Why the Universe is Just So

Some properties of the universe are fixed by physics derived from mathematical symmetries, others may have been selected from an ensemble of possibilities. Some successes and failures of anthropic reasoning in this context are reviewed in the light of recent developments in astrobiology, cosmology and unification physics. Specific issues raised include our spacetime location (including the reason for the present age of the universe), the timescale of biological evolution, the tuning of global cosmological parameters, the origin of the Large Numbers of astrophysics, and the parameters of the Standard Model. Out of the twenty parameters of the Standard Model,the basic behavior and structures of the world (nucleons, nuclei,atoms, molecules, planets, stars, galaxies) depend mainly on five of them: $m_e,m_u,m_d,\alpha,\alpha_G$, three of which are independent in the context of Grand Unified Theories (that is, not related by any known symmetry). These parameters also need to be finely tuned to make stable nucleons and nuclei and abundant carbon, leading to the conjecture that the two light quark masses and one coupling constant are ultimately determined even in the ``Final Theory'' by a choice from a continuous ensemble, and the prediction that the correct unification scheme will not allow calculation of $(m_d-m_u)/m_{proton}$ from first principles

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 326)

This bibliography lists 108 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during July, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

Model of macroeconomic evolution in stable regionally dependent economic fields

We develop a model for the evolution of economic entities within a geographical type of framework. On a square symmetry lattice made of three (economic) regions, firms, described by a scalar fitness, are allowed to move, adapt, merge or create spin-offs under predetermined rules, in a space and time dependent economic environment. We only consider here one timely variation of the ''external economic field condition''. For the firm fitness evolution we take into account a constraint such that the disappearance of a firm modifies the fitness of nearest neighboring ones, as in Bak-Sneppen population fitness evolution model. The concentration of firms, the averaged fitness, the regional distribution of firms, and fitness for different time moments, the number of collapsed, merged and new firms as a function of time have been recorded and are discussed. Also the asymptotic values of the number of firms present in the three regions together with their average fitness, as well as the number of respective births and collapses in the three regions are examined. It appears that a sort of $critical$ selection pressure exists. A power law dependence, signature of self-critical organization is seen in the birth and collapse asymptotic values for a high selection pressure only. A lack of self-organization is also seen at region borders.Comment: 11 figures double columns on 7 page

Impacto de la biotecnología en la inmunología

La biotecnología ha conducido al desarrollo de la inmunología en la generación de pruebas diagnósticas, fármacos y vacunas, útiles en la profilaxia, diagnóstico y tratamiento de una variedad de enfermedades infecciosas y autoinmunitarias y el cáncer. Hoy en día se reconoce que no sólo los investigadores, sino también las principales compañías farmacéuticas internacionales, han comprendido que la terapia tradicional con productos químicos y farmacéuticos está siendo reemplazada por productos derivados de la biotecnología, particularmente la aplicada a la inmunología (conocida como inmunobiotecnología), principalmente por su efectividad en aspectos de salud, pero también debido a que es ecológicamente sustentable y generadora de riqueza comercial

Central Path Dynamics and a Model of Competition, II

Growth -- the change in number or size -- and adaptation -- the change in quality or structure -- are key attributes of global processes in natural communities, society and economics (see, e.g. Hofbauer and Sigmund, 1988; Freedman, 1991; Young, 1993). In this paper we describe a model with explicit growth-adaptation feedbacks. We treat it in the form of an economic model of competition of two firms (with several departments) on the market. Their size is measured by their capital, and their quality by their productive power (production complexity). It is assumed that the production complexity of a department or firm is a simple function (that is more general than the one considered in Krazhimskii and Stoer, 1999) of its capital. The model works on both the firm level (competition among the departments) and the market level (competition among the firms). The model shows some empirically observable phenomena. Typically, one of the firms will finally cover the market. The winner is not necessarily the firm with the potentially higher maximum productivity. A long-term coexistence of firms may arise in exceptional situations occurring only when the maximum potential productivities (not the actual productivities) are equal. The analysis is also based on the concept of central paths from the interior point optimization theory (see Sonnevend, 1985; and e.g., Ye, 1997)

