Oxygen consumption

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Is Oxygen Consumption of Surviving Tissues Determined by the Oxygen Tension of the Suspension Medium? 

Is Oxygen Consumption of Surviving Tissues Determined by the Oxygen Tension of the Suspension Medium? 

Oxygen uptake was measured at least for four hours. Readings of oxygen uptake were taken with 5 min intervals. Oxygen consumption was cal­ culated with a computer programme at the G.M.D. Bonn. The results are given as mean values for 30 min periods; the first 30 min period is omitted from evaluation as explained formerly [2 1 ]. For technical reasons in most experiments 0 2-tension could be measured for 3 h only. The simultaneous measurement of oxygen uptake and oxygen tension of the suspension medium was performed 3 to 8 times with each of the combinations of oxygen con­ centration in the gas phase and shaking frequency. Altogether 272 simultaneous measurements were per­ formed. After the high reproducibility of the oxy­ gen tension in the suspension medium had been established it was sufficient to measure oxygen up­ take only.
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The Developmental Rate and Oxygen Consumption of Snail Eggs at Various Temperatures 

The Developmental Rate and Oxygen Consumption of Snail Eggs at Various Temperatures 

using lettuce as food. When eggs were desired for ex­ periments, small sheets of plastic were laid on the sur­ face of the water. By preference the snails lay their eggs on these. Eggs were collected over 2 — 4 hour periods. Constant temperature incubations were made in waterbaths at the indicated temperatures, several thousand eggs in replicates being used at each tem­ perature. Oxygen consumption determinations were made by standard W a r b u r g manometry using several hundred eggs per 15 ml. vessel (at the lowest temperatures up to 1000 eggs were used per vessel). To avoid possible complications from circadian rhythms, oxygen consumption measurements were made over a two-hour period always at the same time of day (in the 18 — 22 hour period).
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Cellular oxygen consumption, ROS production and ROS defense in two different size-classes of Amazonian obligate air-breathing fish (Arapaima gigas)

Cellular oxygen consumption, ROS production and ROS defense in two different size-classes of Amazonian obligate air-breathing fish (Arapaima gigas)

caused a significant reduction in oxygen uptake. In gill, kidney, and ABO cells of larger fish, oxygen uptake was reduced by more than 60%, in gill and ABO of small fish it was even reduced by more than 70% of the value recorded for CI + CII in the presence of ADP, and in kidney cells to less than 10%. During subsequent normoxic recovery, oxygen uptake returned to the level recorded prior to hypoxia, reaching between 88% and 130% of the value recorded for CI + CII in the presence of ADP. None of these values was significantly different from the oxygen consumption measured prior to the hypoxic bout. In all three cell types, hyperoxia had no significant effect on the rate of oxygen uptake, but during recovery from hyperoxia, in all tissues oxygen uptake initially was reduced as compared to the normoxic values recorded for CI + CII in the presence of ADP ( Fig 2A–2C ), and in gill and ABO cells this decrease was espe- cially pronounced. Oxygen uptake based on the activity of complex IV was determined at the end of the measurements by addition of TMPD, and in all tissues by far exceeded oxygen con- sumption rates recorded before. S1 Table lists statistically significant differences in the oxygen uptake recorded during the different steps in the protocol, based on three-way ANOVA.
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Impacts of Accumulated Particulate Organic Matter on Oxygen Consumption and Organic Micro-Pollutant Elimination in Bank Filtration and Soil Aquifer Treatment

Impacts of Accumulated Particulate Organic Matter on Oxygen Consumption and Organic Micro-Pollutant Elimination in Bank Filtration and Soil Aquifer Treatment

Although the cores were only approximately 180 mm in height, all parallel cores showed a high or even complete oxygen consumption during the first 150 days, as displayed in Figure 2 . The accumulated POC even in the lower sand layer (cores S1 and S2) was capable of influencing the redox conditions substantially, despite the low carbon content of only 0.04%. The cleaning of the SAT basin by removing the top colmation layer therefore was not sufficient to recover the oxygen supply to lower layers completely. From day 200 onwards, the oxygen concentrations in the SAT column effluents increased significantly. The cores C1 and C2 with residuals of the colmation layer revealed higher oxygen consumptions during the complete experiment duration compared to the parallel cores S1 and S2 containing the subjacent SAT sand. The higher carbon content in the colmation layer (as given in Table 1 ) provides a reasonable explanation. Thus, the accumulation of POC in the SAT basin affects the redox-conditions during treatment.
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Does enhanced footwear comfort affect oxygen consumption and running biomechanics?

