149 research outputs found
Hysteresis in West German Unemployment Reconsidered
The view that high unemployment in West Germany and other European countries is caused by a path dependence effect - or "hysteresis" effect - is quite popular among economists. However, because of an identification problem, much of the empirical evidence for this hypothesis is not fu lly convincing. This paper suggests a testing procedure that overcomes this problem. It is argued that in a cointegration framework it is reasonable to define hysteresis as the absence of weak exogeneity of the explanatory variables. Building on a cointeg ration model of the employment rate in West Germany, I find only weak evidence for hysteresis.Cointegration, hysteresis, trade unions, unemployment
Regulation and Internet Access in Germany
We explain the recent events in the German market for online access using a model of a regulated monopoly renting phone lines to retailers. Retailers offer either a linear or a flat tariff to consumers. Consumer heterogeneity leads to adverse selectiion. We show why market entry for flatrate firms is difficult under a linear wholesale tariff. With both a linear and a flat wholesale tariff the consumer market shows a mixture of tariffs as well. When marginal costs are zero it is optimal to have a wholesale flatrate only. However, marginal moves towards this equilibrium are not always welfare improving.Internet, flatrate, adverse selection
The Minimum Inflation Rate for Euroland
As a result of the Balassa effect relative prices change rapidly between and within the euro countries. Thus it is impossible to find a common monetary policy that will result in price stability in all countries. Based on empirical estimates of the Balassa model, the paper calculates a minimum aggregate inflation rate which is compatible with the requirement that no country face a deflation. This minimum aggeragate inflation rate is 0.94% in the euro-11 countries and 1.13% in an extended Europe which incorporates the east European countries.Inflation target, Balassa-Samuelson effect, ECB
Decisions on Seasonal Unit Roots
Decisions on the presence of seasonal unit roots in economic time series are commonly taken on the basis of statistical hypothesis tests. Some of these tests have absence of unit roots as the null hypothesis, while others use unit roots as their null. Following a suggestion by Hylleberg (1995) to combine such tests in order to reach a clearer conclusion, we evaluate the merits of such test combinations on the basis of a Bayesian decision setup. We find that the potential gains over a pure application of the most common test due to Hylleberg et al. (1990) are small.
NMR Studies on the Temperature-Dependent Dynamics of Confined Water
We use H NMR to study the rotational motion of supercooled water in
silica pores of various diameters, specifically, in the MCM-41 materials C10,
C12, and C14. Combination of spin-lattice relaxation, line-shape, and
stimulated-echo analyses allows us to determine correlation times in very broad
time and temperature ranges. For the studied pore diameters, 2.1-2.9 nm, we
find two crossovers in the temperature-dependent correlation times of liquid
water upon cooling. At 220-230 K, a first kink in the temperature dependence is
accompanied by a solidification of a fraction of the confined water, implying
that the observed crossover is due to a change from bulk-like to
interface-dominated water dynamics, rather than to a liquid-liquid phase
transition. Moreover, the results provide evidence that process-like
dynamics is probed above the crossover temperature, whereas
process-like dynamics is observed below. At 180-190 K, we find a second change
of the temperature dependence, which resembles that reported for the
process of supercooled liquids during the glass transition, suggesting a value
of K for interface-affected liquid water. In the
high-temperature range, K, the temperature dependence of water
reorientation is weaker in the smaller C10 pores than in the larger C12 and C14
pores, where it is more bulk-like, indicating a significant effect of the
silica confinement on the process of water in the former 2.1 nm
confinement. By contrast, the temperature dependence of water reorientation is
largely independent of the confinement size and described by an Arrhenius law
with an activation energy of eV in the low-temperature
range, K, revealing that the confinement size plays a minor role
for the process of water.Comment: 12 pages, 9 figure
The Minimum Inflation Rate for Euroland
As a result of the Balassa effect relative prices change rapidly between and within the euro countries. Thus it is impossible to find a common monetary policy that will result in price stability in all countries. Based on empirical estimates of the Balassa model, the paper calculates a minimum aggregate inflation rate which is compatible with the requirement that no country face a deflation. This minimum aggeragate inflation rate is 0.94% in the euro-11 countries and 1.13% in an extended Europe which incorporates the east European countries.
NMR studies on the temperature-dependent dynamics of confined water
We use ²H NMR to study the rotational motion of supercooled water in silica pores of various diameters,
specifically, in the MCM-41 materials C10, C12, and C14. Combination of spin–lattice relaxation, lineshape,
and stimulated-echo analyses allows us to determine correlation times in very broad time and
temperature ranges. For the studied pore diameters, 2.1–2.9 nm, we find two crossovers in the
temperature-dependent correlation times of liquid water upon cooling. At 220–230 K, a first kink in the
temperature dependence is accompanied by a solidification of a fraction of the confined water, implying
that the observed crossover is due to a change from bulk-like to interface-dominated water dynamics,
rather than to a liquid–liquid phase transition. Moreover, the results provide evidence that α process-like
dynamics is probed above the crossover temperature, whereas β process-like dynamics is observed
below. At 180–190 K, we find a second change of the temperature dependence, which resembles
that reported for the β process of supercooled liquids during the glass transition, suggesting a value of
Tg ≈ 185 K for interface-affected liquid water. In the high-temperature range, T > 225 K, the temperature
dependence of water reorientation is weaker in the smaller C10 pores than in the larger C12 and
C14 pores, where it is more bulk-like, indicating a significant effect of the silica confinement on the α
process of water in the former 2.1 nm confinement. By contrast, the temperature dependence of water
reorientation is largely independent of the confinement size and described by an Arrhenius law with an
activation energy of Ea ≈ 0.5 eV in the low-temperature range, T < 180 K, revealing that the confinement
size plays a minor role for the β process of water
Structural Features Underlying Raloxifene’s Biophysical Interaction with Bone Matrix
Raloxifene, a selective estrogen receptor modulator (SERM), reduces fracture risk at least in part by improving the mechanical properties of bone in a cell- and estrogen receptor-independent manner. In this study, we determined that raloxifene directly interacts with the bone tissue. Through the use of multiple and complementary biophysical techniques including nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR), we show that raloxifene interacts specifically with the organic component or the organic/mineral composite, and not with hydroxyapatite. Structure–activity studies reveal that the basic side chain of raloxifene is an instrumental determinant in the interaction with bone. Thus, truncation of portions of the side chain reduces bone binding and also diminishes the increase in mechanical properties. Our results support a model wherein the piperidine interacts with bone matrix through electrostatic interactions with the piperidine nitrogen and through hydrophobic interactions (van der Waals) with the aliphatic groups in the side chain and the benzothiophene core. Furthermore, in silico prediction of the potential binding sites on the surface of collagen revealed the presence of a groove with sufficient space to accommodate raloxifene analogs. The hydroxyl groups on the benzothiophene nucleus, which are necessary for binding of SERMs to the estrogen receptor, are not required for binding to the bone surface, but mediate a more robust binding of the compound to the bone powder. In conclusion, we report herein a novel property of raloxifene analogs that allows them to interact with the bone tissue through potential contacts with the organic matrix and in particular collagen
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