Confocal analysis of nervous system architecture in direct-developing juveniles of Neanthes arenaceodentata (Annelida, Nereididae)

Background: Members of Family Nereididae have complex neural morphology exemplary of errant polychaetes and are leading research models in the investigation of annelid nervous systems. However, few studies focus on the development of their nervous system morphology. Such data are particularly relevant today, as nereidids are the subjects of a growing body of "evo-devo" work concerning bilaterian nervous systems, and detailed knowledge of their developing neuroanatomy facilitates the interpretation of gene expression analyses. In addition, new data are needed to resolve discrepancies between classic studies of nereidid neuroanatomy. We present a neuroanatomical overview based on acetylated α-tubulin labeling and confocal microscopy for post-embryonic stages of Neanthes arenaceodentata, a direct-developing nereidid. Results: At hatching (2-3 chaetigers), the nervous system has developed much of the complexity of the adult (large brain, circumesophageal connectives, nerve cords, segmental nerves), and the stomatogastric nervous system is partially formed. By the 5-chaetiger stage, the cephalic appendages and anal cirri are well innervated and have clear connections to the central nervous system. Within one week of hatching (9-chaetigers), cephalic sensory structures (e.g., nuchal organs, Langdon's organs) and brain substructures (e.g., corpora pedunculata, stomatogastric ganglia) are clearly differentiated. Additionally, the segmental-nerve architecture (including interconnections) matches descriptions of other, adult nereidids, and the pharynx has developed longitudinal nerves, nerve rings, and ganglia. All central roots of the stomatogastric nervous system are distinguishable in 12-chaetiger juveniles. Evidence was also found for two previously undescribed peripheral nerve interconnections and aspects of parapodial muscle innervation. Conclusions: N. arenaceodentata has apparently lost all essential trochophore characteristics typical of nereidids. Relative to the polychaete Capitella, brain separation from a distinct epidermis occurs later in N. arenaceodentata, indicating different mechanisms of prostomial development. Our observations of parapodial innervation and the absence of lateral nerves in N. arenaceodentata are similar to a 19th century study of Alitta virens (formerly Nereis/Neanthes virens) but contrast with a more recent study that describes a single parapodial nerve pattern and lateral nerve presence in A. virens and two other genera. The latter study apparently does not account for among-nereidid variation in these major neural features

Preliminary Report on a Stratified Late Archaic-Woodland Era Rockshelter in Rogers County, Oklahoma

In northeastern Oklahoma, very little is known about the transition from the Late Archaic to the Woodland period (Wyckoff and Brooks, 1983: 55). To date, most of the archeological evidence documenting this time period has been derived from sites with mixed or otherwise uncertain components. In this report, we present a preliminary description of a small rockshelter, 34RO252, which has a Late Archaic deposit stratigraphically below a Woodland era cultural deposit. These two deposits are unmixed, discrete, and are physically separated by an apparently sterile clay soil horizon. It is anticipated that the stratified cultural deposits at this site will help characterize the transition from the Late Archaic to the Early Woodland period along the Verdigris River in northeast Oklahoma. This site was first reported in April 1994 by two men who had discovered partially exposed human skeletal remains located in the rear remnant of a rockshelter at Oologah Lake in Rogers County, Oklahoma. The two men illegally excavated the remains and removed them from the site. 1 The rockshelter where the remains originated was subsequently examined by the authors and additional skeletal material was identified, in situ, in an exposed soil profile. A series of three radiocarbon assays, described below, placed the cultural deposit and the human remains within the Late Archaic-Woodland period (circa 780 B.C. to A.O. 900).2 This site is provisionally classified as corresponding to a cultural sequence that includes the old Grove C described by Purrington and Vehik

Chronometrics at the Norman Site

Unfortunately, some of the most significant sites in eastern Oklahoma have been those with the least published information. This is a well-known consequence of the pre-World War II social aid-sponsored excavations that produced large fieldwork projects, but very little in the way of laboratory work or publication. The Norman site, in Wagoner County of eastern Oklahoma, is a major mound center that falls into this category. This report presents a specific orientation to the further analysis of the site, documentation of the available radiocarbon dates, and a few interpretive comments on regional chronology. Although the authors have an interest in producing a full-scale study of the site, we determined that for now it is beneficial to present some of the key information as it becomes available, such as the radiocarbon dates

Dining in: intracellular bacterial pathogen interplay with autophagy

Intracellular bacterial pathogens have evolved many ways to manipulate host cells for successful infection. Many of these pathogens use specialized secretion systems to inject bacterial proteins into the host cytosol that manipulate cellular processes to favor infection. Autophagy is a eukaryotic cellular remodeling process with a critical role in many diseases, including bacterial clearance. A growing field of research highlights mechanisms used by intracellular bacteria to manipulate autophagy as a pro-survival strategy. This review focuses on a select group of bacterial pathogens with diverse intracellular lifestyles that exploit autophagy-derived nutrients and membrane for survival. This group of pathogens uses secretion systems and specific effectors to subvert distinct components of autophagy. By understanding how intracellular pathogens manipulate autophagy, we gain insight not only into bacterial pathogenesis but also host cell signaling and autophagolysosome maturation

