Shape-Based Tracking Allows Functional Discrimination of Two Immune Cell Subsets Expressing the Same Fluorescent Tag in Mouse Lung Explant

Dendritic Cells (DC) represent a key lung immune cell population, which play a critical role in the antigen presenting process and initiation of the adaptive immune response. The study of DCs has largely benefited from the joint development of fluorescence microscopy and knock-in technology, leading to several mouse strains with constitutively labeled DC subsets. However, in the lung most transgenic mice do express fluorescent protein not only in DCs, but also in closely related cell lineages such as monocytes and macrophages. As an example, in the lungs of CX3CR1+/gfp mice the green fluorescent protein is expressed mostly by both CD11b conventional DCs and resident monocytes. Despite this non-specific staining, we show that a shape criterion can discriminate these two particular subsets. Implemented in a cell tracking code, this quantified criterion allows us to analyze the specific behavior of DCs under inflammatory conditions mediated by lipopolysaccharide on lung explants. Compared to monocytes, we show that DCs move slower and are more confined, while both populations do not have any chemotactism-associated movement. We could generalize from these results that DCs can be automatically discriminated from other round-shaped cells expressing the same fluorescent protein in various lung inflammation models

Measurement of the B+ and B-0 lifetimes and search for CP(T) violation using reconstructed secondary vertices

The lifetimes of the B+ and B-0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z(0) decays recorded at LEP. Z(0) --> b (b) over bar decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged data sample. The results aretau(B+) = 1.643 +/- 0.037 +/- 0.025 pstau(Bo) = 1.523 +/- 0.057 +/- 0.053 pstau(B+)/tau(Bo) = 1.079 +/- 0.064 +/- 0.041,where in each case the first error is statistical and the second systematic.A larger data sample of 3.1 million hadronic Z(o) decays has been used to search for CP and CPT violating effects by comparison of inclusive b and (b) over bar hadron decays, No evidence fur such effects is seen. The CP violation parameter Re(epsilon(B)) is measured to be Re(epsilon(B)) = 0.001 +/- 0.014 +/- 0.003and the fractional difference between b and (b) over bar hadron lifetimes is measured to(Delta tau/tau)(b) = tau(b hadron) - tau((b) over bar hadron)/tau(average) = -0.001 +/- 0.012 +/- 0.008

