3,272 research outputs found
Tunneling induced electron transfer between separated protons
We study electron transfer between two separated nuclei using local control
theory. By conditioning the algorithm in a symmetric system formed by two
protons, one can favored slow transfer processes, where tunneling is the main
mechanism, achieving transfer efficiencies close to unity assuming fixed
nuclei. The solution can be parametrized using sequences of pump and dump pi
pulses, where the pump pulse is used to excite the electron to a highly excited
state where the time for tunneling to the target nuclei is on the order of
femtoseconds. The time delay must be chosen to allow for full population
transfer via tunneling, and the dump pulse is chosen to remove energy from the
state to avoid tunneling back to the original proton. Finally, we study the
effect of the nuclear kinetic energy on the transfer efficiency. Even in the
absence of relative motion between the protons, the spreading of the nuclear
wave function is enough to reduce the yield of electronic transfer to less than
one half.Comment: 7 pages, 8 figure
Rapid metaphase and interphase detection of radiation-induced chromosome aberrations in human lymphocytes by chromosomal suppression in situ hybridization
Chromosomal in situ suppression (CISS)-hybridization of biotinylated phage DNA-library inserts from sorted human chromosomes was used to decorate chromosomes 1 and 7 specifically from pter to qter and to detect structural aberrations of these chromosomes in irradiated human peripheral lymphocytes. In addition, probe pUC1.77 was used to mark the Iq12 subregion in normal and aberrant chromosomes 1. Low LET radiation (60Co--rays; 1.17 and 1.33 MeV) of lymphocyte cultures was performed with various doses (D = 0, 2, 4, 8 Gy) 5 h after stimulation with phytohaemagglutinin. Irradiated cells were cultivated for an additional 67 h before Colcemid arrested metaphase spreads were obtained. Aberrations of the specifically stained chromosomes, such as deletions, dicentrics, and rings, were readily scored after in situ hybridization with either the 1q12 specific probe or DNA-library inserts. By the latter approach, translocations of the specifically stained chromosomes could also be reliably assessed. A linear increase of the percentage of specifically stained aberrant chromosomes was observed when plotted as a function of the square of the dose D. A particular advantage of this new approach is provided by the possibility to delineate numerical and structural chromosome aberrations directly in interphase nuclei. These results indicate that cytogenetic monitoring of ionizing radiation may be considerably facilitated by CISS-hybridization
Managing regional innovation strategy projects
This paper presents a qualitative interview study with 28 RIS project managers that aimed at understanding whether or not this is true in the context of regional innovation and what the specifics of managing regional innovation projects are. In taking up a recent claim for policy intervention studies which allow to “derive precise suggestions for their design and management”. The study investigated the interrelation between the agility of the management approach and the achievements of RIS projects. Findings raise serious issues concerning methodological approaches for the management of regional innovation projects and question whether the recent public funding mechanisms can lead to sustainable project results
Addressing Compiler Errors: Stack Overflow or Large Language Models?
Compiler error messages serve as an initial resource for programmers dealing
with compilation errors. However, previous studies indicate that they often
lack sufficient targeted information to resolve code issues. Consequently,
programmers typically rely on their own research to fix errors. Historically,
Stack Overflow has been the primary resource for such information, but recent
advances in large language models offer alternatives. This study systematically
examines 100 compiler error messages from three sources to determine the most
effective approach for programmers encountering compiler errors. Factors
considered include Stack Overflow search methods and the impact of model
version and prompt phrasing when using large language models. The results
reveal that GPT-4 outperforms Stack Overflow in explaining compiler error
messages, the effectiveness of adding code snippets to Stack Overflow searches
depends on the search method, and results for Stack Overflow differ
significantly between Google and StackExchange API searches. Furthermore, GPT-4
surpasses GPT-3.5, with "How to fix" prompts yielding superior outcomes to
"What does this error mean" prompts. These results offer valuable guidance for
programmers seeking assistance with compiler error messages, underscoring the
transformative potential of advanced large language models like GPT-4 in
debugging and opening new avenues of exploration for researchers in AI-assisted
programming
How Young “Early Birds” Prefer Preservation, Appreciation and Utilization of Nature
