Hidden Effects of Chronic Tuberculosis in African Buffalo

Infectious diseases can bring about population declines and local host extinctions, contributing significantly to the global biodiversity crisis. Nonetheless, studies measuring population-level effects of pathogens in wild host populations are rare, and taxonomically biased toward avian hosts and macroparasitic infections. We investigated the effects of bovine tuberculosis (bTB), caused by the bacterial pathogen Mycobacterium bovis, on African buffalo (Syncerus caffer) at Hluhluwe-iMfolozi Park, South Africa. We tested 1180 buffalo for bTB infection between May 2000 and November 2001. Most infections were mild, confirming the chronic nature of the disease in buffalo. However, our data indicate that bTB affects both adult survival and fecundity. Using an age-structured population model, we demonstrate that the pathogen can reduce population growth rate drastically; yet its effects appear difficult to detect at the population level: bTB causes no conspicuous mass mortalities or fast population declines, nor does it alter host-population age structure significantly. Our models suggest that this syndrome—low detectability coupled with severe impacts on population growth rate and, therefore, resilience—may be characteristic of chronic diseases in large mammals.

Differences between Tethered Polyelectrolyte Chains on Bare Mica and Hydrophobically Modified Mica

This study investigates the structures of layers of amphiphilic diblock copolymers of poly(t-butyl styrene)-poly- (styrene sulfonate) (PtBS-PSS) adsorbed on both the bare mica surface (hydrophilic) and an octadecyltriethoxysilane (OTE)-modified mica surface (hydrophobic). When the surface is rendered hydrophobic, the nonsoluble block exhibits stronger interaction with the surface and higher adsorbed masses are achieved. Interaction forces between two such adsorbed layers on both substrates were measured using the surface forces apparatus. The effect of salt concentration (Cs) and molecular weight (N) on the height of the self-assembled layers (L0) was examined in each case. The resulting scaling relationship is in good agreement with predictions of the brush model, L0 ∞ N1.0 in the low-salt limit and L0N-1 ∞ (Cs/σ)-0.32 in the salted regime, when adsorption takes place onto the hydrophobized mica surface. For adsorption on the bare mica surface, L0N-0.7 ∞ Cs -0.17 agrees with the scaling prediction of the sparse tethering model. The results suggest that, on the hydrophilic bare mica surface, the adsorbed amount is not high enough to form a brush structure and only very little intermolecular stretching of the tethered chains occurs; in contrast, the presence of the hydrophobic OTE layer increases the tethering density such that the polyelectrolyte chains adopt a brush conformation.

World of Unknown Creatures and Their Hidden Works

What is the most mysterious feelings in mankind? What is the most general way by which every mankind is subject to change. Well monotonous, and steady life where someone does the same kind of work at same pace in same time, without any change of events, creates the burdensome feeling in a person. Yet people are unaware of it. We don't know where are we going, yet we go at the same pace, since in practical sense we are getting some credit for something. But the thing how much do we keep up, and maintain the balance in nature, so that we can really feel the value and the quality of life, and know the exact happiness of fulfilling the work. But if its totally becomes materialistic, and emotional aspect goes away from human beings, where social talking never goes away from your duties. Then!!!! ... I mean there is no need of human beings. If we are so developed, right from past few centuries and our domination, had created a modern social world, then we can create all kinds of devices and software which can handle all the works for which the people don't have to stay overtime just to finish that. I mean in that way human life will move through some progress, and will have some development. But the environment where we are living nothing new or development is taking place as the work becomes a duty for human being but not to machine which should be given some task to be completed.So all those devices are not in the society, since human being is already taking charge if it.