Corporate Law and Corporate Governance

Transaction cost economics has done much to illuminate the workingof corporate governance devices, and we have seen a revivalof interest in corporate law and corporate governance sincethe 1980s, as researchers applied the tools of the new institutionaleconomics and modern corporate finance to analyze the new transactionsemerging in the 1980s takeover wave. This article focuses onthree mechanisms of corporate governance, to illustrate theanalytical usefulness of transaction cost economics for corporatelaw. It begins with the role of the board of directors, theprincipal governance structure for shareholders in diffuselyheld firms, for which Oliver Williamson provided the key conceptualization.It then extends that analysis to a form of block ownership knownas relational investing, in which a large shareholder is moreactively involved in firm management than is ordinarily expectedof non-management shareholders. It concludes with an examinationof the choice of law governing shareholder-manager relations,referred to in the literature as state competition for corporatecharters, and how Williamson's framework can be fruitfully deployedfor understanding the success of US corporate law. Each of thethree sections sketches first the theory of the corporate governancemechanism from the perspective of transaction cost economicsand then addresses the question whether corporate governancematters by discussing the empirical evidence on whether themechanism is effective. In addition to limning Williamson'scontribution, the objective is to relate theory and data, toascertain where we are, 20 years after Williamson's fundamentalcontribution was first articulated in Markets and Hierarchies,and over a decade after the corporate law applications werefirst explicitly worked out.     

Heat Transfer to Non-Newtonian Fluid Foods under Laminar Flow Conditions in Horizontal Tubes

This paper presents a study of rates of heat transfer to non-Newtonian fluid foods: mango and papaya nectars, passing through horizontal tubes of circular cross section under laminar flow conditions. Determination of the flow and thermal properties of the fluids under study was performed to adequately explain heat transfer experiences. A laminar mixed convection equation was used for describing experimental heat transfer coefficients: Nu = 1.75 [Gz + 0.0083 (Gr_w . Pr_W)^0.75]^1/3 . δ^1/3 . (K_b/K_w)^0.14 The experimental data covered Graetz numbers between 500 and 7000, and were correlated with a mean deviation of 8.4%. The results should be helpful for interpreting heat transfer to pseudoplastic materials in the design of double tube heat exchangers.     

Evaluation of Fermentative Bacteria in a Model Low Salt Cucumber Juice Brine

Bifidobacterium bifidum, Lactobacillus casei, Lactobacillus plantarum, Lactococcus diacetylactis, Leuconostoc mesenteroides, Leuconostoc oenos, Pediococcus pentosaceus and a mixed culture of Propionibacterium shermanii and P. pentosaceus were used to ferment a model low salt (2.5% NaCl) cucumber juice brine at 22–26°C for 39 days. Percent sugar fermented ranged from 16.2 to 87.7. Substrates were citric acid, fructose, glucose and malic acid. Fermentation products quantitated were acetic acid, acetoin, ethanol, lactic acid, mannitol, and propionic acid with percent carbon recovery varying from 71.1 to 101.1. Final pH ranged 3.24 to 4.12. Each fermentation differed quantitatively in substrates and products formed suggesting use of these bacteria as cultures to ferment low salt brined cucumbers and generate a variety of unique organoleptic properties.     

OXYGEN TRANSMISSION RATE of an EDIBLE METHYLCELLULOSE-PALMITIC ACID FILM1

Edible coatings with low potassium sorbate permeability could be used to increase the microbial stability of food surfaces. However, such coatings could induce anaerobic food conditions if their oxygen permeability were low. the oxygen permeability of an edible emulsion film (average thickness, 55 μm), composed of methylcellulose and palmitic acid (weight ratio of 3:1), was evaluated at 24°C, atmospheric pressure, and at different percentages of relative humidity (RH). RH values in the 0–57% range had no significant effect on oxygen transmission rate (OTR); calculated OTR values ranged from 660 to 740 mL O₂ (STP)/m² 24h atm. At 79% RH, the OTR doubled to 1,500 mL O₂ (STP)/m² 24h atm. This effect correlated well with the moisture isotherm for the film which showed a low moisture content in the 0–57% RH range and a rapid increase at higher RH values. OTR values, particularly at high relative humidity, indicate no risk of developing anaerobic conditions on the food surface.     

Structural performance assessment of GFRP elastic gridshells by machine learning interpretability methods

The prediction of structural performance plays a significant role in damage assessment of glass fiber reinforcement polymer (GFRP) elastic gridshell structures. Machine learning (ML) approaches are implemented in this study, to predict maximum stress and displacement of GFRP elastic gridshell structures. Several ML algorithms, including linear regression (LR), ridge regression (RR), support vector regression (SVR), K-nearest neighbors (KNN), decision tree (DT), random forest (RF), adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), category boosting (CatBoost), and light gradient boosting machine (LightGBM), are implemented in this study. Output features of structural performance considered in this study are the maximum stress as f₁(x) and the maximum displacement to self-weight ratio as f₂(x). A comparative study is conducted and the Catboost model presents the highest prediction accuracy. Finally, interpretable ML approaches, including shapely additive explanations (SHAP), partial dependence plot (PDP), and accumulated local effects (ALE), are applied to explain the predictions. SHAP is employed to describe the importance of each variable to structural performance both locally and globally. The results of sensitivity analysis (SA), feature importance of the CatBoost model and SHAP approach indicate the same parameters as the most significant variables for f₁(x) and f₂(x).     

On the synthesis of all-pass digital transfer functions based on LBR two-pair extraction procedure†

In this paper a simple explicit expression is provided for the parameter a in LBR two-pairs used in the synthesis of all-pass digital transfer functions. The result can be of interest in automated procedures for digital filter design. Further, canonical realizations for this type of two-pairs are given.     

CORRELATION AMONG METALLIC IONS,PHENOLIC COMPOUNDS AND ANTIMICROBIAL ACTION IN MEDICINAL PLANTS EXTRACTS

ABSTRACT

The extracts of three different medicinal plants –Calendula officinalis L., Maytenus ilicifolia Martius ex Reissek and Cymbopogon citratus (DC) Stapf – obtained with 70% and 95% v/v ethanol had their antimicrobial activity tested against five pathogenic microorganisms. A quantitative analysis of total phenols, flavonoids and mineral species was performed on the extracts using UV‐vis spectroscopy and atomic absorption spectroscopy. Klebsiella pneumoniae showed the greatest sensibility to the extracts tested. The mineral content of the medicinal herbs varied according to the type of plant (Cu = not detected to 10.90; Zn = 0.85 to 10.04; Na = 24.94 to 153.62; Al = 90.04 to 420.39; Mg = 9.62 to 1,129.15; Ca = 7.15 to 167.27 and K = 913.85 to 9,578.94 µg/g); however, the concentration of heavy elements (Pb, Cd and Cr) was null in the extracts. The concentrations of flavonoids ranged from 13.55 to 41.54 mg/g and 92.35 to 518.28 mg/g for phenolic acids.

PRACTICAL APPLICATIONS

The use of plants with pharmacological activities has increased significantly because of their functional properties in the diet for the promotion of human health and antimicrobial effects. Moreover, medicinal herbs play an important role in public health, especially in developing countries. In Brazil, the use of plant extracts in the treatment of certain diseases is very common. This habit can be explained, at least in part, by the belief that herbs with therapeutic effects do not have toxic effects on the organism. In this paper, ethanolic extracts of three medicinal plants, widely cultivated and used by the population of Brazil and worldwide, had their levels of metals ions and total phenolic compounds determined. Antimicrobial activity of the extracts was evaluated against foodborne pathogens or food spoilage organisms or clinically isolates microorganisms.