A dome camera includes an inner cover covering a camera lens and a semi-spherical outer cover covering the inner cover, the camera lens being rotatable in a tilt direction and in a pan direction. The clock deskew circuitry, at the receiver side, receives data signals and a forwarded clock signal from a transmitter. Preferably, a ventilation valve is also actuated the movable part. Each packet flow is mapped to a corresponding virtual tunnel end point that distributes each packet of the packet flow. This, as a result, allows the refrigeration apparatus to operate at a COP close to an ideal condition. In more specific embodiments, a ligation involves reacting a first peptide having a protected cysteyl group at its N-terminal and a phenylthioester at its C-terminal with a second peptide having a cysteine residue at its N-termini and a thioester at its C-termini to form a ligation product.