Principles of the invention are directed to techniques for allowing a router forwarding packets within a computer network to perform two or more forwarding tree decisions per memory access. Also provided herein are vectors and host cells comprising those nucleic acid sequences, chimeric polypeptide molecules comprising the polypeptides of the present invention fused to heterologous polypeptide sequences, antibodies which bind to the polypeptides of the present invention and to methods for producing the polypeptides of the present invention. A distance from an imaging surface to the first group frame in the optical axis direction has a local minimum in the second section.