted, and airworthy) was used to evaluate the effects of deflighting status on pelican welfare. We observed 215 individuals in 21 different German zoos. The pelicans lived in differently designed exhibits. An ethogram for these species was developed and their behavior was evaluated by scan sampling. Feather samples from 182 individuals were collected to determine if different deflighting conditions influenced the CORTf and therefore stress levels. The hypothesis was that the CORTf values of airworthy pelicans differ from those of deflighted pelicans. Tendencies with regard to the flight status groups were found. Conversely, reversibly deflighted pelicans had higher CORTf levels than irreversible deflighted and airworthy pelicans. Tendencies with regard to CORTf values and the group size of the kept pelicans were observed. The CORTf values were lower in groups consisting of more than 10 animals. In addition, the frequency of fluttering behavior was positively associated with CORTf values. Pelicans that frequently showed fluttering had higher CORTf values. Therefore, fluttering behavior might be considered a sign of stress levels in pelicans. This study is one of the first important steps in assessing the impact of deflighting procedures on the welfare of great white pelicans kept in zoos

    Feather corticosterone measurements of greater flamingos living under different forms of flight restraint

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    This research was supported by the German Association of Zoological Gardens (Verband der Zoologischen Gärten e.V, VdZ) with 20,000 €.Deflighting zoo birds is a practice that receives increasing criticism due to its presumed incompatibility with animal welfare. To our knowledge, this is the first approach to address this problem in a scientific way. To do this, we compared feather corticosterone (CORTf) from Greater Flamingos (Phoenicopterus roseus, n = 151) of different flight status (i.e., pinioned, feather clipped, airworthy) from twelve different zoological institutions. To complement the hormone measurements, behavioral observations (scan samplings) were conducted prior to feather sampling within the presumed time frame of feather growth. We hypothesized that CORTf of the deflighted flamingos would differ from CORTf of their airworthy conspecifics. No significant difference in CORTf was found between the three groups, and our hypothesis was rejected. However, the impact of the institution itself (i.e., the housing conditions) proved to be the most dominant variable (variance between the institutions = 53.82%). Due to high variability, the behavioral observations were evaluated descriptively but did not give rise to doubt the findings in CORTf. Therefore, we assume that the method of flight restraint of Greater Flamingos does not have a measurable effect on CORTf. We consider this model for evaluating animal welfare of zoo birds a useful tool and provide ideas for further adjustments for consecutive studies

    Research roadmap for nanosafety - Part III: Closer to the market (CTTM)

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    Nano-products and nano-enabled applications need a clear and easy-to-follow human and environmental safety framework for the development along the innovation chain from initial idea to market and beyond that facilitates navigation through the complex regulatory and approval processes under which different product categories fall. The missing framework results in a lack of (i) solid data regarding roadblocks to market penetration of nano-enabled products as well as the absence of (ii) transparency in terms of which products (e.g. containing nanomaterials (NMs); nano-enabled products) are on the market (e.g. registries) and voluntary schemes and labelling requirements for cosmetics and food, which processes are used for manufacturing nano-enabled products, and (iii) meager inclusiveness in the dialogue (between all stakeholders) most likely exist as a result of the missing framework. The Closer-to-the-Market-Roadmap (abbrev. CTTM) aims at speeding up the progress towards market implementation of nanotechnologies by outlining the steps needed to develop such a framework. In its current form it is addressed towards policy makers, but the ultimate framework will be designed for use by SME and enterprise organisations