Does enhanced footwear comfort affect oxygen consumption and running biomechanics?

Comfort as an essential parameter for running footwear is gaining importance in footwear research and development, and has also been proposed to decrease injury rate and improve metabolic demand in the paradigm of the comfort filter. The aims of this study were to determine differences in oxygen consumption and biomechanical variables associated with lower extremity injuries in response to running shoes of differing comfort. Fifteen male runners attended two testing sessions including an incremental lactate threshold test, a comfort assessment and treadmill running trials for the biomechanical and physiological measurements. Statistical analyses were performed on oxygen consumption, spatio-temporal variables including foot-ground angle and coupling angle variability of 12 couplings in five stride phases. No decrease in oxygen consumption was found in the most preferred shoe condition. Investigation of potential biomechanical contributors to changes in metabolic demands revealed differences in the stride rate between the most and least preferred condition. In coupling angle variability analyses, only one coupling (ankle dorsiflexion/plantarflexion to knee varus/valgus) yielded a significant difference between conditions in the phase including the touch down. Based on the findings of this study, previous suggestions regarding positive effects of enhanced footwear comfort during running cannot be supported – neither on economy nor on injury prevention perspective. However, a prospective study of lower extremity injury combined with measurements of biomechanical and physiological variables seems to be required for a definite support or contradiction of the comfort filter.
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Oxygen Consumption by Liver and Kidney Slices of Uromastix Hardwickii 

Oxygen Consumption by Liver and Kidney Slices of Uromastix Hardwickii 

concerned mainly with the oxygen consumption and carbohydrate oxidation by the liver and kidney slices of Uromastix hardwickii. Animals: The lizards, Uromastix hardwickii were collect[r]

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Increased Oxygen Consumption of Ehrlich Ascites Tumor Cells Following Serial Cultivation in Media with Increased (Hypertonic) NaCl Content 

Increased Oxygen Consumption of Ehrlich Ascites Tumor Cells Following Serial Cultivation in Media with Increased (Hypertonic) NaCl Content 

Ehrlich ascites tumor cells adapted to serial cultivation in vitro in media with increased NaCl content ("high-salt"-tolerant cells) exhibit — in comparison with cells cultivate[r]

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Online monitoring of dissolved oxygen tension in microtiter plates based on infrared fluorescent oxygen-sensitive nanoparticles

Online monitoring of dissolved oxygen tension in microtiter plates based on infrared fluorescent oxygen-sensitive nanoparticles

Oxygen‑unlimited cultivation of G. oxydans Δupp In Fig.  4 cultivations of G. oxydans Δupp in unbuffered complex mannitol medium with and without dispersed oxygen-sensitive nanoparticles are compared with each other. Since the DOT values were above 0  % and no maximal oxygen transfer capacity plateau [ 22 , 23 ] could be observed in the OTR curves, no oxygen-limitation occurred during the whole cultivations. The minimum of the DOT of 9.8 % air saturation in the MTP as well as the maximum of the OTR of 38.9 mmol L −1  h −1 in the shake flask were reached exactly at the same time after 7  h. The rapid decrease of the DOT in the MTP and simul- taneously the increase in OTR in the shake flask were caused by the oxygen consumption during exponential growth of G. oxydans Δupp and the mannitol oxidation to fructose [ 25 ]. To calculate the OTR in the MTP from the DOT the k L a value of the MTP is needed. According to the performed parameter estimation of the k L a value the best approximation between OTR in MTP and shake flask was obtained with a k L a value of 186 h −1 . With that k L a value the calculated OTR curve of the MTP perfectly coincides with the OTR curve of the shake flask during the whole cultivation (Fig.  4 a). Likewise, the trends of the scattered light curves of the cultivations in the MTP with and without dispersed oxygen sensitive nanoparticles are comparable to the propagation of the OTR curves (Fig.  4 b). Until the end of the exponential growth (7 h) the scattered light intensity increased exponentially. Sub- sequently, the bacteria entered into the stationary phase at about 8 h which was indicated by the scattered light signal levelling off on a plateau till the end of the experi- ment. In agreement with that trend the DOT increases and the OTR decreases.
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Chloride Requirement for Oxygen Evolution in Photosynthesis 