Simultaneous detection of Legionella species and L. anisa, L. bozemanii, L. longbeachae and L. micdadei using conserved primers and multiple probes in a multiplex real-time PCR assay

AbstractLegionnaires' disease is a severe respiratory disease that is estimated to cause between 8,000 and 18,000 hospitalizations each year, though the exact burden is unknown due to under-utilization of diagnostic testing. Although Legionella pneumophila is the most common species detected in clinical cases (80-90%), other species have also been reported to cause disease. However, little is known about Legionnaires' disease caused by these non-pneumophila species. We designed a multiplex real-time PCR assay for detection of all Legionella spp. and simultaneous specific identification of four clinically-relevant Legionella species, L. anisa, L. bozemanii, L. longbeachae, and L. micdadei, using 5′-hydrolysis probe real-time PCR. The analytical sensitivity for detection of nucleic acid from each target species was ≤50fg per reaction. We demonstrated the utility of this assay in spiked human sputum specimens. This assay could serve as a tool for understanding the scope and impact of non-pneumophila Legionella species in human disease

A brief introduction to nomography: graphical representation of mathematical relationships

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Nomographs (or nomograms, or alignment charts) are graphical representations of mathematical relationships (extending to empirical relationships of data) which are used by simply applying a straightedge across the plot through points on scales representing independent variables, which then crosses the corresponding datum point for the dependent variable; the choice among independent and dependent variable is arbitrary so that each variable may be determined in terms of the others. Examples of nomographs in common current use compute the lift available for a hot-air balloon, the boiling points of solvents under reduced pressure in the chemistry laboratory, and the relative forces in a centrifuge in a biochemical laboratory. Sundials represent another ancient yet widely familiar example. With the advent and ready accessibility of the computer, printed mathematical tables, slide rules and nomographs became generally redundant. However, nomographs provide insight into mathematical relationships, are useful for rapid and repeated application, even in the absence of calculational facilities, and can reliably be used in the field. Many nomographs for various purposes may be found online. This paper describes the origins and development of nomographs, illustrating their use with some relevant examples. A supplementary interactive Excel file demonstrates their application for some simple mathematical operations

District-led School Turnaround: Aiming for Ambitious and Equitable Instruction in Shelby County’s iZone

The Shelby County iZone is a district-led effort to dramatically improve, or “turn around,” 23 of the lowest performing schools in Tennessee in the 15th largest district in the country. Despite circumstances that have derailed many past reforms, iZone schools have made statistically significant and educationally meaningful gains in mathematics and English language arts (ELA) (Zimmer, Henry, Kho, & Viano, 2015). This report presents the findings of a multi-year research project that examined the evolution of the iZone as it shifted its strategy from school-level autonomy to one that featured a common curriculum, shared pedagogy, and collegial learning. The analysis delves into the challenges that iZone leaders, principals, and teachers confronted in coping with the needs of a student population mired in intergeneration poverty, rigorous performance standards, and a stringent accountability system. The results illuminate the importance of multi-level system re-design, continuous improvement, and compromise and negotiation among key stakeholder groups

Influence of bed patchiness, slope, grain hiding, and form drag on gravel mobilization in very steep streams

Steep streams are a major portion of channel networks and provide a link to transport sediment from hillslopes to lower gradient rivers. Despite their importance, key unknowns remain, perhaps foremost of which is evaluating in steep streams empirical laws for fluvial sediment transport developed for low-gradient rivers. To address this knowledge gap, we painted sediment in situ over 3 years to monitor incipient sediment motion and sediment-patch development in five small (drainage areas of 0.04–2 km^2) and steep (slopes of 5–37%) tributaries of Elder Creek, California, United States. We found that channel beds organized into size-sorted sediment patches which displayed active fluvial transport of gravel annually, consistent year-to-year patch median grain sizes, partial transport of bed material, and significantly higher values of critical Shields stress for incipient sediment motion compared to that observed for lower gradient rivers. The high critical Shields stresses (up to ≈0.5 for the median grain size) agree within a factor of ~3 to theoretical predictions which account for slope-dependent hydraulics, grain hiding, and sediment patches. For grains of approximately the same size as the roughness length scale, slope-dependent hydraulics and bed patchiness are the dominant controls on critical Shields stress values, while grain hiding is important for grains larger or smaller than the roughness length scale. Form drag exists in our monitored tributaries but has a smaller influence than the above effects. Our field observations show fluvial processes contribute to sediment mobilization in steep channels which are often considered to be dominated by debris flows

Composition for personal growth : program design and evaluation.

<p>Two categories were used for cross-validation of the model, either type 1 or type 2. Clinical isolates were treated as an unknown class and cross-validated sensitivity, specificity, and class error were based on their classification prediction score with their respective reference strain control class. CV, cross-validated.</p><p>Cross-validated PLS-DA modeling statistics for the prediction performance for NA-SERS typing of individual type 1 and 2 <i>M</i>. <i>pneumoniae</i> clinical isolates.</p