Bulk dynamics of Brownian hard disks: Dynamical density functional theory versus experiments on two-dimensional colloidal hard spheres

Using dynamical density functional theory (DDFT), we theoretically study Brownian self-diffusion and structural relaxation of hard disks and compare to experimental results on quasi two-dimensional colloidal hard spheres. To this end, we calculate the self and distinct van Hove correlation functions by extending a recently proposed DDFT-approach for three-dimensional systems to two dimensions. We find that the theoretical results for both self- and distinct part of the van Hove function are in very good quantitative agreement with the experiments up to relatively high fluid packing fractions of roughly 0.60. However, at even higher densities, deviations between experiment and the theoretical approach become clearly visible. Upon increasing packing fraction, in experiments the short-time self diffusive behavior is strongly affected by hydrodynamic effects and leads to a significant decrease in the respective mean-squared displacement. In contrast, and in accordance with previous simulation studies, the present DDFT which neglects hydrodynamic effects, shows no dependence on the particle density for this quantity

Defining Fluency

Postcard from Sierra Stopper, during the Linfield College Year Abroad Program in Seville, Spai

Doni di papa Rezzonico per Venezia e Padova

Ascended the papal throne in 1758, Clemente XIII Rezzonico sent many munificent presents to the Serenissima. This paper presents details and news about the Ciborium, donated to the church of San Felice in Venice, here attributed to the roman goldsmith Michelangelo Tucci, and about the Monstrance, sent to Padua’s Cathedral. This piece, that no longer exists, can be known thanks to an unpublished engraving

Giuseppe De Gobbis frescante nella Scuola degli Orefici e Gioiellieri

Based on new archival discoveries, this article reconstructs the various phases of the decoration of the interior of the Scuola degli Orefici e Gioiellieri in Venice. Only at the end of the XVII century, the confraternity bought some properties from Tomaso Querini quondam Angelo in Rialto’s area to make its headquarters. Goldsmiths and Jewellers commissioned restores and adorned their building. In 1781 the ceiling of the Sala Capitolare was painted by Giuseppe De Gobbis

Automated detection and analysis of fluorescence changes evoked by molecular signalling

Fluorescent dyes and genetically encoded fluorescence indicators (GEFI) are common tools for visualizing concentration changes of specific ions and messenger molecules during intra- as well as intercellular communication. While fluorescent dyes have to be directly loaded into target cells and function only transiently, the expression of GEFIs can be controlled in a cell and time-specific fashion, even allowing long-term analysis in living organisms. Dye and GEFI based fluorescence fluctuations, recorded using advanced imaging technologies, are the foundation for the analysis of physiological molecular signaling. Analyzing the plethora of complex fluorescence signals is a laborious and time-consuming task. An automated analysis of fluorescent signals circumvents user bias and time constraints. However, it requires to overcome several challenges, including correct estimation of fluorescence fluctuations at basal concentrations of messenger molecules, detection and extraction of events themselves, proper segmentation of neighboring events as well as tracking of propagating events. Moreover, event detection algorithms need to be sensitive enough to accurately capture localized and low amplitude events exhibiting a limited spatial extent. This thesis presents three novel algorithms, PBasE, CoRoDe and KalEve, for the automated analysis of fluorescence events, developed to overcome the aforementioned challenges. The algorithms are integrated into a graphical application called MSparkles, specifically designed for the analysis of fluorescence signals, developed in MATLAB. The capabilities of the algorithms are demonstrated by analyzing astroglial Ca2+ events, recorded in anesthetized and awake mice, visualized using genetically encoded Ca2+ indicators (GECIs) GCaMP3 as well as GCaMP5. The results were compared to those obtained by other software packages. In addition, the analysis of neuronal Na+ events recorded in acute brain slices using SBFI-AM serve to indicate the putatively broad application range of the presented algorithms. Finally, due to increasing evidence of the pivotal role of astrocytes in neurodegenerative diseases such as epilepsy, a metric to assess the synchronous occurrence of fluorescence events is introduced. In a proof-of-principle analysis, this metric is used to correlate astroglial Ca2+ events with EEG measurementsFluoreszenzfarbstoffe und genetisch kodierte Fluoreszenzindikatoren (GEFI) sind gängige Werkzeuge zur Visualisierung von Konzentrationsänderungen bestimmter Ionen und Botenmoleküle der intra- sowie interzellulären Kommunikation. Während Fluoreszenzfarbstoffe direkt in die Zielzellen eingebracht werden müssen und nur über einen begrenzten Zeitraum funktionieren, kann die Expression von GEFIs zell- und zeitspezifisch gesteuert werden, was darüber hinaus Langzeitanalysen in lebenden Organismen ermöglicht. Farbstoff- und GEFI-basierte Fluoreszenzfluktuationen, die mit Hilfe moderner bildgebender Verfahren aufgezeichnet werden, bilden die Grundlage für die Analyse physiologischer molekularer Kommunikation. Die Analyse einer großen Zahl komplexer Fluoreszenzsignale ist jedoch eine schwierige und zeitaufwändige Aufgabe. Eine automatisierte Analyse ist dagegen weniger zeitaufwändig und unabhängig von der Voreingenommenheit des Anwenders. Allerdings müssen hierzu mehrere Herausforderungen bewältigt werden. Unter anderem die korrekte Schätzung von Fluoreszenzschwankungen bei Basalkonzentrationen von Botenmolekülen, die Detektion und Extraktion von Signalen selbst, die korrekte Segmentierung benachbarter Signale sowie die Verfolgung sich ausbreitender Signale. Darüber hinaus müssen die Algorithmen zur Signalerkennung empfindlich genug sein, um lokalisierte Signale mit geringer Amplitude sowie begrenzter räumlicher Ausdehnung genau zu erfassen. In dieser Arbeit werden drei neue Algorithmen, PBasE, CoRoDe und KalEve, für die automatische Extraktion und Analyse von Fluoreszenzsignalen vorgestellt, die entwickelt wurden, um die oben genannten Herausforderungen zu bewältigen. Die Algorithmen sind in eine grafische Anwendung namens MSparkles integriert, die speziell für die Analyse von Fluoreszenzsignalen entwickelt und in MATLAB implementiert wurde. Die Fähigkeiten der Algorithmen werden anhand der Analyse astroglialer Ca2+-Signale demonstriert, die in narkotisierten sowie wachen Mäusen aufgezeichnet und mit den genetisch kodierten Ca2+-Indikatoren (GECIs) GCaMP3 und GCaMP5 visualisiert wurden. Erlangte Ergebnisse werden anschließend mit denen anderer Softwarepakete verglichen. Darüber hinaus dient die Analyse neuronaler Na+-Signale, die in akuten Hirnschnitten mit SBFI-AM aufgezeichnet wurden, dazu, den breiten Anwendungsbereich der Algorithmen aufzuzeigen. Zu guter Letzt wird aufgrund der zunehmenden Indizien auf die zentrale Rolle von Astrozyten bei neurodegenerativen Erkrankungen wie Epilepsie eine Metrik zur Bewertung des synchronen Auftretens fluoreszenter Signale eingeführt. In einer Proof-of-Principle-Analyse wird diese Metrik verwendet, um astrogliale Ca2+-Signale mit EEG-Messungen zu korrelieren

