The Distribution and Paleoecological Interpretation of Cornulites in the Waynesville Formation (Upper Ordovician) of Southwestern Ohio

Author Institution: Department of Geology, Wittenberg University, Springfield, Ohio and Department of Earth and Planetary Sciences, University of Pittsburgh, Pittsburgh, PennsylvaniaSeventeen species of marine invertebrates collected from the Upper Ordovician Waynesville Formation of southwestern Ohio were found encrusted by Cornulites, a presumed tubicolous annelid worm. Encrustation was interpreted as symbiotic in cases where the cornulitid tubes exhibited preferred orientation upon the exoskeleton of the host. This situation may reflect cornulitid utilization of feeding currents generated or employed by the host species. Symbiotic attachments of Cornulites were encountered most commonly on several species of brachiopods, but were also observed on a pelecypod, a monoplacophoran, two species of bryozoa, and questionably on a gastropod and nautiloid. Post-mortem encrustation of a host by Cornulites was inferred either from random orientation of the cornulitid tubes or from attachment in a manner or position incompatible with the functional morphology of the host species. Cornulites was found in post-mortem association with brachiopods, bryozoans, and a trilobite. In this situation the host species presumably provided, after death, a suitably hard substrate for cornulitid larval attachment. Symmetrically positioned cornulitid clusters on a specimen of Cyrtolites sp. cf. C. ornatus Conrad supports the accepted, but unproven, interpretation of bilaterally developed mantle-cavity organs in cyclomyan monoplacophorans

Impact flash for micrometeoroid detection Final report

Impact flash used for detection and analysis of micrometeoroid

Identifying Extension Information Delivery Methods For Environmental Issues

The primary purpose of this study was to identify the types of information sources that farmers find useful, and the human resource organizations they depend upon when confronted with environmental issues

Letter from Susan B. Rollins, Great Falls, New Hampshire, to Anne Whitney, 1884 October 24

https://repository.wellesley.edu/whitney_correspondence/2850/thumbnail.jp

Initial Effects of Prescribed Burning on Survival and Nesting Success of Northern Bobwhites in West-Central Texas

Fire is often prescribed for managing habitat for northern bobwhites (Colinus virginianus) in the southeastern United States, yet little is known about its use as a tool in more xeric portions of the species’ range. This study was conducted from 1994 to 1995 on 3 sites in the northern Edwards Plateau ecoregion of Texas to monitor immediate post-burn effects on bobwhite ecology. Each site included a burned pasture paired with an unburned control. We radiomarked \u3e= 50 bobwhites (25/pasture) at each study site with neck-loop transmitters just prior to burning and monitored their survival and nesting habits for 6 months post-burn. Survival was similar (P \u3e 0.05) between burned and unburned areas. Predation was the leading cause of mortality, with mammals and raptors accounting for 68% and 31% of the predation, respectively. Nest initiation and success were low for both treatments. Nest sites occurred mostly in association with prickly pear cactus (Opuntia spp.). Our results suggest that relatively ‘‘cool’’ prescribed burns had few short-term effects on bobwhite survival in west-central Texas. However, reductions in cacti density and cover that often occur post-burn, especially if followed by an application of herbicide (i.e., picloram), may reduce the number of potential nesting sites for bobwhites

Steady Hall Magnetohydrodynamics Near a X-type Magnetic Neutral Line

Hall magnetohydrodynamics (MHD) properties near a two-dimensional (2D) X-type magnetic neutral line in the steady state are considered via heuristic and rigorous developments. Upon considering the steady-state as the asymptotic limit of the corresponding \textit{time-dependent} problem and using a rigorous development, Hall effects are shown to be able to sustain the hyperbolicity of the magnetic field (and hence a more open X-point configuration) near the neutral line in the steady state. The heuristic development misses this subtle connection of the steady state with the corresponding \textit{time-dependent} problem and predicts only an elongated current-sheet configuration (as in resistive MHD). However, the heuristic development turns out to be useful in providing insight into the lack of dependence of the reconnection rate on the mechanism breaking the frozen-in condition of the magnetic field lines. The latter result can be understood in terms of the ability of the ions and electrons to transport equal amounts of magnetic flux per unit time out of the reconnection region.Comment: 1-10 page

FR900482, a close cousin of mitomycin C that exploits mitosene-based DNA cross-linking

AbstractBackground: The class of antitumor antibiotics that includes FR900482 has a very close structural analogy to the mitomycins, one of which, mitomycin C, has been in widespread clinical use for more than 20 years. Like mitomycin C, these antitumor antibiotics are reductively activated in vivo and covalently cross-link DNA as a result of activity of the mitosene moiety generated on reduction. Owing to differences in structure and the attendant mechanistic differences in bioreductive activation between the mitomycins and FR900482, FR900482 does not produce an adventitious superoxide radical anion during reductive activation and thus does not exhibit oxidative strand scission of DNA. It is postulated that the low clinical toxicity of FR900482 relative to mitomycin C is a direct manifestation of the mechanistic differences of bioreductive activation leading to the highly reactive DNA cross-linking mitosenes.Results: Using Fe(II)-EDTA footprinting, we showed that the two natural products FR900482 (1) and dihydro, FR66979 (3), and the semi-synthetically derived triacetate FK973 (2), display remarkable selectivity for 5′ deoxy-CG sequences of DNA, and that this selectivity is abolished upon deletion of the exocyclic N2 amine of either participating guanosine residue. In addition, we investigated the mono alkylation abilities of FR66979 with respect to a number of inosine-substituted oligonuclectides and observed that the FR900482 class of compounds were able to give rise to easily separable orientation isomers of their respective cross-links.Conclusions: The FR900482 class of antitumor antibiotics cross-link DNA in a fashion analogous to the mitomycins. The cross-linking reaction yields two orientation, isomers which are of vastly different electrophoretic mobility and which also exhibit radically different DNA-protein recognition properties upon reaction with Alul restriction endonuclease. In addition, mono-alkylation of DNA by FR66979 shows little, if any, dependence upon pre-covalent interactions deemed necessary for the mitomycins. These insights support the proposal that the FR900482 class of compounds represents a compelling clinical replacement for mitomycin C, given its greatly reduced host toxicity and superior DNA interstrand cross-linking efficacy

Validating gravitational-wave detections: The Advanced LIGO hardware injection system

Hardware injections are simulated gravitational-wave signals added to the Laser Interferometer Gravitational-wave Observatory (LIGO). The detectors’ test masses are physically displaced by an actuator in order to simulate the effects of a gravitational wave. The simulated signal initiates a control-system response which mimics that of a true gravitational wave. This provides an end-to-end test of LIGO’s ability to observe gravitational waves. The gravitational-wave analyses used to detect and characterize signals are exercised with hardware injections. By looking for discrepancies between the injected and recovered signals, we are able to characterize the performance of analyses and the coupling of instrumental subsystems to the detectors’ output channels. This paper describes the hardware injection system and the recovery of injected signals representing binary black hole mergers, a stochastic gravitational wave background, spinning neutron stars, and sine-Gaussians

Advantages of the no-scalpel vasectomy technique

The no-scalpel vasectomy (NSV) technique should be used instead of the standard incisional method. (Strength of Recommendation: A, based on systematic reviews, mixed-quality randomized controlled trials [RCTs], cohort studies, and case-control series.) The NSV technique is associated with fewer complications, produces less perioperative and postoperative pain, results in quicker recovery, takes less time to perform, and is as effective as standard incisional vasectomy