On the negative side - the depletion of ocean resources as various fish varieties are harvested to near extinction, plus depletion of arable lands, either through development, or through agricultural practices that lead to erosion, salination (where the ground water and land become more salty), or simple loss of productivity through over use. Also, the use of inorganic fertilisers, pesticides and herbicides depletes the land over time. However positive efforts are being made with precision farming, sustainable agricultural practices, and more resistant crops to minimise the impacts. A related issue is the depletion of ground water used for irrigation, a problem in certain parts of the world, making crop irrigation technology a key factor in farming developments. The issue of genetically modified (GM) foods is also an issue that has its fair share of supporters and critics. There is considerable consumer concern over the impact of genetically modified food, and recent trials have generated much criticism and protest over concerns about the difficulty of containing the crops within the designated trial area and cross contamination allowing genetically modified foods into the food chain without proper regulation or control. In areas where GM foods are being produced, they are subject to regulation and control by the governing bodies. Part of the problem with acceptance is the public's general lack of understanding of the issues and related safety measures that are in place.

41 Why is a caesarean section recommended for the delivery of HIV-positive women?

42 Why is HIV not transmitted when delivering a baby through caesarean section?

43 1. Is HIV transmitted from mother to child during breastfeeding? 2. Is it possible to be infected with HIV through the ingestion of food and drinks contaminated with the virus?

44 Is it true that some patients are resistant to HIV infection despite repeated exposure to the virus?

45 With regard to live vaccination and HIV, can MMR be given to an HIV-positive baby?

46 In a patient with meningitis: can the development of digital gangrene of the thumbs and sudden dyspnoea with a respiratory rate of 40/min, with intercostal, subcostal and suprasternal withdrawal, be attributed to disseminated intravascular coagulation (DIC)?

47 1. What are the causes of anaemia in HIV infection? 2. What are the measures necessary to prevent the transfusion of HIV-infected blood to an individual (please explain in light of the window period)?

48 What is the recommended treatment for pulmonary anthrax?

49 What primary or specific tests should be performed before giving a patient primaquine for the treatment of relapsing malaria?

50 How sensitive is the polymerase chain reaction (PCR) test for herpes simplex virus 1 (HSV-1) in the cerebrospinal fluid (CSF) for confirming the diagnosis of HSV-1 encephalitis? And is herpes simplex virus 2 (HSV-2) usually tested for as well?