Chloride Requirement for Oxygen Evolution in Photosynthesis 

The role of chloride in photosynthetic oxygen evolution was reinvestigated by determining the effect of this ion on photochemical reactions of chloroplasts in which oxygen either is or is not produced. The chloroplasts used were isolated from normal spinach leaves. The level of chloride in the reaction mixture was controlled by washing the isolated chloroplasts and by avoiding a chloride contamination from the water and chemicals used. Chloride was found to be essential for each of the photochemical reactions of chloroplasts in which oxygen is produced. These included (a) photo­ reduction of TPN, (b) photophosphorylation of the noncyclic type in which TPN or ferricyanide reduction is coupled with ATP formation and (c) photophosphorylation of the aerobic, “pseudo- cyclic” type in which oxygen production occurs but is masked by an equal oxygen consumption. No chloride requirement was found for the anaerobic, cyclic photophosphorylation in which oxygen is not produced. These results support the view that chloride is an essential cofactor for oxygen evolution in photosynthesis.
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Online monitoring of dissolved oxygen tension in microtiter plates based on infrared fluorescent oxygen-sensitive nanoparticles

Online monitoring of dissolved oxygen tension in microtiter plates based on infrared fluorescent oxygen-sensitive nanoparticles

− 1 was estimated for the MTP cultivation. The calculated OTR in MTP and measured OTR in the shake flask did not coincide as well as in the previous examples, but were still in good agreement. Based on the DOT and OTR results, seven characteristic phases could be distin- guished in this fermentation on autoinduction media containing three different carbon sources (Fig.  6 a). The phases I—IV have already been published by Rah- men  et  al. [ 28 ]. In this mentioned study no cultivation under oxygen-limited conditions were investigated. After 4  h the first carbon source glucose was depleted indicated by a drop of the OTR and a change of the slope in the DOT (I). Subsequently, growth on glyc- erol followed for roughly 1.5  h (II). From 5.5  h simul- taneous consumption of glycerol (as energy source) and product formation (mCherry) on lactose occurred with a constant OTR of about 6.5  mmol  L − 1   h − 1 (III). Due to depletion of lactose this phase stopped after 12 h. Within the next 7 h the residual glycerol was con- sumed. This period could be divided into two phases: non-oxygen limited growth (IV: 12–17.5 h) and oxygen limited growth (V: 17.5–19 h) indicated by a plateau of the OTR curve (33.3 mmol L − 1  h − 1 ) and a DOT close to zero. Losen et al. [ 29 ] investigated the effects of oxygen limitations during E. coli cultivations. As a consequence of the oxygen limitation an enhanced production of acetate was reported. Growth on acetate was observed after depletion of the primary substrate. Thus, the OTR level of about 9.4  mmol  L − 1   h − 1 in Fig.  6 a after 19.5  h could be attributed to the consumption of acetate (VI). In the last phase (VII: 22–23 h) all carbon sources were depleted and the cultivation terminated. The differ- ent phases are also visible in the scattered light inten- sities (Fig.  6 b). Analog to Kunze et  al. [ 18 ], during the expression of mCherry a linear increase was detected (III) that turned into an exponential one when residual glycerol was consumed (IV + V). In Fig.  6 c the fluores- cence intensities of mCherry are depicted. In contrast to Kunze et al. [ 18 ], no significant influence of the dis- persed oxygen-sensitive nanoparticles on the fluores- cence measurement of mCherry was observed. Within phase I and II the fluorescence intensities remained close to zero. In both experiments, after 6  h the inten- sities started to increase due to mCherry expression, but diverged over the time. Most likely, the deviation of the presented cultivations can be attributed to slightly different starting conditions due to the separate media preparation.
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Optical oxygen sensing with artificial intelligence

