Appraising the combustion of biogas for sustainable rural energy needs

This paper shows the combustion of biogas in rural households’ appliances. Biogas has been known since 1800s as an odourless and colourless gas with high combustion rate. Its use is beginning to gain ground in most developing countries like Nigeria due to its availability, ease of generation and environmental friendliness. Developing countries are characterized by poor infrastructural development, inadequate energy and water supply, poor health delivery system, etc. which hinders economic and social development. Most sources of rural households’ energy are firewood, animal dung, crop residue and kerosene which are associated with negative environmental impacts. The study was carried-out by articulation of past literatures on biogas combustion and consumption in household’s appliances and internal combustion engines. The study ascertains from the past studies high efficiency of biogas compared with natural gas and liquid petroleum gas (LPG) on stove-top burner, oven and two panel flue heater. It was observed that, biogas consumption is higher in all the appliances under investigation as compared to natural gas and LPG. The study recommended public enlightenment on biogas technology and its associate benefits to rural areas. The government and NGOs should encourage the application of this technology through financing of pilot projects in community leaders’ households which will extend to the populace. The technology should also be embraced because it is associated with environmental hygiene.Key words: Efficiency, hygiene, sustainability, developing countries, biogas

A Universal Model of Global Civil Unrest

Civil unrest is a powerful form of collective human dynamics, which has led to major transitions of societies in modern history. The study of collective human dynamics, including collective aggression, has been the focus of much discussion in the context of modeling and identification of universal patterns of behavior. In contrast, the possibility that civil unrest activities, across countries and over long time periods, are governed by universal mechanisms has not been explored. Here, we analyze records of civil unrest of 170 countries during the period 1919-2008. We demonstrate that the distributions of the number of unrest events per year are robustly reproduced by a nonlinear, spatially extended dynamical model, which reflects the spread of civil disorder between geographic regions connected through social and communication networks. The results also expose the similarity between global social instability and the dynamics of natural hazards and epidemics.Comment: 8 pages, 3 figure

A prophylactic vaccine for breast cancer?

Cancer vaccines are the Holy Grail for patients and clinicians alike. The possibility that we can be vaccinated against common cancers is very appealing and the socioeconomic consequences are significant. A recent paper from Vincent Tuohy's group, published in the journal Nature Medicine, suggests a new approach for the development of a prophylactic vaccine for breast cancer. Their strategy was to induce mammary gland failure in mice by immunisation with an antibody specific to a milk protein that resulted in autoimmunity during lactation. This also showed some efficacy as a therapeutic vaccine. Can we look forward to the elimination of breast cancer

How large should whales be?

The evolution and distribution of species body sizes for terrestrial mammals is well-explained by a macroevolutionary tradeoff between short-term selective advantages and long-term extinction risks from increased species body size, unfolding above the 2g minimum size induced by thermoregulation in air. Here, we consider whether this same tradeoff, formalized as a constrained convection-reaction-diffusion system, can also explain the sizes of fully aquatic mammals, which have not previously been considered. By replacing the terrestrial minimum with a pelagic one, at roughly 7000g, the terrestrial mammal tradeoff model accurately predicts, with no tunable parameters, the observed body masses of all extant cetacean species, including the 175,000,000g Blue Whale. This strong agreement between theory and data suggests that a universal macroevolutionary tradeoff governs body size evolution for all mammals, regardless of their habitat. The dramatic sizes of cetaceans can thus be attributed mainly to the increased convective heat loss is water, which shifts the species size distribution upward and pushes its right tail into ranges inaccessible to terrestrial mammals. Under this macroevolutionary tradeoff, the largest expected species occurs where the rate at which smaller-bodied species move up into large-bodied niches approximately equals the rate at which extinction removes them.Comment: 7 pages, 3 figures, 2 data table

