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Another effective way to decrease the transmission rate of infectious diseases is to recognize the effects of small-world networks. In epidemics, there are often extensive interactions within hubs or groups of infected individuals and other interactions within discrete hubs of susceptible individuals. Despite the low interaction between discrete hubs, the disease can jump to and spread in a susceptible hub via a single or few interactions with an infected hub. Thus, infection rates in small-world networks can be reduced somewhat if interactions between individuals within infected hubs are eliminated (Figure 1). However, infection rates can be drastically reduced if the main focus is on the prevention of transmission jumps between hubs. The use of needle exchange programs in areas with a high density of drug users with HIV is an example of the successful implementation of this treatment method. Another example is the use of ring culling or vaccination of potentially susceptible livestock in adjacent farms to prevent the spread of the foot-and-mouth virus in 2001.
What does recognizing the effects of small-world networks allow one to increase?
A: unanswerable

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Amensalism is the type of relationship that exists where one species is inhibited or completely obliterated and one is unaffected. This type of symbiosis is relatively uncommon in rudimentary reference texts, but is omnipresent in the natural world.[citation needed] There are two types of amensalism, competition and antibiosis. Competition is where a larger or stronger organisms deprives a smaller or weaker one from a resource. Antibiosis occurs when one organism is damaged or killed by another through a chemical secretion. An example of competition is a sapling growing under the shadow of a mature tree. The mature tree can begin to rob the sapling of necessary sunlight and, if the mature tree is very large, it can take up rainwater and deplete soil nutrients. Throughout the process the mature tree is unaffected. Indeed, if the sapling dies, the mature tree gains nutrients from the decaying sapling. Note that these nutrients become available because of the sapling's decomposition, rather than from the living sapling, which would be a case of parasitism.[citation needed] An example of antibiosis is Juglans nigra (black walnut), secreting juglone, a substance which destroys many herbaceous plants within its root zone.
What does the black walnut give out that kills plants?
A: juglone

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Testimony given to the Financial Crisis Inquiry Commission by Richard M. Bowen III on events during his tenure as the Business Chief Underwriter for Correspondent Lending in the Consumer Lending Group for Citigroup (where he was responsible for over 220 professional underwriters) suggests that by the final years of the U.S. housing bubble (20062007), the collapse of mortgage underwriting standards was endemic. His testimony stated that by 2006, 60% of mortgages purchased by Citi from some 1,600 mortgage companies were "defective" (were not underwritten to policy, or did not contain all policy-required documents) this, despite the fact that each of these 1,600 originators was contractually responsible (certified via representations and warrantees) that its mortgage originations met Citi's standards. Moreover, during 2007, "defective mortgages (from mortgage originators contractually bound to perform underwriting to Citi's standards) increased... to over 80% of production".
How many underwriters was Richard M. Bowen III responsible for at Citigroup?
A: 220

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What drove circadian rhythms to evolve has been an enigmatic question. Previous hypotheses emphasized that photosensitive proteins and circadian rhythms may have originated together in the earliest cells, with the purpose of protecting replicating DNA from high levels of damaging ultraviolet radiation during the daytime. As a result, replication was relegated to the dark. However, evidence for this is lacking, since the simplest organisms with a circadian rhythm, the cyanobacteria, do the opposite of this - they divide more in the daytime. Recent studies instead highlight the importance of co-evolution of redox proteins with circadian oscillators in all three kingdoms of life following the Great Oxidation Event approximately 2.3 billion years ago. The current view is that circadian changes in environmental oxygen levels and the production of reactive oxygen species (ROS) in the presence of daylight are likely to have driven a need to evolve circadian rhythms to preempt, and therefore counteract, damaging redox reactions on a daily basis.
What environmental event occurred 2.3 million years ago?
A:
Great Oxidation Event