Optical oxygen sensing with artificial intelligence

This work explored a new approach to optical luminescence sensing, proving that, to build an accurate oxygen sensor, it is not necessary to implement complex non-linear pseudo-physical models to describe the dependence of the measured quantity, here the phase shift, on the oxygen concentration. The sensor-specific deviations from a simple SV model may be caused, for example, by the method for the immobilization of the indicators in the substrate, or by luminescence from components typically included in a sensor, such as absorption filters or glues. Therefore, to reach a high accuracy, the classical approach requires empirically modeling the dependence of the parameters, f , K SV1 , and K SV2 , of the inverted SV multi-site model from all the relevant influencing quantities, for example the temperature or the modulation frequency. The resulting algorithms frequently are computationally intensive and per-definition only an approximation. Furthermore, for a commercial solution, it is desirable for the chosen parameterization to be valid for all sensors, with only a few parameters that need to be determined during a device-specific calibration. This imposes higher requirements, and therefore costs, on the device components, and may require further compromising on the accuracy. The proposed artificial intelligence approach has the potential to overcome these limitations.
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Evolution of Degenerate Oxygen-Neon Cores

Evolution of Degenerate Oxygen-Neon Cores

In Section 6.1, it was also pointed out that if the growth timescale of such oscillations in a semiconvec- tive regime is short, the composition gradient will quickly be erased and the region becomes convective. On the other hand, if these oscillations grow very slowly, nearly no mixing will take place. These cir- cumstances would have the same outcomes as assuming either the strict Schwarzschild or strict Ledoux criteria for convection, respectively. In the initial work on the final evolution of degenerate ONe cores (evolving toward ECSN) by Miyaji et al. (1980), ignoring the stabilizing mean molecular weight gra- dient, convection is developing in the core prior to the ignition of the oxygen deflagration, triggered by energy production due to ECs on 24 Mg and 20 Ne. Mochkovitch (1984), and subsequently Miyaji & Nomoto (1987), showed that if one considers the stabilizing effect of the stratification in mean molecular weight produced by the ECs alongside the steep temperature gradient (i.e. Ledoux criterion), the core will be stable to convection. The impact of the choice of convection criterion on the ignition density of the oxygen deflagration has since been described in several works. As already mentioned, Figure 6.4 shows the ignition densities found in various simulations from the literature. With the exception of Takahashi et al. (2013), all studies adopting the Ledoux criterion for convection find ignition densities below 10 10 g cm −3 . The key difference is that Takahashi et al. (2013) also included an approximation for semiconvective mixing processes. If, as for example in Miyaji et al. (1980), the Schwarzschild criterion for convection is assumed, this results in a convective core that delays the ignition of oxygen to a density around ≈ 2 × 10 10 g cm −3 . As pointed out by Jones et al. (2016), performing 3D hydrodynamical sim- ulations of the oxygen deflagration, ignition densities around 2 × 10 10 g cm −3 result in a core collapse, while densities around 10 10 g cm −3 result in a thermonuclear explosion.
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Weak Interactions in Degenerate Oxygen-Neon Cores

