Oregon’s once-shiny season has taken a huge smudge, and the Ducks will attempt to snap a five-game losing streak when they face Northwestern in Big Ten play on Tuesday night at Eugene, Ore.Oregon was ranked No. 15 in the Associated Press Top 25 before its slide began. The troubles have been so pronounced that the Ducks are now tied for 11th in the Big Ten.However, Oregon (16-8, 5-8) has a chance to get back on the winning track considering Northwestern (13-11, 4-9) stands 0-7 on the road. The Wildcats also have lost senior guards Brooks Barnhizer (foot) and Jalen Leach (ACL) for the season.Still, nothing is coming easy for the Ducks, who lost 86-74 Saturday at No. 11 Michigan State.Talk about a tale of two halves. Oregon scored 50 points in the first half and led by 14 at the break. In the second half, the Ducks allowed 50 points and were outscored by 26.”I’m not sure who was coaching that team in the second half. But he did an awful job, I know that,” said Ducks coach Dana Altman, taking the blame.Oregon made 10 of 19 3-pointers in the first half before missing all eight 3-point attempts in the second half. Altman liked the defensive play even less.”I was much more pleased with our defensive activity the first half, when I just thought we were really active,” Altman said. “But when they punched us that second half, our activity went down. And they kind of got whatever they wanted.”Jackson Shelstad scored 18 of his team-high 22 points in the first half. He leads Oregon with a 12.9 scoring average.