human activities are more likely to affect the habitat in areas of permanent water (oases) or where water comes close to the surface. Here, the local pressure on natural resources can be intense. The remaining populations of large mammals have been greatly reduced by hunting for food and recreation. In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization.
What kind of pressure can be intense in the Sahara?
natural resources

The majority of studies indicate antibiotics do interfere with contraceptive pills, such as clinical studies that suggest the failure rate of contraceptive pills caused by antibiotics is very low (about 1%). In cases where antibacterials have been suggested to affect the efficiency of birth control pills, such as for the broad-spectrum antibacterial rifampicin, these cases may be due to an increase in the activities of hepatic liver enzymes' causing increased breakdown of the pill's active ingredients. Effects on the intestinal flora, which might result in reduced absorption of estrogens in the colon, have also been suggested, but such suggestions have been inconclusive and controversial. Clinicians have recommended that extra contraceptive measures be applied during therapies using antibacterials that are suspected to interact with oral contraceptives.
What do physicians recommend to counteract this potential issue?
extra contraceptive measures

Hayek’s concept of the market as a spontaneous order has been recently applied to ecosystems to defend a broadly non-interventionist policy. Like the market, ecosystems contain complex networks of information, involve an ongoing dynamic process, contain orders within orders, and the entire system operates without being directed by a conscious mind. On this analysis, species takes the place of price as a visible element of the system formed by a complex set of largely unknowable elements. Human ignorance about the countless interactions between the organisms of an ecosystem limits our ability to manipulate nature. Since humans rely on the ecosystem to sustain themselves, we have a prima facie obligation to not disrupt such systems. This analysis of ecosystems as spontaneous orders does not rely on markets qualifying as spontaneous orders. As such, one need not endorse Hayek’s analysis of markets to endorse ecosystems as spontaneous orders.
What is the term used to describe the obligation for humans to avoid disrupting the ecosystem?
prima facie