Molecular fingerprints resolve affinities of Rhynie chert organic fossils.

The affinities of extinct organisms are often difficult to resolve using morphological data alone. Chemical analysis of carbonaceous specimens can complement traditional approaches, but the search for taxon-specific signals in ancient, thermally altered organic matter is challenging and controversial, partly because suitable positive controls are lacking. Here, we show that non-destructive Fourier Transform Infrared Spectroscopy (FTIR) resolves in-situ molecular fingerprints in the famous 407 Ma Rhynie chert fossil assemblage of Aberdeenshire, Scotland, an important early terrestrial Lagerstätte. Remarkably, unsupervised clustering methods (principal components analysis and K-mean) separate the fossil spectra naturally into eukaryotes and prokaryotes (cyanobacteria). Additional multivariate statistics and machine-learning approaches also differentiate prokaryotes from eukaryotes, and discriminate eukaryotic tissue types, despite the overwhelming influence of silica. We find that these methods can clarify the affinities of morphologically ambiguous taxa; in the Rhynie chert for example, we show that the problematic "nematophytes" have a plant-like composition. Overall, we demonstrate that the famously exquisite preservation of cells, tissues and organisms in the Rhynie chert accompanies similarly impressive preservation of molecular information. These results provide a compelling positive control that validates the use of infrared spectroscopy to investigate the affinity of organic fossils in chert.

Subspecialty training: does it affect the outcome of women treated for a gynecologic malignancy?

A review of available direct and indirect scientific reports strongly suggests that subspecialty training increases the likelihood that the appropriate surgical procedure will be completed in women operated on for gynecologic cancer. It is likely that specialty care lessens the costs associated with diagnosis, treatment and surveillance, and frequently improves survival.

A new arthropod from the Silurian Konservat-Lagerstätte of Herefordshire, UK.

A small, non-biomineralized, macrophagous arthropod with chelicerate affinities, Offacolus kingi gen. et sp. nov., from the Silurian (Wenlock Series) of Herefordshire, UK, is described. The dorsal exoskeleton comprises an arch-like cephalic shield, a thorax of three free tergites and a triangular posterior tagma of five fused tergites, the last with a stout postero-dorsally directed medial spine. Seven pairs of appendages beneath the cephalic shield surround a postero-medially sited oral cavity on the ventral surface of the head. Appendages I and, probably II are uniramous and project antero-ventrally; I was sensory and II sensory and/or ambulatory. Appendages III-VI are biramous, each with an antero-ventrally projecting ramus and a robust, highly geniculate, horizontally oriented ramus that projects through an anterior gape. The former rami were ambulatory and the latter have spinose terminal podomeres and functioned as a unit for trapping food and transferring it towards the oral cavity. Appendage VII, which is probably uniramous, is posteroventrally directed and flap like. Each tergite of the thorax and posterior tagma covers at least a pair (probably two pairs) of probably biramous appendages with each ramus flap like and setose.

Radical hysterectomy: does the type of incision matter?

OBJECTIVE: Our purpose was to evaluate and compare aspects of operative accessibility and perioperative outcome after radical hysterectomy and pelvic lymphadenectomy performed through a vertical, Pfannenstiel, or Maylard abdominal incision. STUDY DESIGN: During an 8-year interval, 236 patients underwent radical hysterectomy and pelvic lymphadenectomy as primary treatment for cervical cancer at the Watson Clinic. Patients were admitted under a standard perioperative protocol, and all procedures were performed by a gynecologic oncologist. All clinical data was recorded prospectively and updated regularly. RESULTS: Radical hysterectomy and pelvic lymphadenectomy was completed through a vertical (n = 113), Pfannenstiel (n = 78), or Maylard (n = 45) incision. Although lesion size and depth of stromal invasion was not different between incision types, patients with a Pfannenstiel incision were younger (p < 0.001) and weighed less than those with a vertical (p = 0.001) or Maylard (p < 0.025) incision. The Pfannenstiel was associated with a shorter operative time (Pfannenstiel vs Maylard, p < 0.05; Pfannenstiel vs vertical, p < 0.001), less blood loss (Pfannenstiel vs Maylard, p < 0.025; Pfannenstiel vs vertical, p < 0.001), a lower risk of transfusion, and a shorter hospital stay (Pfannenstiel vs Maylard, p < 0.025; Pfannenstiel vs vertical, p < 0.001). These differences persisted when controlled for patient weight and surgical experience. There was no significant difference in the total number of nodes evaluated. No patient had a positive vaginal margin. CONCLUSION: Radical hysterectomy and pelvic lymphadenectomy can be safely performed through a vertical, Maylard, or Pfannenstiel incision. In a selected population a Pfannenstiel incision offers the potential benefit of less abdominal wall trauma without compromising surgical exposure or increasing the risk of surgical complications.