Experimental properties of gluon and quark jets from a point source

Gluon jets are identified in hadronic Z0 decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to gluon jets produced from a color singlet point source and thus correspond to the definition employed for most theoretical calculations. In a separate stage of the analysis, we select quark jets in a manner to correspond to calculations, as the particles in hemispheres of flavor tagged light quark (uds) events. We present the distributions of rapidity, scaled energy, the logarithm of the momentum, and transverse momentum with respect to the jet axes, for charged particles in these gluon and quark jets. We also examine the charged particle multiplicity distributions of the jets in restricted intervals of rapidity. For soft particles at large transverse momentum, we observe the charged particle multiplicity ratio of gluon to quark jets to be 2.29 +- 0.09 +- 0.15 in agreement with the prediction that this ratio should approximately equal the ratio of QCD color factors, CA/CF = 2.25. The intervals used to define soft particles and large transverse momentum for this result, p<4 GeV/c and 0.8<p_t<3.0 GeV/c, are motivated by the predictions of the Herwig Monte Carlo multihadronic event generator. Additionally, our gluon jet data allow a sensitive test of the phenomenon of non-leading QCD terms known as color reconnection. We test the model of color reconnection implemented in the Ariadne Monte Carlo multihadronic event generator and find it to be disfavored by our data.Gluon jets are identified in hadronic Z0 decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to gluon jets produced from a color singlet point source and thus correspond to the definition employed for most theoretical calculations. In a separate stage of the analysis, we select quark jets in a manner to correspond to calculations, as the particles in hemispheres of flavor tagged light quark (uds) events. We present the distributions of rapidity, scaled energy, the logarithm of the momentum, and transverse momentum with respect to the jet axes, for charged particles in these gluon and quark jets. We also examine the charged particle multiplicity distributions of the jets in restricted intervals of rapidity. For soft particles at large transverse momentum, we observe the charged particle multiplicity ratio of gluon to quark jets to be 2.29 +- 0.09 +- 0.15 in agreement with the prediction that this ratio should approximately equal the ratio of QCD color factors, CA/CF = 2.25. The intervals used to define soft particles and large transverse momentum for this result, p<4 GeV/c and 0.8<p_t<3.0 GeV/c, are motivated by the predictions of the Herwig Monte Carlo multihadronic event generator. Additionally, our gluon jet data allow a sensitive test of the phenomenon of non-leading QCD terms known as color reconnection. We test the model of color reconnection implemented in the Ariadne Monte Carlo multihadronic event generator and find it to be disfavored by our data.Gluon jets are identified in hadronic Z0 decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to gluon jets produced from a color singlet point source and thus correspond to the definition employed for most theoretical calculations. In a separate stage of the analysis, we select quark jets in a manner to correspond to calculations, as the particles in hemispheres of flavor tagged light quark (uds) events. We present the distributions of rapidity, scaled energy, the logarithm of the momentum, and transverse momentum with respect to the jet axes, for charged particles in these gluon and quark jets. We also examine the charged particle multiplicity distributions of the jets in restricted intervals of rapidity. For soft particles at large transverse momentum, we observe the charged particle multiplicity ratio of gluon to quark jets to be 2.29 +- 0.09 +- 0.15 in agreement with the prediction that this ratio should approximately equal the ratio of QCD color factors, CA/CF = 2.25. The intervals used to define soft particles and large transverse momentum for this result, p<4 GeV/c and 0.8<p_t<3.0 GeV/c, are motivated by the predictions of the Herwig Monte Carlo multihadronic event generator. Additionally, our gluon jet data allow a sensitive test of the phenomenon of non-leading QCD terms known as color reconnection. We test the model of color reconnection implemented in the Ariadne Monte Carlo multihadronic event generator and find it to be disfavored by our data.Gluon jets are identified in hadronic Z0 decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to gluon jets produced from a color singlet point source and thus correspond to the definition employed for most theoretical calculations. In a separate stage of the analysis, we select quark jets in a manner to correspond to calculations, as the particles in hemispheres of flavor tagged light quark (uds) events. We present the distributions of rapidity, scaled energy, the logarithm of the momentum, and transverse momentum with respect to the jet axes, for charged particles in these gluon and quark jets. We also examine the charged particle multiplicity distributions of the jets in restricted intervals of rapidity. For soft particles at large transverse momentum, we observe the charged particle multiplicity ratio of gluon to quark jets to be 2.29 +- 0.09 +- 0.15 in agreement with the prediction that this ratio should approximately equal the ratio of QCD color factors, CA/CF = 2.25. The intervals used to define soft particles and large transverse momentum for this result, p<4 GeV/c and 0.8<p_t<3.0 GeV/c, are motivated by the predictions of the Herwig Monte Carlo multihadronic event generator. Additionally, our gluon jet data allow a sensitive test of the phenomenon of non-leading QCD terms known as color reconnection. We test the model of color reconnection implemented in the Ariadne Monte Carlo multihadronic event generator and find it to be disfavored by our data

The impact of the institutional environment on the value relevance of fair values

Most prior studies attribute valuation discounts on certain fair valued assets to measurement error or bias. We argue that institutional differences across countries (e.g., information environment or market sophistication) affect investors’ ability to process and impound fair value information in their valuation. We predict that the impact of the institutional environment on value relevance is particularly pronounced for reported fair values of assets designated at fair value through profit or loss (hereafter, “FVO assets”), for which investor experience is lowest and complexity is highest. Using a global sample of IFRS banks, we find that FVO assets are generally less value relevant than held-for-trading assets (HFT) and available-for-sale assets (AFS). By partitioning countries into market- and bank-based economies to proxy for institutional differences, we find that the valuation discount on FVO assets is more pronounced in bank-based economies. Additional tests suggest that this valuation discount is attenuated by a richer firm-level information environment and the presence of institutional investors with fair value experience

