285 research outputs found
Vibrational Satellites of CS, CS, and CS: Microwave Spectral Taxonomy as a Stepping Stone to the Millimeter-Wave Band
We present a microwave spectral taxonomy study of several hydrocarbon/CS
discharge mixtures in which more than 60 distinct chemical species, their more
abundant isotopic species, and/or their vibrationally excited states were
detected using chirped-pulse and cavity Fourier-transform microwave
spectroscopies. Taken together, in excess of 85 unique variants were detected,
including several new isotopic species and more than 25 new vibrationally
excited states of CS, CS, and CS, which have been assigned on the
basis of published vibration-rotation interaction constants for CS, or
newly calculated ones for CS and CS. On the basis of these precise,
low-frequency measurements, several vibrationally exited states of CS and
CS were subsequently identified in archival millimeter-wave data in the
253--280 GHz frequency range, ultimately providing highly accurate catalogs for
astronomical searches. As part of this work, formation pathways of the two
smaller carbon-sulfur chains were investigated using C isotopic
spectroscopy, as was their vibrational excitation. The present study
illustrates the utility of microwave spectral taxonomy as a tool for complex
mixture analysis, and as a powerful and convenient `stepping stone' to higher
frequency measurements in the millimeter and submillimeter bands.Comment: Accepted in PCC
Digitalisering af universitetets prøveformer
Om temaet: Digitalisering af universitetets prøveformer
ICTs and the concept and practice of internationalization of higher education
In this article, we will discuss the potential of ICTs in terms of developing the concept and practice of internationalisation of higher education. Based on a number of Danish and international cases, it will be argued that ICTs are being used as tools in the process of developing the concept and prac-tice of internationalisation of higher education. Why this is not happening to a broader extent is discussed and it is suggested that a clear, strategic anchoring of such efforts, including the proper support services, the parti-cipation and ownership of faculty, staff and students, and clear financial prospects may be necessary in order to successfully apply ICTs for internationalisation purposes on a broader scale. Finally, it is highlighted that more research, studies and documentation of practice in this area, not least in a Danish setting, would be beneficial to develop and broaden the concept and practice of internationalisation
A Laboratory Study of C_3H^+ and the C_3H Radical in Three New Vibrationally Excited ^2Σ States Using a Pin-Hole Nozzle Discharge Source
Rotational lines of the positive molecular ion C_3H^+ and of the neutral C_3H radical in three new vibrationally excited states with ^2Σ symmetry have been detected in a supersonic molecular beam in the centimeter-wave band. The fundamental rotational line of the ion is quite weak, but is observed with similar intensity in a dc discharge through several different hydrocarbon gases when helium is the buffer gas. Under these conditions, the fractional abundance of C_3H^+ relative to C_3H is estimated to be of order 10^(−4), i.e., toward the lower end of the ratio (10^(−3)–10^(−4)) found for protonated ions using the same discharge nozzle. For each new ^2Σ state of the C_3H radical, spectroscopic constants, including those describing hydrogen hyperfine structure, have been determined to high precision. Lines of one ^2Σ state (B = 11271 MHz) are particularly intense in our molecular beam; for this state and a second one (B = 11306 MHz), millimeter-wave transitions have also been observed between 180 and 340 GHz using a long path dc glow absorption spectrometer. On the basis of intensity measurements with this spectrometer, the inferred rotation–vibration constant α, and theoretical calculations, the state with B = 11271 MHz is tentatively assigned to the ν_5 bending mode, predicted to lie ~300 cm^(−1) above ground
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Hypoxia Activates a Ca-Permeable Cation Conductance Sensitive to Carbon Monoxide and to GsMTx-4 in Human and Mouse Sickle Erythrocytes
Background: Deoxygenation of sickle erythrocytes activates a cation permeability of unknown molecular identity (Psickle), leading to elevated intracellular [Ca2+] ([Ca2+]i) and subsequent activation of KCa 3.1. The resulting erythrocyte volume decrease elevates intracellular hemoglobin S (HbSS) concentration, accelerates deoxygenation-induced HbSS polymerization, and increases the likelihood of cell sickling. Deoxygenation-induced currents sharing some properties of Psickle have been recorded from sickle erythrocytes in whole cell configuration. Methodology/Principal Findings: We now show by cell-attached and nystatin-permeabilized patch clamp recording from sickle erythrocytes of mouse and human that deoxygenation reversibly activates a Ca2+- and cation-permeable conductance sensitive to inhibition by Grammastola spatulata mechanotoxin-4 (GsMTx-4; 1 µM), dipyridamole (100 µM), DIDS (100 µM), and carbon monoxide (25 ppm pretreatment). Deoxygenation also elevates sickle erythrocyte [Ca2+]i, in a manner similarly inhibited by GsMTx-4 and by carbon monoxide. Normal human and mouse erythrocytes do not exhibit these responses to deoxygenation. Deoxygenation-induced elevation of [Ca2+]i in mouse sickle erythrocytes did not require KCa3.1 activity. Conclusions/Significance: The electrophysiological and fluorimetric data provide compelling evidence in sickle erythrocytes of mouse and human for a deoxygenation-induced, reversible, Ca2+-permeable cation conductance blocked by inhibition of HbSS polymerization and by an inhibitor of strctch-activated cation channels. This cation permeability pathway is likely an important source of intracellular Ca2+ for pathologic activation of KCa3.1 in sickle erythrocytes. Blockade of this pathway represents a novel therapeutic approach for treatment of sickle disease
The global and regional burden of genital ulcer disease due to herpes simplex virus:a natural history modelling study
Adrift in time:The subjective experience of circadian challenge during COVID-19 amongst people with mood disorders
Social distancing/lockdown policies during the coronavirus (COVID-19) pandemic may alter social rhythms of people through imposition of restrictions on normal daily activities. This may in turn challenge circadian function, particularly in people with mood disorders. Although objective data describing the relationship between circadian disturbances and mood disorders exist, data regarding the subjective experience of circadian challenge is sparse, and its association with mood symptoms is unclear. The present qualitative study was one component of a mixed-methods multi-national project, which took advantage of widespread disruption to daily routines due to Government COVID-related lockdowns during 2020. The Behavior Emotion and Timing during COVID-19 (BEATCOVID) survey study included three open questions generating qualitative data on participants' subjective experience of social disruption due to social distancing/lockdown policies, two of which asked about the barriers and opportunities for stabilizing routines. Responses were coded and analyzed using Thematic Analysis. A total of N = 997 participants responded to at least one of the free-text questions. Four themes were identified: 1) loss of daily timed activities, 2) role of social interaction, 3) altered time perception and 4) disruption to motivation and associated psychological effects. Themes were organized into a provisional heuristic map, generating hypotheses for future research centered on the new concept of 'psychological drift.
Neurobiological and behavioral mechanisms of circadian rhythm disruption in bipolar disorder: A critical multi‐disciplinary literature review and agenda for future research from the ISBD task force on chronobiology
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