UBS dampened the mood in pharmaceuticals and biotechnology, meaning that the sector fell to the bottom of the pile on Friday.UBS Investment Research cut its rating on the European pharmaceutical sector to "neutral" from "small overweight," saying the defensive sector that benefited from the economic soft patch and the sovereign debt crisis, will be hit by the turnaround in these lead indicators. Shares in drugs giant AstraZeneca and GlaxoSmithKline (GSK) fell lower on the comments. Astra was 1.29% down at 3,052p at 16:27, while GSK fell 0.15% to 1,338.5p.The industrial metals and mining sector, however, was the best performing sector after some strong drilling update from two constituents.Botswana-focused miner Discovery Metals is in demand after "encouraging drilling results" confirmed copper and silver mineralisation in the Mid Kalahari Zone. Shares rose 2.34% to 87.50p.Bellzone Mining was 0.62% higher at 40.25p following its annual general meeting, which reported that the company's Forécariah project in the Republic of Guinea is on schedule to achieve production of iron ore in the first quarter of 2012.Finland-focused nickel and zinc miner Talvivaara was also providing a lift to the sector, rising 4.2% to trade at 427.20p.BCTop performing sectors so far todayIndustrial Metals & Mining 7,641.67 +2.86%Industrial Engineering 7,664.75 +1.93%Travel & Leisure 4,610.58 +1.74%Mobile Telecommunications 3,735.86 +1.64%Construction & Materials 3,807.36 +1.56%Bottom performing sectors so far todayPharmaceuticals & Biotechnology 9,575.01 -0.42%Personal Goods 24,971.75 -0.37%Health Care Equipment & Services 3,719.07 -0.35%Life Insurance 4,311.89 -0.27%Oil Equipment, Services & Distribution 25,685.39 -0.27%