Carcinogenic oestrogens induce respiration deficiency mutation in yeast

In addition to hormonal activity, genetic darnage has been proposed as an important factor in oestrogen-mediated carcinogenesis. However, as short-term tests for oestrogens usually fail to show DNA mutations, lesions other than dassie nuclear DNA mutation have to be considered. Oestrogeninduced mitochondrial darnage was studied in the yeast Saccharomyces cerevisiae. Stilbene-type, but not steroidal, oestrogens were found to induce respiration-dcficient petite mutation. The effect was inversely correlated with cytotoxicity and required aromatic hydroxyl groups at the stilbene molecule. It only occurred under growth conditions and apparently was not due to the A TPase inhibitory qualities of stilbene oestrogens. Other studies have shown that petite mutation clones, which can be induced by a variety of substances, contain altered mitochondrial DNA. The mechanism of petite mutation induction might be important in tumorigenesis by also acting on nuclear DNA or facilitating carcinogenesis by disturbance of mitochondrial function

Perceptions of Caring and Nursing by Senior Level Baccalaureate Nursing Students from Thailand and the United States as Influenced by Curriculum Focus: A Descriptive, Comparative Study

The health care delivery system and its services are experiencing significant changes that affect nursing's core concept of caring. These changes are often complicated, influenced by the context of a particular environment, and are comprised of specific purposes and agendas aimed at meeting the healthcare needs of the consumer. Healthcare organizations are structures through which individuals cooperate systematically to conduct business. Business like as it may sound, "within the walls of the health care organization in all settings, profound human experiences happen every single day" (Koloroutis, 2004, p. 7) that strike to the essence of nursing, that of caring. Challenges unique to nursing must be addressed in this changing environment. It is appropriate, therefore, that the essential characteristic of caring within the profession of nursing and within all cultures be a focus of study. Nursing faculty have as their role to develop and implement curriculums that contribute to the development of the skills needed to prepare graduates for practice in an increasingly complex healthcare environment while still fostering the professional socialization of students into the values, principles, and beliefs of the profession. Evaluation of the effects of the curriculum in preparing students to practice in an environment aimed at healing and caring is encompassed within this role. In the process of curriculum change aimed at meeting societal health care needs, faculty continues to be challenged to monitor for gaps in the overall curriculum. In meeting the challenges for the future, curriculum models are being developed and implemented based on caring science. This study compared nursing schools that have incorporated a caring model curriculum with a systems model curriculum. Students from three schools in the Southeast or Midwest United States, and Thailand participated in the study. Senior level and entry level students provided their perceptions of caring using the Caring Factor Survey - Care Provider Version (CFS-CPV) and the Caring Factor Survey - Care for Self (CFS-CS) instruments. Demographic information was also collected. There were no statistically significant differences between schools having a caring curriculum model and a systems model. Significant positive correlations were found for CFS-Care Provider and Care for Self total scores; that is, those students who scored higher on the care provider instrument also scored higher on the care for self-instrument. Entry level students in Thailand scored higher than seniors from the Southeast and Midwest schools on the CFS-Care Provider and Care for Self instrument. Qualitative themes related to reasons motivating answering of the questions included: positive attitude or respect toward self-care, personal attributes, current intervening factors that decrease the ability to care for self, external factors contributing to self-care such as family, friends, and life experience, influence of faith, religion, and spirituality, personal philosophical statements, and lifestyle. While there was variability in the demographics, these did not have statistical significance on the study. The outcomes of the study have generated further questions for research and confirm the importance of focused study on the development of curricula, creation of courses consistent with the curriculum, implementation of learning strategies, and evaluation of outcomes in meeting the goal of sustaining nursing's value of caring as it relates to health of individuals and populations and across cultures