Altruism, Altruistic Punishment and Social Investment

The concept of altruism is used in very different forms by computer scientists,economists, philosophers, social scientists, psychologists and biologists. Yet, in order to be useful in social simulations, the concept "altruism" requires a more precise meaning. A quantitative formulation is proposed here, based on the cost/benefit analysis of the altruist and of society at large. This formulation is applied in the analysis of the social dynamic working of behaviors that have been called "altruistic punishments", using the agent based computer model Sociodynamica. The simulations suggest that "altruistic punishment" on its own cannot maintain altruistic behaviors. "Altruistic behavior" is sustainable in the long term only if these behaviors trigger synergetic forces in society that eventually make them produce benefits to most individuals. The simulations suggest however that "altruistic punishment" may work as a "social investment", and is thus better called "decentralized social punishment". This behavior is very efficient in enforcing social norms. The efficiency of decentralized social punishment in enforcing norms was dependent on the type of labor structured of the virtual society. I conclude that what is called "altruistic punishment" emerges as a type of social investment that can evolve either through individual and/or group selection, as a successful device for changing or enforcing norms in a society. Social simulations will help us in better understanding the underlying dynamic working of such devices.     

Effects of prostaglandins on the affinity of hemoglobin for oxygen in human whole blood in vitro

The effect of prostaglandin on the affinity of hemoglobin for oxygen was tested on human blood $\text{in vitro}$, using six different prostaglandins at several dosage levels in fresh heparinized blood from normal donors and in stored citrated blood, and using prostaglandin E₂ on the blood from four seriously ill patients. No significant alterations in the affinity of hemoglobin for oxygen were dtected. A very small decrease in oxygen affinity in stored blood with high doses of prostaglandin was not statistically significant and would be of no physiologic significance even if real.We conclude that under the circumstances of this experiment prostaglandins do not alter the affinity of hemoglobin for oxygen in human whole blood $\text{in vitro}$.     

Carbamazepine produces nonspecific effects on cocaine self-administration in rats.

Anecdotal evidence in humans suggest that carbamazepine suppresses cocaine-induced rush and craving. Such claims are unsupported in controlled trials using a placebo control. In the present study, rats were trained to self-administer i.v. cocaine in daily 2-hr sessions in which every tenth lever press delivered 1 mg/kg cocaine. After responding was stable, they were injected before each session with the vehicle for 2 days followed by carbamazepine for 2 days. At a 7 mg/kg dose, carbamazepine was without effect, whereas 15 mg/kg suppressed responding for cocaine only on the second (day 4) day of carbamazepine treatment. With 4 consecutive days of treatment, carbamazepine (15 mg/kg) reduced cocaine-maintained responding slightly, but significantly. In another group of animals trained to lever-press for food reinforcement, carbamazepine (15 mg/kg) also significantly decreased the rate of responding, suggesting that the suppression of responding was not specific to cocaine-reinforced behavior.     

Tetradecanoyl phorbol acetate stimulates latent collagenase production by cultured human endothelial cells

Angiogenesis is associated with the fragmentation of blood vessel basement membranes. Since collagen is a major constituent of basement membranes, cultured human endothelial cells derived from umbilical cord veins were assayed for their ability to produce collagenase. Unstimulated cultured human endothelial cells did not secrete detectable levels of active collagenase into the culture medium. However, if the post-culture medium was treated with trypsin or plasmin, low levels of collagenolytic activity were detected, indicating that endothelial cells secrete small amounts of latent collagenase. Addition of the tumor promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA) to the culture medium stimulated the secretion of collagenase by endothelial cells 5–30 fold. More than 90% of the collagenase was secreted in the latent form. Stimulation of collagenase production was detected at 10^?9 M TPA and was maximal at 10^?8 M TPA. An increase in the rate of collagenase production could be detected within 3 hr after the addition of TPA, and full induction occurred by 12 hr. Cycloheximide (3 μg/ml) or actinomycin D (0.1 μg/ml) inhibited both basal levels of collagenase production and the stimulation of collagenase production by TPA. Phorbol-12,13-didecanoate (PDD), a tumor-promoting analog of TPA, also stimulated collagenase production when administered at the same concentrations that were effective for TPA. However, 4-O-methyl TPA and 4-αPDD, two analogs of TPA which are not tumor promoters, did not stimulate collagenase production at concentrations up to 10^?7 M. The collagenase produced by endothelial cells was a typical vertebrate collagenase as judged by the following criteria: it cleaved collagen into only two fragments which were three quarters and one quarter of the length of the intact molecule; it was inhibited by EDTA and human serum; it was not inhibited by inhibitors of serine, thiol or aspartate proteases. Thus TPA causes an increase in the production of latent collagenase by cultured human endothelial cells.     

