62 research outputs found
The Market for Television Advertising: Model and Evidence
We provide a model of television advertising based on an explicit characterization of an advertisement's contribution to an advertiser's profits that suggests that each program faces a downward sloping demand for its ad time. Hence Fournier and Martin's (1983) "law of one price" does not hold in our model. We study these contrasting arguments about television advertising by examining the pricing of broadcast network advertising. In conducting this empirical examination we encounter and solve a severe multicollinearity problem. We conclude that the evidence supports the advertising model presented in this paper and demonstrates segmentation between cable and broadcast viewers in the national television advertising market.broadcast, cable, market segmentation, multicollinearity,
Optimisation of a diamond nitrogen vacancy centre magnetometer for sensing of biological signals
Sensing of signals from biological processes, such as action potential
propagation in nerves, are essential for clinical diagnosis and basic
understanding of physiology. Sensing can be performed electrically by placing
sensor probes near or inside a living specimen or dissected tissue using well
established electrophysiology techniques. However, these electrical probe
techniques have poor spatial resolution and cannot easily access tissue deep
within a living subject, in particular within the brain. An alternative
approach is to detect the magnetic field induced by the passage of the
electrical signal, giving the equivalent readout without direct electrical
contact. Such measurements are performed today using bulky and expensive
superconducting sensors with poor spatial resolution. An alternative is to use
nitrogen vacancy (NV) centres in diamond that promise biocompatibilty and high
sensitivity without cryogenic cooling. In this work we present advances in
biomagnetometry using NV centres, demonstrating magnetic field sensitivity of
approximately 100 pT/ in the DC/low frequency range using a setup
designed for biological measurements. Biocompatibility of the setup with a
living sample (mouse brain slice) is studied and optimized, and we show work
toward sensitivity improvements using a pulsed magnetometry scheme. In addition
to the bulk magnetometry study, systematic artifacts in NV-ensemble widefield
fluorescence imaging are investigated
Optimisation of a diamond nitrogen vacancy centre magnetometer for sensing of biological signals
Sensing of signals from biological processes, such as action potential
propagation in nerves, are essential for clinical diagnosis and basic
understanding of physiology. Sensing can be performed electrically by placing
sensor probes near or inside a living specimen or dissected tissue using well
established electrophysiology techniques. However, these electrical probe
techniques have poor spatial resolution and cannot easily access tissue deep
within a living subject, in particular within the brain. An alternative
approach is to detect the magnetic field induced by the passage of the
electrical signal, giving the equivalent readout without direct electrical
contact. Such measurements are performed today using bulky and expensive
superconducting sensors with poor spatial resolution. An alternative is to use
nitrogen vacancy (NV) centres in diamond that promise biocompatibilty and high
sensitivity without cryogenic cooling. In this work we present advances in
biomagnetometry using NV centres, demonstrating magnetic field sensitivity of
approximately 100 pT/ in the DC/low frequency range using a setup
designed for biological measurements. Biocompatibility of the setup with a
living sample (mouse brain slice) is studied and optimized, and we show work
toward sensitivity improvements using a pulsed magnetometry scheme. In addition
to the bulk magnetometry study, systematic artifacts in NV-ensemble widefield
fluorescence imaging are investigated
Optimization of a Diamond Nitrogen Vacancy Centre Magnetometer for Sensing of Biological Signals
Sensing of signals from biological processes, such as action potential propagation
in nerves, are essential for clinical diagnosis and basic understanding of physiology.
Sensing can be performed electrically by placing sensor probes near or inside a
living specimen or dissected tissue using well-established electrophysiology techniques.
However, these electrical probe techniques have poor spatial resolution and cannot easily
access tissue deep within a living subject, in particular within the brain. An alternative
approach is to detect the magnetic field induced by the passage of the electrical signal,
giving the equivalent readout without direct electrical contact. Such measurements are
performed today using bulky and expensive superconducting sensors with poor spatial
resolution. An alternative is to use nitrogen vacancy (NV) centers in diamond that promise
biocompatibilty and high sensitivity without cryogenic cooling. In this work we present
advances in biomagnetometry using NV centers, demonstrating magnetic field sensitivity
of ∼100 pT/√Hz in the DC/low frequency range using a setup designed for biological
measurements. Biocompatibility of the setup with a living sample (mouse brain slice)
is studied and optimized, and we show work toward sensitivity improvements using a
pulsed magnetometry scheme. In addition to the bulk magnetometry study, systematic
artifacts in NV-ensemble widefield fluorescence imaging are investigated
Seed size relationships in kleingrass, Panicum coloratum L
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Not availabl
Free Cash Flow and Stockholder Gains in Going Private Transactions Revisited
Lehn and Poulsen (1983) are frequently cited as providing evidence supporting the applicability of Jensen's (1986) 'free cash flow' hypothesis to going private transactions. The paper re-examines the Lehn and Poulsen data and arrives at different inferences about the applicability of Jensen's 'free cash flow' hypothesis to their sample. First, I find that neither the level of a public corporation's pre-transaction 'free cash flows' nor its prior growth rate are significant determinants of its probability of going private. Second, I find a firm's size and its potential for reducing taxes, rather than its pre-transaction level of 'free cash flows', are significant determinants of the premium paid to take it private. And finally, comparing their 1980-1983 subsample to their 1984-1987 subsample reveals that firms that went private during the 1984-1987 period demonstrate a greater incidence of prior takeover interest, lower prior tax burdens, and slower prior growth than firms that went private during the 1980-1983 period: all of which supports Kaplan and Stein's (1993) overheated buyout market hypothesis. Copyright Blackwell Publishers Ltd 1998.
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