Prophylactic HPV vaccines: prospects for eliminating ano-genital cancer

Virtually all cases of cervical cancer and its precursor intra-epithelial lesions are a result of infection with one or other of a subset of genital human papillomaviruses (HPVs), suggesting that prevention of HPV infection by prophylactic vaccination would be a highly effective anticancer strategy. Two HPV L1 virus-like particle vaccines have been developed, a quadrivalent HPV16/18/6/11 product and a bivalent HPV16/18 product; both have been shown to be highly immunogenic with a good safety profile and 100% efficacy against HPV16/18-related high-grade cervical intra-epithelial neoplasia (CIN2/3), implying that they will be effective at preventing HPV16/18-related cervical cancer

On products of long cycles: short cycle dependence and separation probabilities

We present various results on multiplying cycles in the symmetric group. One result is a generalisation of the following theorem of Boccara (1980): the number of ways of writing an odd permutation in the symmetric group on n symbols as a product of an n-cycle and an (n - 1)-cycle is independent of the permutation chosen. We give a number of different approaches of our generalisation. One partial proof uses an inductive method which we also apply to other problems. In particular, we give a formula for the distribution of the number of cycles over all products of cycles of fixed lengths. Another application is related to the recent notion of separation probabilities for permutations introduced by Bernardi, Du, Morales and Stanley (2014)

Functional diversity of marine ecosystems after the Late Permian mass extinction event

Article can be accessed from http://www.nature.com/ngeo/journal/v7/n3/full/ngeo2079.htmlThe Late Permian mass extinction event was the most severe such crisis of the past 500 million years and occurred during an episode of global warming. It is assumed to have had significant ecological impact, but its effects on marine ecosystem functioning are unknown and the patterns of marine recovery are debated. We analysed the fossil occurrences of all known Permian-Triassic benthic marine genera and assigned each to a functional group based on their inferred life habit. We show that despite the selective extinction of 62-74% of marine genera there was no significant loss of functional diversity at the global scale, and only one novel mode of life originated in the extinction aftermath. Early Triassic marine ecosystems were not as ecologically depauperate as widely assumed, which explains the absence of a Cambrian-style Triassic radiation in higher taxa. Functional diversity was, however, significantly reduced in particular regions and habitats, such as tropical reefs, and at these scales recovery varied spatially and temporally, probably driven by migration of surviving groups. Marine ecosystems did not return to their pre-extinction state, however, and radiation of previously subordinate groups such as motile, epifaunal grazers led to greater functional evenness by the Middle Triassic

Gradual phyletic evolution at the generic level in early Eocene omomyid primates

Analysis of dental morphology in over 600 stratigraphically controlled specimens of tarsier-like primates from early Eocene strata in Bighorn Basin, Wyoming, provides important new data for understanding the tempo and mode of evolution in primates

Cycles of Police Reform in Latin America.

yesOver the last quarter century post-conflict and post-authoritarian transitions in Latin America have been accompanied by a surge in social violence, acquisitive crime, and insecurity. These phenomena have been driven by an expanding international narcotics trade, by the long-term effects of civil war and counter-insurgency (resulting in, inter alia, an increased availability of small arms and a pervasive grammar of violence), and by structural stresses on society (unemployment, hyper-inflation, widening income inequality). Local police forces proved to be generally ineffective in preventing, resolving, or detecting such crime and forms of “new violence”3 due to corruption, frequent complicity in criminal networks, poor training and low pay, and the routine use of excessive force without due sanction. Why, then, have governments been slow to prioritize police reform and why have reform efforts borne largely “limited or nonexistent” long-term results? This chapter highlights a number of lessons suggested by various efforts to reform the police in Latin America over the period 1995-2010 . It focuses on two clusters of countries in Latin America. One is Brazil and the Southern Cone countries (Chile, Argentina, and Uruguay), which made the transition to democracy from prolonged military authoritarian rule in the mid- to late 1980s. The other is Central America and the Andean region (principally El Salvador, Guatemala, Honduras, Peru, and Colombia), which emerged/have been emerging from armed conflict since the mid- 1990s. The chapter examines first the long history of international involvement in police and security sector reform in order to identify long-run tropes and path dependencies. It then focuses on a number of recurring themes: cycles of de- and re-militarization of the policing function; the “security gap” and “democratization dilemmas” involved in structural reforms; the opportunities offered by decentralization for more community-oriented police; and police capacity to resist reform and undermine accountability mechanisms