Weak Interactions in Degenerate Oxygen-Neon Cores

Following carbon burning an intermediate-mass star enters the super-AGB phase of its evolution. We refer the reader to [DGPSL17] for a thorough review on this subject. The typical structure of a star in this phase is outlined in Figure 4.3. The degenerate ONe core in the centre is surrounded by a carbon-oxygen layer which grows through thermal pulses. Such a pulse consists of unstable helium burning which rapidly (within ∼ 0.5 − 5 yrs) consumes the available fuel. The pulse will also disrupt the hydrogen burning shell further out. At a later point the hydrogen burning will resume and produce more helium that can fuel a new thermal pulse. The total number of pulses can vary from ∼ 30 to more than 2800, with the period between pulses being ∼ 30 − 1000 yrs. The thermal pulses have two main effects: Firstly, they add mass to the core and cause it to contract. Secondly, they drive powerful stellar winds which result in a significant mass loss. This loss can be so large that the entire hydrogen envelope is expelled and we are left with an ONe white dwarf.
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Oxygen diffusion in single crystal barium titanate

Oxygen diffusion in single crystal barium titanate

Oxygen diffusion in cubic, nominally undoped, (100) oriented BaTiO 3 single crystals has been studied by means of 18 O 2 / 16 O 2 isotope exchange annealing and subsequent determination of the isotope profiles in the solid by time-of-flight secondary ion mass spectrometry (ToF-SIMS). Experiments were carried out as a function of temperature 973 o T/K o 1173, at an oxygen activity of aO 2 = 0.200, and as a function of oxygen activity 0.009 o aO 2 o 0.900 at T = 1073 K. The oxygen isotope profiles comprise two parts: slow diffusion through a space-charge zone at the surface depleted of oxygen vacancies followed by faster diffusion in a homogeneous bulk phase. The entire isotope profile can be described by a single solution to the diffusion equation involving only three fitting parameters: the surface exchange coefficient k s *, the space-charge potential F 0 and the bulk diffusion coefficient D*(N). Analysis of the temperature and oxygen activity dependencies of D*(N) and F 0 yields a consistent picture of both the bulk and the interfacial defect chemistry of BaTiO 3 . Values of the oxygen vacancy diffusion coefficient D V extracted from measured D*(N) data are compared with literature data; consequently a global expression for the vacancy diffusivity in BaTiO 3 for the temperature range 466 o T/K o 1273 is obtained, with an activation enthalpy of vacancy migration, DH mig,V = (0.70  0.04) eV.
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Surface oxygen exchange between yttria-stabilised zirconia and a low-temperature oxygen rf-plasma

Surface oxygen exchange between yttria-stabilised zirconia and a low-temperature oxygen rf-plasma

[18] , which corresponds to a wavelength of 238 nm. The average kinetic energy of the electrons in the rf-plasma equals 10 eV, and thus, emission of UV photons with an energy of 5.2 eV is at least theoretically possible. Nev- ertheless we can safely assume that electron-hole forma- tion by UV irradiation plays a negligible role in the observed rate increase since the emission spectrum of our oxygen plasma shows no UV lines with such high energy. It has to be noted that even in the case of high energy UV emission the intensity of the emission would be much too low for a significant influence on the kinetics. As can be seen from Fig. 9 , a rf-power of 25 W is already sufficient to see a serious rate increase. Merkle et al. had to use a 200 W-discharge lamp in order to obtain an effect by UV irradiation.
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Privatized Keynesianism or conspicuous consumption? Status anxiety and the financialization of consumption in Chile

Privatized Keynesianism or conspicuous consumption? Status anxiety and the financialization of consumption in Chile

