Outline Of Head Research Articles

A new passalid fossil (Insecta: Coleoptera) from the Santana Formation (Crato member, Lower Cretaceous), Araripe Basin, NE Brazil: Paleoecological and paleobiogeographic implications

Species with a xylobiont lifestyle (e.g., inside fallen tree trunks) are rarely fossilized because of their taphonomic peculiarities. Reconstructing the evolutionary history of these lineages is challenging, especially with respect to dating major events. Here, a new genus and species of Passalidae, Protopassalus araripensis gen. et sp. nov., is described based on a well-preserved fossil in laminated limestone from the Crato Formation (Santana Group, Lower Cretaceous, upper Aptian), collected in a quarry near Nova Olinda, Chapada do Araripe, State of Ceará, Brazil. This specimen is the oldest passalid fossil and the first record for the family in the Santana Group, and aids in understanding the origin and radiation of terrestrial Coleoptera. Protopassalus araripensis gen. et sp. nov. shows characteristics of the subfamily Passalinae, representing the oldest record of this group and suggesting that the family emerged over 150 Ma. The new genus is attributed to this subfamily based on: outline of head and eyes with strongly convex frontal area, posteriorly grooved and curve, with incomplete central tubercle; pronotum rounded at sides with longitudinal groove; mesothorax with narrowing connection with abdomen, dorsally evident; elytra longitudinally striated and with similar dorsal striae and interstriae. We propose a new sequence of events in the Passalidae paleobiogeography, as a basis to evaluate other organisms of low dispersal ability.

Video-Assisted Navigation for Adjustment of Image-Guidance Accuracy to Slight Brain Shift.

Information supplied by an image-guidance system can be superimposed on the operating microscope oculars or on a screen, generating augmented reality. Recently, the outline of a patient's head and skull, injected in the oculars of a standard operating microscope, has been used to check the registration accuracy of image guidance. To propose the use of the brain surface relief and superficial vessels for real-time intraoperative visualization and image-guidance accuracy and for intraoperative adjustment for brain shift. A commercially available image-guidance system and a standard operating microscope were used. Segmentation of the brain surface and cortical blood vessel relief was performed manually on preoperative computed tomography and magnetic resonance images. The overlay of segmented digital and real operating-microscope images was used to monitor image-guidance accuracy. Adjustment for brain shift was performed by manually matching digital images on real structures. Experimental manipulation on a phantom proved that the brain surface relief could be used to restore accuracy if the primary registration shifted. Afterward, the technique was used to assist during surgery of 5 consecutive patients with 7 deep-seated brain tumors. The brain surface relief could be successfully used to monitor registration accuracy after craniotomy and during the whole procedure. If a certain degree of brain shift occurred after craniotomy, the accuracy could be restored in all cases, and corticotomies were correctly centered in all cases. The proposed method was easy to perform and augmented image-guidance accuracy when operating on small deep-seated lesions.

Mutually pumped phase-conjugate mirror: fish-head configuration

A new mutually pumped phase-conjugate mirror configuration is demonstrated in barium titanate crystals, in which the beams travel in a geometrical path similar to the outline of a fish's head. This configuration has a fast (~1-s) response time, for input beam powers of 56 mW, after which a stable phase-conjugate reflectivity of ~28% is attained. The tolerance of the output to both angular and positional misalignment is assessed. Two detailed images were simultaneously phase conjugated, and it was found that 125-microm features could be clearly resolved without cross talk. We tentatively suggest possible mechanisms for this configuration.