Experimental Observations of Group Synchrony in a System of Chaotic Optoelectronic Oscillators

We experimentally demonstrate group synchrony in a network of four nonlinear optoelectronic oscillators with time-delayed coupling. We divide the nodes into two groups of two each, by giving each group different parameters and by enabling only inter-group coupling. When coupled in this fashion, the two groups display different dynamics, with no isochronal synchrony between them, but the nodes in a single group are isochronally synchronized, even though there is no intra-group coupling. We compare experimental behavior with theoretical and numerical results

SOAR (Support Office for Aerogeophysical Research) Annual Report 1995/1996

The Support Office for Aerogeophysical Research (SOAR) was a facility of the National Science Foundation's Office of Polar Programs whose mission is to make airborne geophysical observations available to the broad research community of geology, glaciology and other sciences. The central office of the SOAR facility is located in Austin, Texas within the University of Texas Institute for Geophysics. Other institutions with significant responsibilities are the Lamont­ Doherty Earth Observatory of Columbia University and the Geophysics Branch of the U.S . Geological Survey. This report summarizes the goals and accomplishments of the SOAR facility during 1995/1996 and plans for the next year.National Science Foundation's Office of Polar ProgramsInstitute for Geophysic

Loss of dependence on IGF-1 for proliferation of human thyroid adenoma cells.

The proliferative responses to IGF-1 (Somatomedin C) and TSH, as assessed by 3H-thymidine (3H-TdR) incorporation and autoradiographic labelling index (LI), of suspension and monolayer cultures of human thyroid follicular epithelium derived from both normal and adenoma tissue have been compared. In cultures of normal follicles, whilst neither TSH nor IGF-1 alone produced any effect, a combination of TSH (0.1 mU ml-1) together with IGF-1 (10 ng ml-1) induced a highly significant proliferative response as shown by a peak of 3HTdR incorporation and LI, 4-5 days after growth factor addition. The TSH concentration-effect curve was bell-shaped, a higher concentration of TSH (10 mU ml-1) resulting in a reduced response. In cultures derived from adenoma tissue, however, TSH alone at 0.1 mU ml-1 was sufficient to permit a highly significant proliferative response (equivalent to, or greater than the normal) in 4 out of 5 adenomas examined; again a higher concentration of TSH (10 mU ml-1) resulted in a diminished response. Addition of IGF-1 (10 ng ml-1) produced no significant change in the response to TSH (0.1 mU ml-1) in 3 of these 4 adenomas, and significantly inhibited the response in the fourth adenoma. It is concluded that escape from the requirement for an exogenous source of IGF-1 may be a key step in the development of human thyroid epithelial (follicular cell) neoplasia

A Theory Of Bust-Up Corporate Takeovers

Quite often, the market value of a firm in parts exceeds its value as a single entity.  The maximum value can be attained in such instances, by splitting the firm up.  We observe several instances where a firm’s management breaks up the firm to achieve maximum value.  In other cases, firms require a change in management to initiate divestiture. Lastly, takeover by outsiders is sometimes required to split the firm up and sell it in parts to achieve full value.  This study provides an economic analysis of the payoffs to all parties involved in a corporate breakup.  Models of the costs and benefits to shareholders and management teams are developed for each of the three situations listed above to explain why the different circumstances occur in different cases

Founders Versus Descendants: Evidence Of The Taiwanese Publicly Traded Firms

This study investigates the performance of founder-controlled firms vis-à-vis firms controlled by founders’ descendants and relatives among Taiwanese publicly traded firms.  After adjusting for size, age, growth potential, financial leverage, and industry effects, we find that the Taiwanese descendant-controlled firms underperform the matching founder-controlled firms.  In searching for the potential reasons, we find that the average board size for the descendant-controlled firms is significantly larger than that of the founder-controlled firms.  In addition, the ratios of family-related supervisors and board members of the descendant-controlled firms are significantly higher than those of the matching founder-controlled firms.  While the significantly larger board size suggests a potential power struggle between the controlling family and the non-family related board members, the stronger family domination in the board of directors and supervisors for the descendant-controlled firms provides room for entrenchment and tunneling.  In light of the absence of large outside blockholders and relatively weaker legal protections, the minority shareholders of Taiwanese firms are dependent upon internal monitoring mechanisms to protect them from the expropriation of the controlling families.  However, our results indicate that family control has undermined the internal monitoring mechanism of the Taiwanese descendant-controlled firms

Group 13 HOX proteins interact with the MH2 domain of R-Smads and modulate Smad transcriptional activation functions independent of HOX DNA-binding capability

Interactions with co-factors provide a means by which HOX proteins exert specificity. To identify candidate protein interactors of HOXA13, we created and screened an E11.5–E12.5, distal limb bud yeast two-hybrid prey library. Among the interactors, we isolated the BMP-signaling effector Smad5, which interacted with the paralogous HOXD13 but not with HOXA11 or HOXA9, revealing unique interaction capabilities of the AbdB-like HOX proteins. Using deletion mutants, we determined that the MH2 domain of Smad5 is necessary for HOXA13 interaction. This is the first report demonstrating an interaction between HOX proteins and the MH2 domain of Smad proteins. HOXA13 and HOXD13 also bind to other BMP and TGF-β/Activin-regulated Smad proteins including Smad1 and Smad2, but not Smad4. Furthermore, HOXD13 could be co-immunoprecipitated with Smad1 from cells. Expression of HOXA13, HOXD13 or a HOXD13 homeodomain mutant (HOXD13(IQN>AAA)) antagonized TGF-β-stimulated transcriptional activation of the pAdtrack-3TP-Lux reporter vector in Mv1Lu cells as well as the Smad3/Smad4-activated pTRS(6)-E1b promoter in Hep3B cells. Finally, using mammalian one-hybrid assay, we show that transcriptional activation by a GAL4/Smad3-C-terminus fusion protein is specifically inhibited by HOXA13. Our results identify a new co-factor for HOX group 13 proteins and suggest that HOX proteins may modulate Smad-mediated transcriptional activity through protein–protein interactions without the requirement for HOX monomeric DNA-binding capability

Pseudo-Riemannian Structures in Pati-Salam models

We discuss the role of the pseudo-Riemannian structure of the finite spectral triple for the family of Pati-Salam models. We argue that its existence is a very restrictive condition that separates leptons from quarks, and restricts the whole family of Pati-Salam models into the class of generalized Left-Right Symmetric Models