The stationary phase expression of many conserved, adaptive bacterial proteins is dependent on RpoS, a second vegetative sigma factor. The regulation of RpoS itself, however, is complex and not fully ...understood, particularly at the level of transcription. In this report, we show that the observed hydrogen peroxide sensitivity of a mutant defective in expression of barA, a bacterial virulence factor, can be explained by a reduction in catalase activity, an RpoS‐controlled function. Levels of katE mRNA, encoding the major catalase of Escherichia coli, were much lower in the barA mutant, suggesting that BarA is required for the expression of this RpoS‐regulated gene. Expression of another RpoS‐regulated gene, osmY, was also found to be severely reduced in the barA mutant. Employing Western analyses with anti‐RpoS antisera and Northern analyses using probes specific for rpoS, we found that BarA is required for the exponential phase induction of RpoS itself. Operon lacZ fusion expression studies and Northern analyses indicate that BarA itself is maximally expressed in early exponential phase cultures immediately preceding the transcriptional induction of RpoS. Results of primer extension studies indicate that exponential phase expression from the rpoSp1 promoter is reduced by more than 85% in a barA mutant but could be efficiently complemented by a plasmid‐borne copy of barA in trans. These results suggest that regulatory signals that are operant in exponentially growing cultures play an important role in effecting stationary phase gene expression.
Abstract
A mammalian petrosal from the Lower Cretaceous Teete locality in Yakutia (Russia) shows a prominent and complex system of venous channels in the bony wall of the pars cochlearis surrounding ...the straight cochlear canal. This complex venous system is distinctive and more strongly developed than in other mammalian petrosals. A bony ridge is present on the ventral side of the cochlear canal endocast, continuing from between fenestra vestibuli and fenestra cochleae in anterior direction. This ridge corresponds to the position of the scala tympani, and is similar to the secondary bony lamina of crown therians, but lacks the sharp laminar edge. The fenestra cochleae is separate from the canal for the aquaeductus cochleae (derived), but the fenestra retains a deep sulcus that resembles the perilymphatic sulcus (plesiomorphic). The fenestra cochleae is oval shaped and deep. The straight cochlear canal with a ridge on the ventral side strongly resembles that of eutriconodontans like
Priacodon fruitaensis
from the Upper Jurassic of North America. However, thick and extensive venous channels in the pars cochlearis are otherwise known from docodontans. In the Teete petrosal the channels are even more developed, and resemble the pattern recently reported from possible haramiyidan petrosals from the Middle Jurassic of western Siberia (Russia). Both eutriconodontan and haramiyidan dental remains are known from the Teete locality beside that of tritylodontids and docodontans.
Due to the peculiar combination of dental features characteristic for different squaliform families, the position of the Late Cretaceous genera Protoxynotus and Paraphorosoides within Squaliformes ...has long been controversial. In this study, we revise these genera based on previously known fossil teeth and new dental material. The phylogenetic placement of Protoxynotus and Paraphorosoides among other extant and extinct squaliforms is discussed based on morphological characters combined with DNA sequence data of extant species. Our results suggest that Protoxynotus and Paraphorosoides should be included in the Somniosidae and that Paraphorosoides is a junior synonym of Protoxynotus. New dental material from the Campanian of Germany and the Maastrichtian of Austria enabled the description of a new species Protoxynotus mayrmelnhofi sp. nov. In addition, the evolution and origin of the characteristic squaliform tooth morphology are discussed, indicating that the elongated lower jaw teeth with erected cusp and distinct dignathic heterodonty of Protoxynotus represents a novel functional adaptation in its cutting-clutching type dentition among early squaliform sharks. Furthermore, the depositional environment of the tooth bearing horizons allows for an interpretation of the preferred habitat of this extinct dogfish shark, which exclusively occupied shelf environments of the Boreal- and northern Tethyan realms during the Late Cretaceous.
•First evidence of Protoxynotus in the Tethyan realm.•Synonymy of Paraphorosoides and Protoxynotus.•Protoxynotus is an early representative of the Somniosidae.•Novel functional adaptation of dentition among early squaliform sharks.
