Feasibility of UV lasing without inversion in mercury vapor

We investigate the feasibility of UV lasing without inversion at a wavelength of $253.7$ nm utilizing interacting dark resonances in mercury vapor. Our theoretical analysis starts with radiation damped optical Bloch equations for all relevant 13 atomic levels. These master equations are generalized by considering technical phase noise of the driving lasers. From the Doppler broadened complex susceptibility we obtain the stationary output power from semiclassical laser theory. The finite overlap of the driving Gaussian laser beams defines an ellipsoidal inhomogeneous gain distribution. Therefore, we evaluate the intra-cavity field inside a ring laser self-consistently with Fourier optics. This analysis confirms the feasibility of UV lasing and reveals its dependence on experimental parameters.Comment: changes were made according to reviewer comments (accepted for publication in JOSA B

Cell polarity under extreme morphological conditions

Cell polarity is an important phenomenon in a multitude of cellular and developmental processes. The cellular contexts that polarity occurs in include a wide array of morphological properties such as size, shape, and growth. An important, conserved system of cell polarity depends on the intracellular localisation of proteins that act as diffusive molecular switches. Since the localisation of these proteins depends on their reactive and diffusive properties, cell size and growth may alter polarity induced by localisation. My work contributes extensive analyses of an established protein localisation model under extreme morphological conditions such as extremely small and rapidly growing cells. My work also uncovers non-trivial, biologically relevant behaviour caused by the inclusion of these morphological properties and further discusses the mechanisms underlying the observed behaviour. In addition, I contribute and discuss a novel computational tool that can continue to aid the research community in understanding cell polarity under extreme morphological conditions

Territorial behaviour in certain horned ungulates, with special reference to the examples of Thomson's and Grant's Gazelles

An attempt has been made to distinguish between action area, home range, and territory in the Bovidae. The establishing of subjective boundaries is considered to be the most important criterion of territoriality. The existence of such boundaries becomes evident from certain behavioural symptoms; “defence” or better, localized dominance which may lead to intolerance, is one of them.Not all bovids are territorial. Within the territorial species, there seem to be at least two types: (a) The animals, usually in pairs, may, under favourable conditions, stay in their territories permanently; (b) Only the males are territorial and stay in temporary territories, usually for several weeks or months. This last type is obviously more common in horned ungulates than the first one. Within this second type (b), there are species-specific differences. For example, in Grant's gazelle (Gazella granti), under certain environmental conditions, this type of territoriality is combined with harem behaviour, but in the co-inhabiting Thomson's gazelle (Gazella thomsoni), the females roam through the territories of the males and stay together with the same buck only for a few hours per day.Even within one and the same species, there can be variations, apparently linked with differences in environmental conditions. This is discussed, using the examples of the Uganda kob (Adenota kobj, the wildebeest (Connochaetes taurinus), and Grant's gazelle. Finally, there can be differences in the territorial behaviour of the same individual according to the phases of territoriality (beginning, peak, end) which is shown by the example of Thomson's gazelle

Clean Up Techniques Used for Coastal Oil Spills: An Analysis of Spills Occurring in Santa Barbara, California, Prince William Sound, Alaska, the Sea Of Japan, and the Gulf Coast

An analysis of four spills occurring within the last 50 years to see the progression in clean up techniques used for coastal oil spills. The Santa Barbara, California Oil Spill of 1969, the Exxon Valdez Oil Spill of 1989 occurring in Prince William Sound, Alaska, the Nakhodka Oil Spill of 1997 occurring in the Sea of Japan, and the Deep Water Horizon Oil spill of 2010 occurring in the Gulf of Mexico, are analyzed. The different types of oil, the composition of oil, and the variables that effect spilled oil’s movement, are provided. Oil spill response planning and preparation are revealed, lessons learned from past spills are exhibited, long term and short term environmental trade-offs are compared, and historical outcomes are demonstrated throughout this research

Actigraphy in agitated patients with dementia : Monitoring treatment outcomes

Especially in pharmacotherapeutic research, a variety of methods to monitor behavioural and psychological symptoms of dementia (BPSD) are currently being discussed. To date, the most frequently used of these are clinical scales, which, however, are subjective and highly dependent on personnel resources. In our study, we tested the usefulness of actigraphy as a more direct and objective way to measure day-night rhythm disturbances and agitated behaviour.After a baseline assessment, 24 patients with probable dementia of the Alzheimer type (NINCDS-ADRDA) and agitated behaviour received either 3 mg melatonin (n=7), 2.5 mg dronabinol (n=7), or placebo (n=10) for two weeks. In addition, 10 young and 10 elderly healthy subjects were examined as a control group. Motor activity levels were assessed using an actigraph worn continuously on the wrist of the non-dominant hand. At the beginning and the end of the study, patients' Neuropsychiatric Inventory (NPI) scores were also assessed.In the verum group, actigraphic nocturnal activity (P=0.001), NPI total score (P=0.043), and NPI agitation subscale score (P=0.032) showed significant reductions compared to baseline. The treatment-baseline ratio of nocturnal activity (P=0.021) and treatment-baseline difference of the nocturnal portion of 24 h activity (P=0.012) were reduced. Patients' baseline activity levels were similar to those seen in healthy elderly subjects. Younger healthy subjects exhibited higher motor activity even at night. There was no correlation between actigraphy and NPI.Both actigraphic measures and the gold standard clinical scale were able to distinguish between the verum and placebo groups. However, because they did not correlate with each other, they clearly represent different aspects of BPSD, each of which reacts differently to therapy. As a result, actigraphy may well come to play an important role in monitoring treatment success in BPSD

Fatal lymphoproliferation and acute monocytic leukemia-like disease following infectious mononucleosis in the elderly

Three elderly patients are reported, in whom serologically confirmed recent infectious mononucleosis is followed by fatal lymphoproliferation (case 1), by acute monocytic leukemia (case 2), and by acute probably monocytic leukemia (case 3)

Extracting high fidelity quantum computer hardware from random systems

An overview of current status and prospects of the development of quantum computer hardware based on inorganic crystals doped with rare-earth ions is presented. Major parts of the experimental work in this area has been done in two places, Canberra, Australia and Lund, Sweden, and the present description follows more closely the Lund work. Techniques will be described that include optimal filtering of the initially inhomogeneously broadened profile down to well separated and narrow ensembles, as well as the use of advanced pulse-shaping in order to achieve robust arbitrary single-qubit operations with fidelities above 90%, as characterized by quantum state tomography. It is expected that full scalability of these systems will require the ability to determine the state of single rare-earth ions. It has been proposed that this can be done using special readout ions doped into the crystal and an update is given on the work to find and characterize such ions. Finally, a few aspects on the possibilities for remote entanglement of ions in separate rare-earth-ion-doped crystals are considered.Comment: 19 pages, 9 figures. Written for The Proceedings of the Nobelsymposium on qubits for future quantum computers, Gothenburg, May-0

Reversibility in the Extended Measurement-based Quantum Computation

When applied on some particular quantum entangled states, measurements are universal for quantum computing. In particular, despite the fondamental probabilistic evolution of quantum measurements, any unitary evolution can be simulated by a measurement-based quantum computer (MBQC). We consider the extended version of the MBQC where each measurement can occur not only in the (X,Y)-plane of the Bloch sphere but also in the (X,Z)- and (Y,Z)-planes. The existence of a gflow in the underlying graph of the computation is a necessary and sufficient condition for a certain kind of determinism. We extend the focused gflow (a gflow in a particular normal form) defined for the (X,Y)-plane to the extended case, and we provide necessary and sufficient conditions for the existence of such normal forms