4,121 research outputs found
Debate: Should the elderly receive thrombolytic therapy or primary angioplasty?
Thrombolysis and primary angioplasty are both recommended reperfusion strategies for elderly patients presenting with myocardial infarction (MI). Primary angioplasty is most beneficial in high-risk patients. While the elderly have a high absolute risk of dying or developing complications after MI, they also have an increased risk of intracranial haemorrhage if they are given thrombolytic therapy. It could therefore be reasonably argued that primary angioplasty is the reperfusion strategy of choice in the elderly. However, primary angioplasty has not been shown to have a greater relative benefit than thrombolytic therapy in the elderly. Recent data from the Fibrinolytic Therapy Trialists' (FTT) Collaborative Group show that thrombolytic therapy significantly reduces mortality compared with control treatment in patients over 75 years of age presenting within 12 h of symptom onset, with ST-segment elevation or bundle branch block. Future advances in adjunctive therapies may improve myocyte perfusion and hence the outcomes achieved by both invasive and noninvasive reperfusion strategies. Better thrombolytic regimens incorporating adjunctive agents such as bivalirudin may reduce the risk of intracranial haemorrhage. Few hospitals can provide a 24-h primary angioplasty service with door-to-balloon times consistently less than 90 min, and thrombolytic therapy is therefore a far more practical option in most instances
Laser frequency locking by direct measurement of detuning
We present a new method of laser frequency locking in which the feedback
signal is directly proportional to the detuning from an atomic transition, even
at detunings many times the natural linewidth of the transition. Our method is
a form of sub-Doppler polarization spectroscopy, based on measuring two Stokes
parameters ( and ) of light transmitted through a vapor cell. This
extends the linear capture range of the lock loop by up to an order of
magnitude and provides equivalent or improved frequency discrimination as other
commonly used locking techniques.Comment: 4 pages, 4 figures Revte
Measuring Entangled Qutrits and Their Use for Quantum Bit Commitment
We produce and holographically measure entangled qudits encoded in transverse
spatial modes of single photons. With the novel use of a quantum state
tomography method that only requires two-state superpositions, we achieve the
most complete characterisation of entangled qutrits to date. Ideally, entangled
qutrits provide better security than qubits in quantum bit-commitment: we model
the sensitivity of this to mixture and show experimentally and theoretically
that qutrits with even a small amount of decoherence cannot offer increased
security over qubits.Comment: Paper updated to match published version; 5 pages, 4 figures, images
have been included at slightly lower quality for the archiv
Telemetric Observations of Foraging Ozark Big-Eared Bats in Arkansas
Ozark big-eared bat (Corynorhinus townsendii ingens) foraging activities were studied during 1995 in Marion County, Arkansas. Adult bats were equipped with radiotransmitters and tracked during June and July. Foraging activities were generally within 1 kilometer (km) of the roost cave. Male bats ranged farther than females with the exception of one female that flew 2.5 km into a different watershed. Male big-eared bats and northern long-eared bats (Myotis septentrionalis) were also found within the maternity colony
Frequency Locking by Analysis of Orthogonal Modes
We describe a method for frequency locking a laser and a cavity. Orthogonal modes from the laser are incident on a cavity such that only one mode is resonant at the desired frequency. The polarisation or spatial phase distribution of the light reflected from the cavity is analysed, yielding the phase between the modes - this is the locking signal. We compare this method with other locking techniques, and show this to be a natural progression from these. Simulations are presented for applications of interest, e.g., gravity wave interferometry (an empty cavity) and optical frequency conversion (a polarisation dependent cavity)
Capital Fixity and Mobility in Response to the 2008-09 Crisis: Variegated Neoliberalism in Mexico and Turkey
The article examines the 2008-9 crisis responses in Mexico and Turkey as examples of variegated neoliberalism. The simultaneous interests of corporations and banks relative to the national fixing of capital and their mobility in the form of global investment heavily influenced each state authorityâs policy responses to the crisis at the expense of the interests of the poor, workers, and peasantry. Rather than pitching this as either evidence of persistent national differentiation or some Keynesian state resurgence, we argue from a historical materialist geographical framework that the responses of capital and state authorities in Mexico and Turkey actively constitute and reconstitute the global parameters of market regulatory design and neoliberal class rule through each stateâs distinct domestic policy formation and crisis management processes. While differing in specific content the form of Mexico and Turkeyâs state responses to the crisis ensured continuity in their foregoing neoliberal strategies of development and capital accumulation, most notably in the continued oppression of workers. That is, the prevailing strategy of accumulation continues to be variegated neoliberalism
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