The German yellowjacket, Vespula germanica (F.) (Hymenoptera: Vespidae), was introduced into Australia in 1959 and has established throughout southern Australia. In urban environments, V. germanica ...is frequently a nuisance pest at public gatherings and to homeowners. In native environments, it has the potential to pose a threat to native invertebrates. The current practice for controlling the wasps is nest destruction with pesticide. However, locating the nest(s) is not always practical or possible. Meat baits impregnated with an insecticide that foraging wasps cut and carry back to the nest offer a means of suppressing wasps where the nest sites are unknown. The success of meat baits depends on the attractiveness and acceptance of the meat to the wasp and the mode of action of the insecticide. Our objective was to determine wasp preference and acceptance of five processed meats: canned chicken or fish and freeze-dried chicken, fish, or kangaroo. We found that more wasps visited and took freeze-dried kangaroo and canned chicken than the other baits. Canned and freeze-dried fish were similarly preferred, and freeze-dried chicken was the least attractive and accepted by foraging wasps. Our findings demonstrate that wasps prefer some processed meats and hence take more loads back to the nest. By combining a suitable insecticide with a meat bait preferred by wasps, the likelihood of effective suppression of nuisance wasp populations should be increased.
This paper describes fragmentary turtle material (isolated basisphenoid, shell bones, humerus and ilium) from the Lower Cretaceous (Berriasian–Barremian) Teete locality in Yakutia (Eastern Siberia, ...Russia). All the material is attributed to one taxon of basal turtles (Mesochelydia indet.), based on the morphology of the basisphenoid, shell bones and humerus, as well as microanatomy and histology of the shell bones and humerus. Canals and foramina of the basisphenoid of this taxon revealed by CT scanning show an unusual pattern, which allows various interpretations and suggests a higher diversity of carotid and/or vidian systems in basal turtles than hitherto believed. Mesochelydia indet. from Teete fills an Early Cretaceous gap in the record of Asian basal turtles and represents the northernmost Asian non-marine turtle occurrence of the Mesozoic. All in all, the record of Asian basal turtles appears to be wider geographically and more complete temporally than previously thought. The Asian basal turtles are represented by at least three phylogenetic lineages: primitive Testudinata in the Late Triassic, primitive Mesochelydia from the Early Jurassic to the Early Cretaceous and primitive Perichelydia from the Middle Jurassic to the Late Cretaceous. The presence of such a primitive (Jurassic level) turtle in Teete supports the hypothesis that the vast territory of Siberia was a refugium for Jurassic vertebrate faunal elements. Details of the external morphology and histology of the Teete turtle material as well as its high paleolatitude occurrence argue in favor of its aquatic lifestyle.
Abstract only
6531
Background: Annual mammography is recommended to screen residual breast tissue for new cancers and recurrent disease after treatment for early stage breast cancer. This study aimed ...to assess mammography rates over time in breast cancer survivors. Methods: We used administrative claims data from a large U.S. commercial insurance database, OptumLabs, to retrospectively identify privately- and Medicare Advantage-insured women with operable breast cancer who had residual breast tissue after definitive breast surgery between 2006 and 2015. We required coverage for at least 13 months following surgery. For each subsequent 13-month time period, we only included women without a loss of coverage, bilateral mastectomy, metastatic breast cancer diagnosis, or non-breast cancer diagnosis. We calculated the proportion of patients who had a mammogram during each 13-month period following breast surgery. We used multivariable logistic regression to test for factors associated with mammography in the first 13 months. Results: The cohort included 26,011 women followed for a median of 2.9 years (IQR 1.9-4.6) after surgery; 63.1% were less than 65 years of age, and 74.4% were white. In their first year of follow-up, 86% underwent mammography, but by year 7, this decreased to 73%. Fewer than 1% underwent MRI instead of mammography. In multivariable analysis, mammograms were less likely during the first year after surgery among women aged < 50 years (odds ratio OR, 0.7; 95% confidence interval CI, 0.6 to 0.8), African Americans (OR, 0.7; 95% CI, 0.7 to 0.8), patients who underwent mastectomy (OR, 0.7; 95% CI, 0.6 to 0.7), and patients residing in the Western part of the country (OR, 0.9; 95% CI, 0.7 to 0.9). Those with 1-2 comorbidities were more likely (OR, 1.1; 95% CI 1.1-1.2) than those with none to have a mammogram during that period. Mammography use did not differ significantly by year of diagnosis (2006-2015). Conclusions: Even in an insured cohort, a substantial proportion of breast cancer survivors do not undergo annual surveillance mammography. Mammography use falls as the time from the early stage breast cancer diagnosis increases. Understanding factors associated with lack of mammographic screening may help improve survivorship care.
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