Ernst Freund as Precursor of the Rational Study of Corporate Law

Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe

Pseudomonas aeruginosa clinical blood isolates display significant phenotypic variability.

Pseudomonas aeruginosa is a significant threat in healthcare settings where it deploys a wide host of virulence factors to cause disease. Many virulence-related phenotypes such as pyocyanin production, biofilm formation, and twitching motility have been implicated in causing disease in a number of hosts. In this study, we investigate these three virulence factors in a collection of 22 clinical strains isolated from blood stream infections. Despite the fact that all 22 strains caused disease and came from the same body site of different patients, they show significant variability in assays for each of the three specific phenotypes examined. There was no significant correlation between the strength of the three phenotypes across our collection, suggesting that they can be independently modulated. Furthermore, strains deficient in each of the virulence-associated phenotypes examined could be identified. To understand the genetic basis of this variability we sequenced the genomes of the 22 strains. We found that the majority of genes responsible for pyocyanin production, biofilm formation, and twitching motility were highly conserved among the strains despite their phenotypic variability, suggesting that the phenotypic variability is likely due to regulatory changes. Our findings thus demonstrate that no one lab-assayed phenotype of pyocyanin production, biofilm production, and twitching motility is necessary for a P. aeruginosa strain to cause blood stream infection and that additional factors may be needed to fully predict what strains will lead to specific human diseases

Simple Experimental Methods for Determining the Apparent Focal Shift in a Microscope System

<div><p>Three-dimensional optical microscopy is often complicated by a refractive index mismatch between the sample and objective lens. This mismatch causes focal shift, a difference between sample motion and focal-plane motion, that hinders the accuracy of 3D reconstructions. We present two methods for measuring focal shift using fluorescent beads of different sizes and ring-stained fluorescent beads. These simple methods are applicable to most situations, including total internal reflection objectives and samples very close to the interface. For distances 0–1.5 <i>μ</i>m into an aqueous environment, our 1.49-NA objective has a relative focal shift of 0.57 ± 0.02, significantly smaller than the simple <i>n</i>₂/<i>n</i>₁ approximation of 0.88. We also expand on a previous sub-critical angle theory by means of a simple polynomial extrapolation. We test the validity of this extrapolation by measuring the apparent focal shift in samples where the refractive index is between 1.33 and 1.45 and with objectives with numerical apertures between 1.25 and 1.49.</p></div

Relative focal shift as measured as the distance between beads of different sizes.

<p>(A) Example images with a sample of three types of beads (100 nm TetraSpeck, 510 nm Dragon Green, 1040 nm Dragon Green) are shown at different sample positions. (B) Brenner gradients for three example beads highlighted in panel A. (C) Box and whisker plots of the full-width at half-maximum Brenner gradient (brown) and peak intensity (green). (D) Histograms of relative distances between beads and the plane of the smallest beads. (E) Sample motion needed to refocus from one size bead to another is proportional to the difference in their sizes. <i>α</i> is the slope of this line. Colors as in panel D. <i>x</i> error bars are standard deviations of observed positions. <i>y</i> error bars are 5% relative deviation in bead diameter. Solid line is the fit <i>y</i> = <i>αx</i> and the dashed lines are the 95% C.I. for <i>α</i>. (F) Standard deviation of bead positions, measured by Brenner gradient (brown) and peak intensity (green). 99% C.I. for <i>σ</i> is calculated from a bootstrap analysis and displayed as the error bars.</p

Polynomial extrapolation of relative focal shift as a function of NA and <i>n</i>₂.

<p>(A) <i>α</i>_<i>poly</i> as a function of NA and <i>n</i>₂. The colormap (inset) gives the value of <i>α</i>. The TIR region is marked by a dashed gold line. Colored arrowheads indicate where the 1D slices through this surface are taken for panels C and D. (B) The order of the polynomial extrapolation is chosen as the lowest order whose maximal error (grape) is less than the maximal difference between <i>α</i>₆₄₆ and <i>α</i>₄₈₉ (cocoa). (C-D) <i>α</i> evaluated by the theory in [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134616#pone.0134616.ref002" target="_blank">2</a>] at various values of NA and <i>n</i>₂ (symbols) along with the global fit to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134616#pone.0134616.e003" target="_blank">Eq 3</a> (lines). Symbols that corresponding to TIR systems are shown as faded circles. (C) <i>α</i> as a function of refractive index for three different values of numerical aperture (1.00 in turquoise, 1.38 in olive, 1.48 in orchid). Also included is the <i>n</i>₂/<i>n</i>₁ approximation (gray—⋅⋅). (D) <i>α</i> as a function of numerical aperture for three different values of <i>n</i>₂ (1.33 in pistachio, 1.38 in goldenrod, 1.43 in periwinkle). (E) Experimentally observed <i>α</i> for imaging system of varying refractive index. Refractive index of the medium was increased by including glycerol (cornflower) or sucrose (dark red). Two copies of the same model of objective were measured, results from one are filled symbols and the other are open. Evaluating the <i>α</i>_<i>poly</i> with an NA of 1.49 is shown in charcoal. <i>α</i> error bars are 90% CI. <i>n</i>₂ error bars reflect changes in additive concentration by ± 1.5%. (F) Experimentally observed <i>α</i>_{<i>multiBead</i>} as a function of NA for imaging systems with various objectives using the multiple bead sizes method.</p

Summary of a variety of methods used to measure relative focal shift.

<p>Values are reported for our highest NA objectives, NA 1.49, imaging into an aqueous environment, <i>n</i>₂ = 1.33.</p

Fluorescent images showing the disparity between slices in a single focal plane and along the focal dimension.

<p>Scale bars are 1 μm. (A-E) <i>E. coli</i> cell stained with a membrane dye (FM 4–64). (F-J) 1 <i>μ</i>m sphere with a fluorescent ring stain. (A,F) <i>xy</i> slice (B,G) <i>xz</i> slice showing the apparent elongation of the object along the focal axis. (C,H) Active contour fit to the ridge of maximal intensity in red. (D,I) Stretched circle fit in blue <i>r</i>² = (<i>αz</i>)² + <i>x</i>². (E,J) <i>xz</i> slice shown after scaling <i>z</i> by <i>α</i>.</p

Properties of objectives used to test the versatility of the multiple bead method.

<p>Properties of objectives used to test the versatility of the multiple bead method.</p