Sometimes when Duke Gastiger is alone in his bar, the All American Rathskeller, he feels a presence. "It's never been a feeling of evil or goodness," Gastiger said. "It's just a feeling like someone or something else is there."Last night, 14 members of the Penn State Paranormal Research Society (PRS) conducted an investigation at the Rathskeller, 108 S. Pugh St., searching for what they called "abnormal activity."Paranormal Research Society President Ryan Buell said he thinks the bar has a certain "negative energy," but that does not mean there is something demonic or evil haunting the bar."Everyone carries their own energy," Buell said. "At a bar there's a lot of emotion, and people leave energy behind. We're going to find out what kind of energy is here and then go from there."Using infrared thermometers, microphones and audio and video recorders, PRS spent the evening searching for clues that would help them uncover if anything was lurking in the popular downtown bar."I don't think this has anything to do with Salvador Serrano," Buell said, referring to the 21-year-old who died in October 2003 in an altercation outside of the bar. "This bar has a lot of history, which in turn means a lot of energy. That doesn't mean there's a dead spirit sticking around."To conduct the investigation, the society divided into pairs of two, which were stationed throughout various parts of the bar, looking for information that would help them."We have thermometers that we use to look for temperature drops," Paranormal Research Investigator Amanda Kunkel said. "A drop in temperature can mean that a spirit is present."Kunkel said the team also uses digital cameras to pick up visual orbs and audio recordings to listen for voices.