Since the 1990s, the Two Major Environmental Value model (2-MEV) has been applied to measure adolescent environmental attitudes by covering two higher order factors: (i) Preservation of Nature (PRE) which measures protection preferences and (ii) Utilization of Nature (UTL) which quantifies preferences towards exploitation of nature. In addition to the 2-MEV scale, we monitored the Appreciation of Nature (APR) which, in contrast to the UTL, monitors the enjoyable utilization of nature. Finally, we employed the Morningness⁻Eveningness Scale for Children (MESC) which monitors the diurnal preferences and associates with personality and behavioral traits. In this study, we analyzed data from 429 Irish students (14.65 years; ±1.89 SD) with the aim of reconfirming the factor structure of the 2-MEV+APR and monitoring the relationship between the MESC and the environmental values (PRE, UTL, APR). Our findings identified a significant association between PRE and APR with MESC. In addition, we observed a gender difference. Our results suggest that morningness preference students are more likely to be protective of and appreciative towards nature. Recommendations for outreach programs as well as conclusions for environmental education initiatives in general are discussed
Safety and efficacy of high-dose intravenous iron carboxymaltose vs. iron sucrose for treatment of postpartum anemia
Objective: The purpose of this study is to compare the safety and efficacy of intravenous (IV) high-dose iron carboxymaltose (ICM) with iron sucrose (IS) for the treatment of postpartum anemia. Study design: We performed a retrospective cohort study with 210 anemic inpatient women in the postpartum period who received IV high-dose ICM (15 mg/kg; maximum, 1000 mg) or IS (2×200 mg), respectively. Safety and tolerability of both groups were compared on the basis of reported systemic and local adverse events. The cohorts were matched for baseline characteristics and their initial hemoglobin (Hb) values. The secondary endpoint included drug efficacy assessment by measurement of Hb level increase up to 8 days after treatment. Results: Rapid administration of high ICM doses was as well tolerated as IS with overall adverse events of 5% (ICM) vs. 6% (IS). The most common complaint was burning and pain at the injection site. ICM was as effective as IS in changing Hb levels from the baseline. There was no difference in the mean daily Hb increase between the groups. Women with severe anemia showed the most effective responsiveness. Conclusions: IV ICM is as safe as IS in the management of postpartum (IDA) iron deficiency anemia despite five times of higher dosage. Both drugs are effective and offer a rapid normalization of Hb after delivery. The single application of ICM shows advantages of lower incidence of side effects at the injection site, a shorter treatment period, and better patient complianc
Distances between two chromosomes in interphase nuclei as determined with digitized image analysis
20th century minimum and maximum temperature variations analysed on a regional scale in Switzerland: statistical analyses of observational data
The major aim of this study is to describe in a detailed manner the 20th century minimum and maximum temperature variations in Switzerland and to assess whether the magnitude of the secular warming and its interannual to interdecadal fluctuations show common seasonal patterns in different climatological regions. In a first step different climatological regions could successfully be established for all four seasons applying a statistical clustering method (Cluster Analysis) to the minimum and maximum temperature time series of a maximum number of climatological stations situated in different parts of the country. A Principal Component Analysis is preceding the actual clustering method which allows to compare the climatological station time series based on minimum and maximum temperature variations as well as on specific station related characteristics. Each of the resulting clusters aggregates a number of climatological stations, which follow a similar temporal development in the temperature data and own comparable station related characteristics. These clusters can therefore be considered as representative of a certain climatological region, which however is not necessarily geographically uniform. The clustering is carried out separately for two different climatological parameters in all four seasons, namely minimum and maximum temperatures in winter, spring, summer and autumn. The resulting clustering patterns reflect a strong dependency upon these climatological parameters as well as upon the seasons. Typical seasonal night-time and day-time temperature distributions over complex terrain have a determining influence on the emerging clustering patterns, which are similar in winter and autumn and in spring and summer. The classic fog and stratus areas combined with the particular cold air drainage over complex terrain have a determining influence on the clustering pattern in winter and autumn and thus the clusters are mainly specified through altitudinal stages. In spring and summer the clustering patterns are still related to the altitude they show however an additional dependency on specific geographical areas. Out of each of the eight clustering patterns three main regions emerged which could be related to the three most contrasting climatic areas in Switzerland and