IPhone 4 models. In fall 2010, pentalobe screws started to replace the Philips screws used in post-repair units in the US and in production units in Japan. The iPhone 4 shipped with iOS 4, which was the newest version of Apple's iOS mobile operating system at the time. iOS 4 introduced a multitasking system, allowing apps to remain "suspended" in memory, perform certain operations in the background, and allowing users to switch between apps using an on-screen menu. It also introduced FaceTime, which allows users to perform video calls between other iPhone, iPad, iPod Touch, and OS X users. The iPhone 4
JUNQ and IPOD IPOD may serve not only as a sequestration site, but also as a functional compartment. The IPOD is a non- membrane bound cellular site, which in yeast is located by the vacuole. FRAP and FLIP assays revealed that proteins in the IPOD are tightly packed, in-soluble and don't exchange with the cytosol. Amyloidogenic proteins, such as the Huntingtin protein, are the IPOD's substrates. Misfolded proteins must be non-ubiquitinated to be sorted to the IPOD. Ubiquitination of an otherwise IPOD substrate, such as the RNQ1 fungal prion, will result in its sequestration in the JUNQ inclusion. Upon accumulation of misfolded proteins,