Private equity net asset values and future cash flows

This study analyzes whether fair value estimates of fund net asset values (NAVs) produced by private equity managers are accurate and unbiased predictors of future discounted cash flows (DCF). We exploit the fact that private equity funds have finite lives to compare reported NAVs to DCFs based on realized cash flows for 384 venture capital (VC) funds and 195 buyout funds spanning 1988-2016. Findings reveal that Buyout funds' NAVs display little systematic bias, but VC funds' NAVs are relatively aggressively biased compared to Buyout funds, especially since 2000. Accuracy is worse in the first half of the sample period even though NAV estimates generally are more conservative. Overall, the results reveal significant differences in the association between NAVs and DCFs for Buyout versus VC funds, which is particularly important for private equity fund investors in their consideration of the relevance and reliability of NAV estimates provided by fund managers

Private equity net asset values and future cash flows

This study analyzes whether fair value estimates of fund net asset values (NAVs) produced by private equity managers are accurate and unbiased predictors of future discounted cash flows (DCF). We exploit the fact that private equity funds have finite lives to compare reported NAVs to DCFs based on realized cash flows for 384 venture capital (VC) funds and 195 buyout funds spanning 1988-2016. Findings reveal that Buyout funds' NAVs display little systematic bias, but VC funds' NAVs are relatively aggressively biased compared to Buyout funds, especially since 2000. Accuracy is worse in the first half of the sample period even though NAV estimates generally are more conservative. Overall, the results reveal significant differences in the association between NAVs and DCFs for Buyout versus VC funds, which is particularly important for private equity fund investors in their consideration of the relevance and reliability of NAV estimates provided by fund managers

Discussion of Financial reporting for employee stock options:liabilities or equity

Barth, Hodder, and Stubben examine how the risk and expected return of existing shares varies as a function of the amount of outstanding employee stock options (ESOs), finding that the association is a negative one, consistent with ESOs being equity-like in character. They suggest that their approach could be used to address the question of how best to characterize other complex financial claims. The study is well executed and provides a thought-provoking contribution to the debate. However, it is far from obvious that the ‘‘debt or equity’’ question can be solved in this manner. Their approach effectively defines a liability as a financial claim that has characteristics akin to fixed-rate debt. I provide examples of the limitations of this perspective, starting by comparing ESOs that are settled with shares with those settled in cash. Whether a claim is treated as a liability or equity is of little con- sequence if it is simply a matter of balance sheet presentation. The real question is the implications for income measurement. I suggest progress might best be made if we start with Penman’s proposal that assets and liabilities be separated into oper- ating and financial items, an approach which would include many claims that have equity-like characteristics, such as unvested ESOs, within the operating liability category. Once a claim ceases to be an operating item—e.g. when an ESO vests—the approach suggested in the paper can then be used to determine how it should be classified

What drives the comparability effect of mandatory IFRS adoption?

We investigate the effects of mandatory IFRS adoption on the comparability of financial accounting information. Using two comparability proxies based on De Franco et al. [2011] and a comparability proxy based on the degree of information transfer, our results suggest that the overall comparability effect of mandatory IFRS adoption is marginal. We hypothesize that firm-level heterogeneity in IFRS compliance explains the limited comparability effect. To test this conjecture, we first hand-collect data on IFRS compliance for a sample of German and Italian firms and find that firm-, region-, and country-level incentives systematically shape IFRS compliance. We then use the identified compliance determinants to explain the variance in the comparability effect of mandatory IFRS adoption and find it to vary systematically with firm-level compliance determinants, suggesting that only firms with high compliance incentives experience substantial increases in comparability. Moreover, we document that firms from countries with tighter reporting enforcement experience larger IFRS comparability effects, and that public firms adopting IFRS become less comparable to local GAAP private firms from the same country