identified as "low altitudes, north", "high altitudes", and "low altitudes, south". The description of the following analyses is restricted to these three regions. The quantitative analyses of the minimum and maximum temperature trends and fluctuations over the 20th century are carried out on regional mean time series computed for each cluster. A new and very detailed description for the seasonal minimum and maximum temperature variations during the 20th century in Switzerland results. Secular warming trends are detected for both, minimum and maximum temperatures. The magnitudes differ mostly between the seasons. The minimum temperatures show generally higher trend estimates than the maximum temperatures with a more pronounced secular warming in winter and autumn. Analysing the temperatures on a decadal scale an abrupt warming is detected during the 1990s, which is especially emphasised for winter minimum temperatures in the region "high altitudes". A further warm period during the 20th century occurred from 1940 to 1950. In contrast to the warming at the end of the century this mid-century warming is most evident in maximum temperatures during spring and summer in the regions "low altitudes, north" and "high altitudes". The long- term decadal trend shows that minimum and maximum temperatures in all regions and seasons except for autumn are persistently increasing since 1980. The autumn temperatures play a special role since their secular warming trend is principally related to rather cold temperatures in the beginning of the century and a mild period during the 1980s, which, however, is not extended into the 1990s. These observations lead to the conclusion that a change in the seasonal warming pattern occurred during the last few decades. Analyses of minimum and maximum temperature extremes are supporting the conclusions formulated above. The warming trends as well as the mild phases, which are observed in minimum and maximum temperatures, can generally be related to a warming in both tails of the distribution (warm and cold). The described results can be linked to the 20th century evolution of large and small scale synoptic systems. The North Atlantic Oscillation exerts a high influence on winter weather types in Switzerland. The increasingly positive North Atlantic Oscillation Index during the last two decades most probably generated a changed frequency pattern of the alpine weather types in winter. In the 1990s this is expressed with a higher frequency of warm winter weather types (convective high-pressure and western advective) on the expenses of a major cold type (eastern advective). The frequency analysis of the alpine weather types for the other seasons does not yield as obvious results as for winter. It was found however, that the main warm periods occurring in different seasons during the century (mid-century summer warming; autumn mild phase in the 1980s) can principally be related to an elevated number of convective high-pressure weather types which usually generate milder temperatures. In an additional chapter the climatological regionalisation method, previously used with temperature data is applied to wind gust data. The analyses show that the gust factor between maximum and mean daily wind speeds over complex terrain follow a lognormal distribution. This knowledge in combination with the climatological regionalisation serves to estimate wind gust speed probabilities over the complex terrain of Switzerland according to three types of synoptic weather situations.Das Hauptziel dieser Studie ist eine möglichst detaillierte Beschreibung der Variationen der Minimum- und Maximumtemperaturen während des 20. Jahrhunderts, wobei es von Interesse ist abzuklären, ob der Umfang der Jahrhunderterwärmung sowie die annuellen und dekadalen Schwankungen in verschiedenen Regionen der Schweiz übereinstimmende saisonale Muster aufweisen. In einem ersten Schritt wurde eine möglichst hohe Anzahl von Minimum- und Maximumtemperaturzeitreihen der Landesklimastationen mit einer statistischen Gruppierungsmethode (Clusterananlyse) erfolgreich nach Jahreszeit geordnet. Vor der eigentlichen Gruppierungsmethode wird eine Hauptkomponentenanylse durchgeführt, die es erlaubt, einen Vergleich der Klimastationen anhand der Variationen in Minimum- und Maximumtemperaturen sowie spezifischen stationsbezogenen Eigenschaften vorzunehmen. In jeder dieser so erhaltenen Gruppen werden Klimastationen vereint, welche ähnliche zeitliche Temperaturvariationen aufweisen und deren stationsbezogenen Eigenschaften vergleichbar sind. Somit können diese Gruppen als jeweilige Vertreter einer bestimmten Klimaregion, deren Gebiet jedoch nicht unbedingt geographisch zusammenhängt, angenommen werden. Die Clusteranalyse wird jeweils auf Minimum- und Maximumtemperatur in den vier verschiedenen Jahreszeiten Winter, Frühling, Sommer und Herbst angewendet. Die daraus resultierenden verschiedenen Gruppierungsmuster widerspiegeln eine starke Abhängigkeit von den Klimaparametern und den Jahreszeiten. Die saisontypische Nachtund Tagestemperaturverteilung über komplexem Terrain übt einen bestimmenden Einfluss aus auf die sich bildenden Gruppierungsmuster, welche im Winter und im Herbst sowie im Frühling und im Sommer am ähnlichsten sind. Während