Keywords: trickle-down consumption effect, privatized Keynesianism, status anxiety, spu- rious mobility, relative deprivation Zusammenfassung Weshalb nehmen Verbraucher Kredite auf? Am Beispiel von Chile hinterfrage ich in diesem Beitrag die Erklärungskraft, die sowohl die Trickle-down-Theorie als auch die Theorie des privatisierten Keynesianismus bei diesem Thema entfalten. Beide Narrative erklären nicht, warum Verbraucher vor dem Hintergrund von Lohnerhöhungen Kredite nutzen, um ganz normalen Konsum zu finanzieren, der weder einen bestimmten Lebensstil absichern noch Dritten gegenüber einen bestimmten Status signalisieren soll, sondern vielmehr dazu dient, den Lebensstandard auf eher dezente Weise zu erhöhen. Ausgehend von der Vorstellung, dass private Verschuldung die Lücke zwischen Einkommen und einem sozial konstruierten Lebensstandard schließen soll, schlage ich vor, die Finanzialisierung im Fall Chiles – und wohl auch weiterer Entwicklungsländer – durch zwei nuanciertere Mechanismen zu erklä- ren: erstens durch vorgetäuschte Aufwärtsmobilität und zweitens durch relative Depriva- tion. In beiden Fällen leben Familien über ihre Verhältnisse, um ihre Klassenidentitäten auszufüllen und die Konsumstandards zu befolgen, zu denen sie sich berechtigt fühlen. Durch Kreditaufnahme möchten Verbraucher nicht die Wohlhabenden imitieren, sondern vielmehr ihre Zugehörigkeit zu einer „imaginären Mittelschicht“ zeigen.
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Fruit and vegetable consumption today

Fruit and vegetable consumption today

The 2009 »German Health Update« study (GEDA 2011) provides topical figures on the consumption of fruit and vegetables. Unlike in the EsKiMo study, the participants were asked how frequently they consumed the portions of fruits, vegetables and juice; they were not questioned about detailed amounts in grams: 12 % of 18- to 90-year-old women and 6 % of men in the same age group consumed the recommended five portions of fruit and vegetables a day. All the same, 43 % of the women and 26 % of the men ate at least three portions of plant-based foods daily. Although the proportion of people who reached the recom- mended five portions a day showed no clear age trend, the percentage of men who consumed at least three portions of fruit and vegetables a day rose significantly from the age of 50. The age profile among women was less con- sistent, but here, too, more older than younger women consumed at least three portions of fruit and vegetables a day (Figure 2).
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Consumption smoothing and vulnerability in Russia

Consumption smoothing and vulnerability in Russia

The way different individuals experience and react in periods such as this is an important policy question so we provide the first comparison for Russia of the effects of and responses to income fluctuations across the conditional distribution of consumption changes. In this, we apply Quantile Regression Methods (QRM) as proposed by Koenker and Bassett (1982). Further, as suggested by a growing literature (see Hoddinott (2006) and references therein), we take as our unit of analysis the individual, rather than the household, enabling us to account for both household and individual characteristics while still controlling for the fact that individuals typically live and share resources within a household structure. We are also more explicit than previous studies in treating observed changes in consumption as a function of the net effect of both the idiosyncratic shocks experienced by individuals as well as the risk management strategies they employ to cope with such shocks. This contrasts with Skoufias (2003) who concentrates on the likelihood of using various coping strategies rather than the explicit contribution they make to consumption smoothing. Unlike previous studies our measure of consumption excludes any imputed cash value attributed to home production thus allowing us to compare our results pertaining to home production with those of Clarke (2002). That is, we are concerned with the ability of Russian households to smooth fluctuations in their cash spending.
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Consumption selection on incomplete markets

Consumption selection on incomplete markets

prices, but instead of choosing the bond as num´ eraire right from the start we begin with an arbitrary non-decreasing process modeling bond price dynam- ics. By means of a short detour we repeat the properties needed to formulate the process polar for sets of non-negative semimartingales and the Filtered Bipolar Theorem (ˇ Zitkovi´ c, 2002). We explain wealth dynamics under the usual No-Arbitrage assumption and derive a budget constraint employing process polarity. Although our results would hold as well, we abstain from general bond price dynamics for the analysis in Sections 3 - 6 and choose bond as num´ eraire. Most assertions stay unchanged, but since bond price dynamics influences wealth dynamics, they also affect the consumption choice. More- over when bond prices raise, discounting of rate of consumption processes is necessary. In the Section 2 we give a taste how results must be carried over when the bond price is not constant.
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Consumption, money, and excess returns

Consumption, money, and excess returns

Since we will deal with excess returns R i,e of different test assets i in the empirical application below, the standard pricing equation (Cochrane, 2004) is.. E s t+1 R i,e t+1  = 0 ([r]

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