Sternoclavicular Bacterial Arthritis

Bacterial infection of the sternoclavicular joint is an unusual event, with cases being reported in those with diabetes mellitus, in intravenous drug abusers, and in patients afflicted with rheumatoid arthritis. A case of this unique infection occurred in a person not known to be at risk for septic arthritis. Our report shows the difficulty in diagnosing this disorder.     

Fossil bananas (Musaceae): Ensete oregonense sp. nov. from the Eocene of western North America and its phytogeographic significance

Fossil seeds of Ensete, a genus presently native to Asia and Africa, have been recovered from the middle Eocene of Oregon, confirming the presence of Musaceae in the North American Tertiary. The seed of Ensete oregonense sp. nov. is operculate, with a well-defined micropylar collar, a pronounced chalazal chamber, and a wide hilar cavity. A survey of seed morphology in extant Zingiberales provides characters for distinguishing Musaceae from other families of the order, furnishes criteria for distinguishing the three extant genera of Musaceae (Musa, Ensete and Musella), and facilitates critical assessment of fossil seed remains. “Musa” cardiosperma Jain from the Cretaceous/Tertiary boundary Deccan Series of India is excluded from Musaceae (although retained in Zingiberales) on the basis of fruit and seed characters, including the lack of laticifers and absence of a chalazal chamber. We reexamined the musaceous seeds from Colombia that previously were described as Tertiary fossils (Musa enseteformis Berry, 1925) and now believe that they are recent, nonfossil remains, evidently from Ensete ventricosum, which is grown in the region where the specimens were originally obtained. In addition, a reputed fossil banana fruit from the Cretaceous of Colombia was reexamined and determined to be a concretion of nonbiological origin. Ensete oregonense is significant therefore, as the first unequivocal fossil record of Ensete and of Musaceae. Although the Musaceae are currently native only to the Old World tropics, this discovery establishes that the family was present in North America about 43 million years ago.     

Relationships between irradiance and photosynthesis for marine benthic green algae (Chlorophyta) of differing morphologies

Photosynthesis-irradiance relationships were determined in the field for five species of littoral and shallow sublittoral marine benthic green algae (Chlorophyta) of differing morphologies. Each species exhibited a linear increase in photosynthetic rate with increasing irradiance up to a maximum light-saturated value. Full sunlight (1405 to 1956 μE·m^?2·s^?1) inhibited photosynthesis of all species except the thick, optically dense, Codium fragile (Sur.) Har. Compensation irradiances ranged from 6.1 μE·m^?2·s^?1 for Enteromorpha intestinalis (L.) Link to 11.4 μE·m^?2·s^?1 for Ulva lobata (Kütz) S. & G. and did not reveal a consistent relationship to seaweed morphology. Saturation irradiances were determined statistically (I_k) and visually from graphical plots. with the latter technique resulting in values three to eight times higher and different comparative rankings of species than the former. I_k saturation irradiances were highest for Chaetomorpha linum (Müll.) Kütz. (81.9 μE·m^?2·s^?1) and lowest for Codium fragile (49.6 μE·m^?2·s^?1) and did not reveal a relationship with seaweed morphology. Regression equations describing light-limited photosynthetic rates and the relative magnitudes of the maximal net photosynthetic responses both strongly suggested a relationship with seaweed morphology. Highest net photosynthetic rates were obtained for the thin, sheet-like algae Ulva lobata (9.2 mg C·g dry wt^?1·h^?1), U. rigida C. Ag. (6.5 mg C·g dry wt^?1·h^?1) and the tubular form, Enteromorpha intestinalis (7.3 mg C·g dry wt^?1·h^?1), while lowest rates occurred for Codium fragile (0.9 mg C·g dry wt^?1·h^?1). Similarly, steepest light-limited slopes were found for the algae of simpler morphology, while the most gradual slope was determined for Codium fragile, the alga with greatest thallus complexity.     

Stromatolitic digitate sinters form under wide‐ranging physicochemical conditions with diverse hot spring microbial communities

Digitate siliceous hot spring deposits are a form of biomediated sinter that is relatively common in the Taupo Volcanic Zone (TVZ), New Zealand, and elsewhere on Earth. Such deposits have gained prominence recently because of their morphological similarity to opaline silica rocks of likely hot spring origin found by the Spirit rover on Mars and the consequent implications for potential biosignatures there. Here, we investigate the possible relationship between microbial community composition and morphological diversity among digitate structures from actively forming siliceous hot spring sinters depositing subaerially in shallow discharge channels and around pool rims at several physicochemically distinct geothermal fields in the TVZ. The TVZ digitate sinters range in morphologic subtype from knobby to spicular, and are shown to be microstromatolites that grow under varied pH ranges, temperatures, and water chemistries. Scanning electron microscopy and molecular analyses revealed that TVZ digitate sinters are intimately associated with a diverse array of bacterial, archaeal and eukaryotic micro‐organisms, and for most digitate structures the diversity and quantity of prokaryotes was higher than that of eukaryotes. However, microbial community composition was not correlated with morphologic subtypes of digitate sinter, and observations provided limited evidence that pH (acidic versus alkali) affects morphology. Instead, results suggest hydrodynamics may be an important factor influencing variations in morphology, while water chemistry, pH, and temperature are strong drivers of microbial composition and diversity.