den kühlen Jahreszeiten wird die Gruppierung der Klimastationen von den typischen herbstlichen und winterlichen Nebel- und Stratusgebieten wie auch vom Absinkverhalten der Kaltluft über komplexem Terrain am stärksten beeinflusst. Das Gruppierungsmuster ist daher eng verbunden mit der Höhe über Meer, auf welcher sich eine Klimastation befindet. Während den warmen Jahreszeiten ist die Verbindung zur Höhe immer noch zu finden, die Zugehörigkeit zu einer geographischen Region ist jedoch genauso massgebend. Drei bestimmte Klimaregionen, welche mit den drei gegensätzlichsten Klimazonen in der Schweiz in Verbindung gebracht werden können, treten innerhalb der acht erhaltenen Gruppierungsmuster regelmässig auf. Die drei Regionen werden dementsprechend benannt als: "tiefere Lagen, Nord", "hohe Lagen" und "tiefere Lagen, Süd". Die Beschreibung der Analysen beschränkt sich im weiteren Verlauf der Arbeit auf diese drei Regionen. Die weiteren quantitativen Analysen, welche der Erfassung des Trends in den Minimumund Maximumtemperaturen und deren Schwankungen während des 20. Jahrhunderts dienen, basieren auf mittleren regionalen Zeitreihen, die für jede einzelne Gruppe berechnet werden. Daraus geht eine neue und sehr detaillierte Beschreibung der saisonalen Minimum- und Maximumtemperaturvariationen während des 20. Jahrhunderts hervor. Die Minimum- sowie die Maximumtemperaturen unterliegen einer allgemeinen Erwärmung, welche sich in ihrem Ausmass zwischen den verschiedenen Jahreszeiten am meisten unterscheidet. Die Minimumtemperaturen weisen eine grundsätzlich grössere Erwärmung als die Maximumtemperaturen auf, was sich am stärksten im Winter und im Herbst äussert. Eine dekadal skalierte Untersuchung der Temperaturen lässt darauf schliessen, dass die 90er Jahre einer abrupten Erwärmung unterlagen, welche in den winterlichen Minimumtemperaturen in der Region "hohe Lagen" besonders nachdrücklich ist. Zwischen 1945 und 1950 ist eine weitere Warmphase zu finden, welche im Gegensatz zur Warmphase in den 90er Jahren vor allem in den Maximumtemperaturen des Frühlings und des Sommers in den Regionen "tiefere Lagen, Nord" und "hohe Lagen" ermittelt werden kann. Der dekadal skalierte Langzeittrend weist für alle Regionen und Jahreszeiten, ausser dem Herbst, von 1980 an kontinuierlich ansteigende Temperaturen auf. Die Herbsttemperaturen nehmen eine etwas spezielle Rolle ein, da sie nicht von einer Erwärmung in den 90er Jahren geprägt werden. Die starke Erwärmung, die ihnen über das Jahrhundert hinweg eigen, ist kann vor allem auf kalte Werte am Anfang des Jahrhunderts und eine milde Phase während den 80er Jahren zurückgeführt werden. Diese Beobachtungen lassen auf einen Wandel des jahreszeitlichen Erwärmungsmusters über die letzten Dekaden hinweg schliessen. Die bisher beschriebenen Resultate können auf den Ergebnissen aus der Analyse der Minimum- und Maximumtemperaturextreme abgestützt werden. Die gefundenen Erwärmungstrends sowie die verschiedenen Warmphasen stehen in enger Verbindung mit einer Erwärmung der Extremwerte in beiden Enden (extrem warm und extrem kalt) der Minimum- und Maximumtemperaturverteilung. Die Ergebnisse können in einen direkten Zusammenhang mit der Entwicklung diverser klein- und grossräumiger synoptischer Systeme im 20. Jahrhundert gebracht werden. Die Nordatlantische Oszillation übt einen grossen Einfluss auf die Wetterlagen in der Schweiz während des Winters aus. Mit grosser Wahrscheinlichkeit ist der über die letzten zwei Jahrzehnte hinweg zunehmend positive Nordatlantische Oszillationsindex bezeichnend für einen Wandel im Frequenzenmuster der winterlichen Wetterlagen. Es steht fest, dass während der 90er Jahre ein vermehrtes Auftreten von sogenannten "warmen" winterlichen Wetterlagen, wie konvektive Hochdrucklagen und advektive Westlagen, einhergeht mit einem markanten Rückgang der sogenannten "kalten" winterlichen Wetterlagen wie sie die advektiven Ostlagen darstellen. Die Frequenzanalyse der Wetterlagen in den anderen Jahreszeiten ergibt keine so klaren Resultate. Die grossen Warmphasen während des Jahrhunderts (Sommer Mitte Jahrhundert, Herbst in den 80er Jahren) können jedoch in Verbindung gebracht werden mit einem erhöhten Auftreten von konvektiven Hochdrucklagen, welche für mildere Temperaturen bedeutend sind. In einem zusätzlichen Kapitel wird die klimatologische Regionalisierungsmethode wie sie im vorhergehenden Teil an Temperaturdaten angewendet worden ist an Windgeschwindigkeitsdaten getestet. In der Analyse wird aufgezeigt, dass über komplexem Terrain, der Faktor zwischen den täglichen maximalen und mittleren Windgeschwindigkeiten eine lognormale Verteilung annimmt. In Verbindung mit einer klimatologischen Regionalisierung, welche für drei Arten von synoptischen Wetterlagen vorgenommen wird, dient diese Erkenntnis dazu, die Wahrscheinlichkeit der Windböengeschwindigkeit über dem komplexen Terrain der Schweiz abzuschätzen
Wissensaustausch zwischen Forschung und Praxis erfolgreich gestalten
Um die gesellschaftliche Transformation zu gestalten, wird der Austausch von Wissen zwischen Wissenschaft und Praxis immer wichtiger. Dieser Artikel benennt Prinzipien, Kompetenzen und Rahmenbedingungen für erfolgreichen Wissensaustausch
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