DSpace Collection:
https://hdl.handle.net/20.500.12202/3942
2024-03-29T09:57:29ZSynergy between antifreeze proteins is driven by complementary ice-binding
https://hdl.handle.net/20.500.12202/10035
Title: Synergy between antifreeze proteins is driven by complementary ice-binding
Authors: Drori, Ran
Abstract: In some cold-adapted organisms, over a dozen isoforms of antifreeze (glyco)proteins or AF(G)Ps are present. Although these isoforms are structurally similar, their ability to inhibit ice growth varies significantly, and, in some fish, passive isoforms can be much more abundant than the active ones. Laboratory experiments demonstrated more than a decade ago that mixtures of AFP isoforms can exhibit synergistic enhancement of each other's activity. The mechanism of this synergy effect has remained obscure and is addressed here. Using cold-stages, microfluidics, and fluorescence microscopy, the activity of binary mixtures of structurally distinct AF(G)Ps from different fish and plant species was measured. While several mixtures exhibited enhancement, some mixtures exhibited antagonism. These latter mixtures included AF(G)Ps that bind to the same crystal planes, thereby exhibiting competition. Fluorescence microscopy experiments with a synergistic mixture of two isoform types labeled with different dyes showed they bound to different crystal planes. These results helped develop a kinetic description of the mechanism by which AF(G)Ps achieve synergy. The requirements of an active isoform include high adsorption rates, and prism plane binding, while passive isoforms usually bind to a pyramidal plane at slower rates. For synergy to occur, an active isoform first binds to the faster growing prism plane. This binding slows the advancement of the prism plane and creates more pyramidal surfaces to which a passive isoform bind. These results, in part, explain the biological observation of isoform distribution in fish, and the physical chemistry of the synergistic crystal growth inhibition by two inhibitors.
Description: Scholarly articleRandom sequential adsorption on euclidean, fractal and random lattices
https://hdl.handle.net/20.500.12202/10034
Title: Random sequential adsorption on euclidean, fractal and random lattices
Authors: Cwilich, Gabriel; Pasinetti, Pedro M.; Ramirez, Lucia S.; Centres, Paulo M.; Ramirez-Pastor, Antonio J.
Abstract: Irreversible adsorption of objects of diferent shapes and sizes on Euclidean, fractal and random
lattices is studied. The adsorption process is modeled by using random sequential adsorption (RSA)
algorithm. Objects are adsorbed on one-, two-, and three-dimensional Euclidean lattices, on Sierpin-
ski carpets having dimension d between 1 and 2, and on Erdos-Renyi random graphs. The number
of sites is M = Ld for Euclidean and fractal lattices, where L is a characteristic length of the sys-
tem. In the case of random graphs it does not exist such characteristic length, and the substrate
can be characterized by a xed set of M vertices (sites) and an average connectivity (or degree)
g. The paper concentrates on measuring (1) the probability WL(M)( ) that a lattice composed of
Ld(M) elements reaches a coverage , and (2) the exponent j characterizing the so-called \jamming
transition". The results obtained for Euclidean, fractal and random lattices indicate that the main
quantities derived from the jamming probability WL(M)( ) behave asymptotically as M1=2. In the
case of Euclidean and fractal lattices, where L and d can be de ned, the asymptotic behavior can
be written as M1=2 = Ld=2 = L1= j , and j = 2=d.
Description: Scholarly working paper / Open Access2019-01-01T00:00:00ZAghamolla, C., & Hashimoto, T. (2020). Information arrival, delay, and clustering in financial markets with dynamic freeriding. Journal of Financial Economics, 138(1), 27-52.
https://hdl.handle.net/20.500.12202/9869
Title: Aghamolla, C., & Hashimoto, T. (2020). Information arrival, delay, and clustering in financial markets with dynamic freeriding. Journal of Financial Economics, 138(1), 27-52.
Authors: Hashimoto, Tadashi
Abstract: Aggressive Boards and CEO Turnover∗
Cyrus Aghamolla† Tadashi Hashimoto‡
January 4, 2021
Abstract
This study investigates a communication game between a CEO and a board of
directors where the CEO’s career concerns can potentially impede value-increasing
informative communication. By adopting a policy of aggressive boards (excessive
replacement), shareholders can facilitate communication between the CEO and the
board. The results are in contrast to the multitude of models which generally find that
management-friendly boards improve communication, and help to explain empirical
results concerning CEO turnover. The results also provide the following novel pre-
dictions concerning variation in CEO turnover: (i) there is greater CEO turnover in
firms or industries where CEO performance is relatively more difficult to assess; (ii)
the board is more aggressive in their replacement of the CEO in industries or firms
where the board’s advisory role is more salient; and (iii) there is comparatively less
CEO turnover in firms or industries where the variance of CEO talent is high.
Description: Scholarly article2021-01-01T00:00:00ZInformation arrival, delay, and clustering in financial markets with dynamic freeriding
https://hdl.handle.net/20.500.12202/9868
Title: Information arrival, delay, and clustering in financial markets with dynamic freeriding
Authors: Hashimoto, Tadashi; Aghamolla, Cyrus
Abstract: We study informational freeriding in a model where agents privately acquire information and then decide when to reveal it by taking an action. Examples of such freeriding are prevalent in financial markets, e.g., the timing of initial public offerings, analysts’ forecasts, and mutual funds’ investment decisions. The main results show that, in large populations, few agents provide significant information while the vast majority of agents freeride. We highlight the role of uncertainty and market size in shaping the dynamics of price discovery. Among other results, we find that heightened uncertainty over the underlying state enhances information production, yet weakens the precision and speed of information aggregation in the market.
Description: Scholarly article2020-01-01T00:00:00Z