Quality adjustment in non-spanning markets with variety aversion

This paper examines the dynamic process of quality adjustment in cases where the economy lacks a sufficient number of markets for coordinating the level of attributes that configure the qualities of products. It shows that an adjustment process through the development and selection of commodities with different qualities may succeed in achieving efficiency or at least, meet the necessary conditions for efficiency. This is true if the user can identify with the altered product and is unaffected by variety in the commodity. It also holds true when the consumer assesses product variety in a smooth (differentiable) function, but not necessarily so if the assessment is non-smooth regarding the homogeneous state. An unidentifiable case can also be subject to inefficiency as the effort of a small quality adjusting agent becomes attenuated

Neuroprotection: VEGF, IL-6, and clusterin: the dark side of the moon

Growth factors and their respective receptors are key regulators in development and homeostasis of the nervous system, and changes in the function, expression, or downstream signaling of growth factors are involved in many neuropathological disorders. Recently, research has yielded a rich harvest of information about molecules and gene, and currently the assumption "a gene-a protein", where each gene encodes the structure of a single protein, is becoming a paradox. In the past years, the discovery of synergic or antagonistic proteins deriving from the same gene is a novelty upsetting. In some way, the conventional function of proteins involved in DNA repair, cell death/growth induction, vascularization, and metabolism is inhibited or shifted toward other pathways by soluble mediators that orchestrate such change depending on the microenvironment conditions. In this chapter, we focus on the antithetic properties that proteins could exert, depending on the microenvironment that orchestrates the complex networks among proteins and their respective partners. © 2008 Elsevier B.V. All rights reserved

Frequency doubling in the cyanobacterial circadian clock

Organisms use circadian clocks to generate 24-h rhythms in gene expression. However, the clock can interact with other pathways to generate shorter period oscillations. It remains unclear how these different frequencies are generated. Here, we examine this problem by studying the coupling of the clock to the alternative sigma factor $\textit{sigC}$ in the cyanobacterium $\textit{Synechococcus elongatus}$. Using single-cell microscopy, we find that $\textit{psbAI}$, a key photosynthesis gene regulated by both $\textit{sigC}$ and the clock, is activated with two peaks of gene expression every circadian cycle under constant low light. This two-peak oscillation is dependent on $\textit{sigC}$, without which $\textit{psbAI}$ rhythms revert to one oscillatory peak per day. We also observe two circadian peaks of elongation rate, which are dependent on $\textit{sigC}$, suggesting a role for the frequency doubling in modulating growth. We propose that the two-peak rhythm in $\textit{psbAI}$ expression is generated by an incoherent feedforward loop between the clock, $\textit{sigC}$ and $\textit{psbAI}$. Modelling and experiments suggest that this could be a general network motif to allow frequency doubling of outputs.This research was made possible by the award of a European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement 338060. The work in the Locke laboratory is further supported by a fellowship from the Gatsby Foundation (GAT3272/GLC) and a Fellowship from the Human Frontier Science Program (CDA00068/2012)

EFFECT OF ACTIVATORS SOLUTION ON MOTILITY AND FERTILIZATION OF FROZEN BLACK SHARK, LABEO CHRYSOPHEKADION SPERMATOZOA

ABSTRACT In freshwater teleost, the spermatozoa are immotile in the testis and seminal plasma. The difference in osmolality between seminal plasma and external water is an important regulatory factor of sperm motility in many fish species. The initiation of sperm motility is triggered by increasing osmolality in marine fish or by decreasing osmolality in freshwater fish. Modified extender +DMSO (10%) and MC+DMSO (15%) were used to cryopreserve black shark, Labeo chrysophekadion sperm. Five activators solution (Tap water, 17mM NaCl+5 mM Tris-HCl, 0.3% NaCl, 100 mM KCl+20 mM Tris-HCl and SAS (50 mM NaCl+30 mM KCl+30 mM Tris-HCl) were used to examine the feasibility of activations solution of frozen black shark sperm. The highest percentage of motility (74%) fertilization (50%) and has a long time motile spermatozoa 61 s (P<0.05) was resulting from 0.3% NaCl as activator. Which has a lower osmotic pressure (96 mOsm kg-1) than that of frozen spermatozoa of black shark (251 mOsm kg-1). The present study found that increasing osmolality in 100 mM KCl+20 mM Tris-HCl (230 mOsm kg-1) and SAS (191 mOsm kg-1) solutions were decreasing in motility and fertilization percentages of black shark frozen sperm