    El benestar de les aus amb vol restringit

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    El benestar de les aus de zoològic amb el vol restringit ha estat objecte d'un estudi realitzat per investigadors de la UAB i de la Universitat de Freie en pelicans de diversos recintes d'Alemanya. Els científics han avaluat el benestar d'aquestes aus a través de l'estudi del seu comportament i dels nivells de l'hormona de l'estrès corticosterona. Els resultats mostren que la restricció de vol no influeix en els criteris de benestar avaluats, tot i que sí que ho fan les condicions de l'entorn. Per confirmar-los, però, calen més dades científiques sobre l'impacte en el benestar d'altres espècies d'aus.El bienestar de las aves de zoológico con el vuelo restringido ha sido objeto de un estudio realizado por investigadores de la UAB y la Universidad de Freie en pelícanos de diversos recintos de Alemania. Los científicos han evaluado el bienestar de estas aves a través del estudio de su comportamiento y de los niveles de la hormona del estrés corticosterona. Los resultados muestran que la restricción de vuelo no influye en los criterios de bienestar avaluados, aunque sí que lo hacen las condiciones del entorno. Para confirmarlos, no obstante, son necesarios más datos científicos sobre otras especies de aves.The welfare of zoo birds kept under flight restraint has been studied by researchers of the UAB and the University of Freie with great white pelicans from German zoos. The scientists have evaluated the well-being of the animals through the ethological study and the levels of stress hormone corticosterone. The results show that the flight restriction does not influence the assessed welfare criteria, although the environmental conditions do. To confirm this, further studies are needed to provide more scientific data on other bird animals in captivity

    Time-dependent changes in mortality and transformation risk in MDS

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    In myelodysplastic syndromes (MDSs), the evolution of risk for disease progression or death has not been systematically investigated despite being crucial for correct interpretation of prognostic risk scores. In a multicenter retrospective study, we described changes in risk over time, the consequences for basal prognostic scores, and their potential clinical implications. Major MDS prognostic risk scoring systems and their constituent individual predictors were analyzed in 7212 primary untreated MDS patients from the International Working Group for Prognosis in MDS database. Changes in risk of mortality and of leukemic transformation over time from diagnosis were described. Hazards regarding mortality and acute myeloid leukemia transformation diminished over time from diagnosis in higher-risk MDS patients, whereas they remained stable in lower-risk patients. After approximately 3.5 years, hazards in the separate risk groups became similar and were essentially equivalent after 5 years. This fact led to loss of prognostic power of different scoring systems considered, which was more pronounced for survival. Inclusion of age resulted in increased initial prognostic power for survival and less attenuation in hazards. If needed for practicability in clinical management, the differing development of risks suggested a reasonable division into lower- and higher-risk MDS based on the IPSS-R at a cutoff of 3.5 points. Our data regarding time-dependent performance of prognostic scores reflect the disparate change of risks in MDS subpopulations. Lower-risk patients at diagnosis remain lower risk whereas initially high-risk patients demonstrate decreasing risk over time. This change of risk should be considered in clinical decision making

    Differing clinical features between Japanese and Caucasian patients with myelodysplastic syndromes:Analysis from the International Working Group for Prognosis of MDS

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    Clinical features of myelodysplastic syndromes (MDS) could be influenced by many factors, such as disease intrinsic factors (e.g., morphologic, cytogenetic, molecular), extrinsic factors (e.g, management, environment), and ethnicity. Several previous studies have suggested such differences between Asian and European/USA countries. In this study, to elucidate potential differences in primary untreated MDS between Japanese (JPN) and Caucasians (CAUC), we analyzed the data from a large international database collected by the International Working Group for Prognosis of MDS (300 and 5838 patients, respectively). JPN MDS were significantly younger with more severe cytopenias, and cytogenetic differences: less del(5q) and more +1/+1q, -1/del(1p), der(1;7), -9/del(9q), del(16q), and del(20q). Although differences in time to acute myeloid leukemia transformation did not occur, a significantly better survival in JPN was demonstrated, even after the adjustment for age and FAB subtypes, especially in lower, but not in higher prognostic risk categories. Certain clinical factors (cytopenias, blast percentage, cytogenetic risk) had different impact on survival and time to transformation to leukemia between the two groups. Although possible confounding events (e.g., environment, diet, and access to care) could not be excluded, our results indicated the existence of clinically relevant ethnic differences regarding survival in MDS between JPN and CAUC patients. The good performance of the IPSS-R in both CAUC and JP patients underlines that its common risk model is adequate for CAUC and JP
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