Thinly Traded Growth Stocks: A Joint Examination of Transparency in Communication and the Trading Platform

When thinly traded growth stocks (TTGS) listed on a secondary exchange experience difficulty in gaining investors' attention, one possible solution is to increase the intensity of disclosure. However, if the stock is traded on a quote-driven system, market makers can collude to maintain wide bid-ask spreads that discourage firms from disclosing. As a result, TTGS traded on a quote-driven system can face a liquidity trap that can prevent them from harvesting the benefits of increased disclosure activities. In this paper, we argue that the well-documented negative relation between disclosure and the bid-ask spread is likely to be moderated by the type of protocol chosen by exchanges to handle the trading of TTGS. To test our theory we use a unique setting created by the introduction of a hybrid order-driven protocol for TTGS in the UK. Following an increase in the disclosure activity by a TTGS, we find that the magnitudes of the predicted reductions in the bid-ask spreads are dependent on whether the TTGS switch their trading protocols. © 2013 © 2013 European Accounting Association

When geography matters: International diversification and firm performance of spanish multinationals

Indexación: Scopus.This paper studies how the nature and shape of the relationship between inter-national diversification (ID) and performance (P) may vary according to a firm’s geographical focus of internationalization. Using a sample of Spanish multinational firms for the 2004—2012 period we find an M-shaped relationship. However, significant differences are found when the different geographical foci of internationalization are considered. Strong support is found when firms adopt a regional focus (an inverted S-curve when the ID measure refers to the number of foreign countries and an M-curve when it refers to the size of the network of foreign sub-sidiaries), a biregional focus (an S-curve) and a semiglobal focus (an inverted S-curve but also an M-curve with foreign subsidiaries). These findings and their pattern suggest the critical impor-tance of the country of origin and the geographical focus of internationalization in explaining the relationship between ID—P.https://journals.sagepub.com/doi/10.1177/234094442089898

Pancreatic window and open necrosectomy; a surgical alternative for walled-off pancreatic necrosis in a second level hospital in Mexico

Walled-off pancreatic necrosis is defined as a necrotic collection with a defined wall, which generally occurs in 15% of patients in the fourth week after acute pancreatitis. Actually, open surgery is reserved for selected cases, with minimally invasive treatments such as image-assisted percutaneous drainage or endoscopic ultrasound being the procedures of choice. However, in developing countries the open approach continues to be an effective therapeutic alternative. We present the case of a 47-year-old male patient with no significant history who developed severe acute pancreatitis secondary to hypertriglyceridemia and who later developed walled-off pancreatic necrosis as a late complication. As a treatment, a debridement of the necrotic tissue with marsupialization was performed using the bradley III technique, secondary to the procedure, a pancreatic fistula was developed. After 8 weeks of hospitalization, in which he had a favourable response to surgical treatment, with spontaneous closure of the fistula without complications. Surgical management of late complications of acute pancreatitis remains controversial. Although minimally invasive procedures are the first option nowadays, in developing countries, open necrosectomy remains a good option for the treatment of these types of complications

Boolean network model predicts cell cycle sequence of fission yeast

A Boolean network model of the cell-cycle regulatory network of fission yeast (Schizosaccharomyces Pombe) is constructed solely on the basis of the known biochemical interaction topology. Simulating the model in the computer, faithfully reproduces the known sequence of regulatory activity patterns along the cell cycle of the living cell. Contrary to existing differential equation models, no parameters enter the model except the structure of the regulatory circuitry. The dynamical properties of the model indicate that the biological dynamical sequence is robustly implemented in the regulatory network, with the biological stationary state G1 corresponding to the dominant attractor in state space, and with the biological regulatory sequence being a strongly attractive trajectory. Comparing the fission yeast cell-cycle model to a similar model of the corresponding network in S. cerevisiae, a remarkable difference in circuitry, as well as dynamics is observed. While the latter operates in a strongly damped mode, driven by external excitation, the S. pombe network represents an auto-excited system with external damping.Comment: 10 pages, 3 figure