The activation wave of calcium in the ascidian egg and its role in ooplasmic segregation

We have studied egg activation and ooplasmic segregation in the ascidian Phallusia mammillata using an imaging system that let us simultaneously monitor egg morphology and calcium-dependent aequorin luminescence. After insemination, a wave of highly elevated free calcium crosses the egg with a peak velocity of 8-9 microns/s. A similar wave is seen in egg fertilized in the absence of external calcium. Artificial activation via incubation with WGA also results in a calcium wave, albeit with different temporal and spatial characteristics than in sperm-activated eggs. In eggs in which movement of the sperm nucleus after entry is blocked with cytochalasin D, the sperm aster is formed at the site where the calcium wave had previously started. This indicates that the calcium wave starts where the sperm enters. In 70% of the eggs, the calcium wave starts in the animal hemisphere, which confirms previous observations that there is a preference for sperm to enter this part of the egg (Speksnijder, J. E., L. F. Jaffe, and C. Sardet. 1989. Dev. Biol. 133:180-184). About 30-40 s after the calcium wave starts, a slower (1.4 microns/s) wave of cortical contraction starts near the animal pole. It carries the subcortical cytoplasm to a contraction pole, which forms away from the side of sperm entry and up to 50 degrees away from the vegetal pole. We propose that the point of sperm entry may affect the direction of ooplasmic segregation by causing it to tilt away from the vegetal pole, presumably via some action of the calcium wave.     

Saikosaponin-d,a novel SERCA inhibitor,induces autophagic cell death in apoptosis-defective cells

Autophagy is an important cellular process that controls cells in a normal homeostatic state by recycling nutrients to maintain cellular energy levels for cell survival via the turnover of proteins and damaged organelles. However, persistent activation of autophagy can lead to excessive depletion of cellular organelles and essential proteins, leading to caspase-independent autophagic cell death. As such, inducing cell death through this autophagic mechanism could be an alternative approach to the treatment of cancers. Recently, we have identified a novel autophagic inducer, saikosaponin-d (Ssd), from a medicinal plant that induces autophagy in various types of cancer cells through the formation of autophagosomes as measured by GFP-LC3 puncta formation. By computational virtual docking analysis, biochemical assays and advanced live-cell imaging techniques, Ssd was shown to increase cytosolic calcium level via direct inhibition of sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase pump, leading to autophagy induction through the activation of the Ca²⁺/calmodulin-dependent kinase kinase–AMP-activated protein kinase–mammalian target of rapamycin pathway. In addition, Ssd treatment causes the disruption of calcium homeostasis, which induces endoplasmic reticulum stress as well as the unfolded protein responses pathway. Ssd also proved to be a potent cytotoxic agent in apoptosis-defective or apoptosis-resistant mouse embryonic fibroblast cells, which either lack caspases 3, 7 or 8 or had the Bax-Bak double knockout. These results provide a detailed understanding of the mechanism of action of Ssd, as a novel autophagic inducer, which has the potential of being developed into an anti-cancer agent for targeting apoptosis-resistant cancer cells.     

Self seeks like: many humans choose their dog pets following rules used for assortative mating

Theoretical and experimental studies suggest that mating and pair formation are not likely to be random. Assortative mating, characterized as self seeking like, seems to be widely practiced in nature. Experimental evidence for it is strong among humans seeking a mate. Assortative mating increases the probability of finding a genetically similar mate, without fomenting inbreeding, achieving assortative mating without hindering the working of other mate-selection strategies that aim to maximize the search for good genes, optimizing the working of sex in evolutionary terms. Self seeking like seems to be a behavioural inborn trait among humans, and here we present evidence that the same behavioural mechanism seems to be at work when humans choose a pet. We show that in a significant proportion of human–pet pairs, sampled in pet beauty contests, the partners show much higher facial resemblances than can be expected by random pair formation.     

Physiological Studies on Pea Tendrils. II. The Role of Light and ATP in Contact Coiling

Excised pea (Pisum sativum L.) tendrils incubated in the light coil more than those incubated in the dark. This light effect, which displays spectral responses characteristic of chlorophyll-mediated mechanisms, is increased by at least 8 hours of prior dark incubation of plants from which the tendrils were derived. Considerable evidence indicates a major role of ATP in coiling. For example, inhibitors of ATP production decrease contact coiling. Exogenous ATP increases curvature in the dark, whereas exogenous adenosine, AMP and ADP are practically without effect. The ATP effect can be reversed by the addition of sucrose to the bathing solution. Tendrils of plants placed in the dark overnight have lower ATP levels than those held in the light. One half hour after stimulation, the endogenous ATP level of tendrils on plants kept in the light decreased fourfold. In the same period, the endogenous inorganic phosphate level increased markedly, indicating high adenosine triphosphatase activity.