Coral snake mimicry: does it occur?

Field observations and experimental evidence refute previous objections to the coral snake mimicry hypothesis. Concordant color pattern variation spanning hundreds of miles and several presumed venomous models strongly suggests that several harmless or mildly venomous colubrid snakes are indeed mimics of highly venomous elapids.     

The federal deficit: how does it matter?

Government deficits and debt are surpluses and assets of the private sector of the economy that stimulate private spending. Official measures of deficits are misleading, however, for failing to distinguish public investment from current spending and for failing to adjust for inflation. Correctly measured real deficits have contributed to the growth of gross national product, consumption, and imports, and to investment as well. Optimal policy consistent with balanced growth calls not for elimination of the nominal deficit but rather for prudent deficit reduction accompanied by and stemming at least partly from sufficient monetary stimulus to achieve and sustain relatively full employment.     

Growing up in poor neighborhoods: how much does it matter?

This article is a review of research on how much the life chances of children are affected by the socioeconomic and racial mix of their schools and neighborhoods. The social mix of a high school has little effect on students' chances of attending college or on white students' academic achievement. Evidence about the effect of the socioeconomic mix of schools or neighborhoods on achievement of elementary school students, on graduation rates of high school students, on teenage crime, and on early labor market experience is weak. Growing up in poor neighborhoods seems to increase black teenage pregnancy rates.     

What is artiifcial meat and what does it mean for the future of the meat industry?

The meat industry cannot respond to increases in demand by ever increasing resource use. The industry must ifnd solutions to issues regarding animal welfare, health and sustainability and wil have to d...     

What is artificial meat and what does it mean for the future of the meat industry?

The meat industry cannot respond to increases in demand by ever increasing resource use. The industry must find solutions to issues regarding animal welfare, health and sustainability and will have to do so in the face of competition from emerging non-traditional meat and protein products in an increasingly complex regulatory environment. These novel meat and protein products, otherwise known as ‘artificial meat' are utilising ground breaking technologies designed to meet the issues facing the conventional meat industry. These artificial meats, in vitro or cultured meat and meat from genetically modified organisms have no real capacity to compete with conventional meat production in the present environment. However, meat replacements manufactured from plant proteins and mycoproteins are currently the biggest competitors and are gaining a small percentage of the market. Manufactured meats may push conventional meat into the premium end of the market, and supply the bulk, cheap end of the market if conventional meat products become more expensive and the palatability and versatility of manufactured meats improve. In time the technology for other artificial meats such as meat from genetic modified organisms or cultured meat may become sufficiently developed for these products to enter the market with no complexity of the competition between meat products. Conventional meat producers can assimilate agroecology ecology concepts in order to develop sustainable animal production systems. The conventional meat industry can also benefit from assimilating biotechnologies such as cloning and genetic modification technologies, using the technology to adapt to the changing environment and respond to the increasing competition from artificial meats. Although it will depend at least partly on the evolution of conventional meat production, the future of artificial meat produced from stem cells appears uncertain at this time.     

Why does the Earth spin forward?

The spins of the terrestrial planets likely arose as the planets formed by the accretion of planetesimals. Depending on the masses of the impactors, the planet's final spin can either be imparted by many small bodies (ordered accretion), in which case the spin is determined by the mean angular momentum of the impactors, or by a few large bodies (stochastic accretion), in which case the spin is a random variable whose distribution is determined by the root-mean-square angular momentum of the impactors. In the case of ordered accretion, the planet's obliquity is expected to be near 0 degrees or 180 degrees , whereas, if accretion is stochastic, there should be a wide range of obliquities. Analytic arguments and extensive orbital integrations are used to calculate the expected distributions of spin rate and obliquity as a function of the planetesimal mass and velocity distributions. The results imply that the spins of the terrestrial planets are determined by stochastic accretion.