The deep inferior epigastric artery perforator flap: a review

Breast cancer is recognized worldwide as a major health problem among women due to its high incidence and high mortality and morbidity rates. Breast reconstruction is an approach of great value for those patients who underwent mastectomy, impacting their quality of life and psychological stress. The deep inferior epigastric artery perforator (DIEP) flap was described as the preferred graft for breast reconstruction with an autologous flap by surgeons because it represented a decrease in complications for the time and obtained better results. DIEP flap reconstruction requires microsurgical skills as well as continuous monitoring of the patient to identify and resolve possible associated complications.

Flower Development as an Interplay between Dynamical Physical Fields and Genetic Networks

In this paper we propose a model to describe the mechanisms by which undifferentiated cells attain gene configurations underlying cell fate determination during morphogenesis. Despite the complicated mechanisms that surely intervene in this process, it is clear that the fundamental fact is that cells obtain spatial and temporal information that bias their destiny. Our main hypothesis assumes that there is at least one macroscopic field that breaks the symmetry of space at a given time. This field provides the information required for the process of cell differentiation to occur by being dynamically coupled to a signal transduction mechanism that, in turn, acts directly upon the gene regulatory network (GRN) underlying cell-fate decisions within cells. We illustrate and test our proposal with a GRN model grounded on experimental data for cell fate specification during organ formation in early Arabidopsis thaliana flower development. We show that our model is able to recover the multigene configurations characteristic of sepal, petal, stamen and carpel primordial cells arranged in concentric rings, in a similar pattern to that observed during actual floral organ determination. Such pattern is robust to alterations of the model parameters and simulated failures predict altered spatio-temporal patterns that mimic those described for several mutants. Furthermore, simulated alterations in the physical fields predict a pattern equivalent to that found in Lacandonia schismatica, the only flowering species with central stamens surrounded by carpels

Boolean network simulations for life scientists

Modern life sciences research increasingly relies on computational solutions, from large scale data analyses to theoretical modeling. Within the theoretical models Boolean networks occupy an increasing role as they are eminently suited at mapping biological observations and hypotheses into a mathematical formalism. The conceptual underpinnings of Boolean modeling are very accessible even without a background in quantitative sciences, yet it allows life scientists to describe and explore a wide range of surprisingly complex phenomena. In this paper we provide a clear overview of the concepts used in Boolean simulations, present a software library that can perform these simulations based on simple text inputs and give three case studies. The large scale simulations in these case studies demonstrate the Boolean paradigms and their applicability as well as the advanced features and complex use cases that our software package allows. Our software is distributed via a liberal Open Source license and is freely accessible fro

The logic of the floral transition: reverse-engineering the switch controlling the identity of lateral organs

Much laboratory work has been carried out to determine the gene regulatory network (GRN) that results in plant cells becoming flowers instead of leaves. However, this also involves the spatial distribution of different cell types, and poses the question of whether alternative networks could produce the same set of observed results. This issue has been addressed here through a survey of the published intercellular distribution of expressed regulatory genes and techniques both developed and applied to Boolean network models. This has uncovered a large number of models which are compatible with the currently available data. An exhaustive exploration had some success but proved to be unfeasible due to the massive number of alternative models, so genetic programming algorithms have also been employed. This approach allows exploration on the basis of both data-fitting criteria and parsimony of the regulatory processes, ruling out biologically unrealistic mechanisms. One of the conclusions is that, despite the multiplicity of acceptable models, an overall structure dominates, with differences mostly in alternative fine-grained regulatory interactions. The overall structure confirms the known interactions, including some that were not present in the training set, showing that current data are sufficient to determine the overall structure of the GRN. The model stresses the importance of relative spatial location, through explicit references to this aspect. This approach also provides a quantitative indication of how likely some regulatory interactions might be, and can be applied to the study of other developmental transitions