Heat Activation of Bacillus Anthracis Persists Over a Seven Day Period

Bacteria of the Bacillus genera are capable of forming dormant and resilient cells called spores in response to starvation. Spores can break dormancy in the presence of nutrients in a process called germination. Historically, spores are exposed to sublethal heat treatments to increase the extent and rate of germination. This process is known as heat activation (HA). Previous studies on Bacillus species indicate the effects of HA are reversible after 72 hours. After this time period, the spores must be reactivated. However, spores of Bacillus anthracis, a member of the Bacillus family, have not been tested to see how long they remain activated. In this study, B. anthracis spores were heat activated and germination was measured for seven days to see if they remained activated. B. anthracis spores were prepared by the exhaustion method in Difco Sporulation Media and extensively water washed. Each sporulation was split into three samples: no heat treatment (UH), heat activated on day one of the experiment (HA), and activation on the particular day relative to day one (Hn). Germination was initiated with 1mM L-alanine and 1mM inosine and was measured by the loss of optical density (OD) at 580nm. The assays were performed on days one, three, five, and seven. As expected, heat activation had a positive impact on spore germination. On day one, HA and H1 spores had a final OD loss of 57.24% and 57.88%, respectively, while the UH spores had an OD loss of 34.69%. On day seven, HA spores had an OD loss of 54.16%, H7 had a 52.66% OD loss, and UH had a 27.49% OD loss. Although all reactions showed a decrease in germination on day seven compared to day one, a two- way ANOVA test showed this decrease to be statistically insignificant. The heated samples (HA, Hn) were shown to be significantly different from the UH sample on both day one and day seven. Interestingly, there was no significant difference in germination for HA spores between day one and day seven, suggesting that HA spores can remain activated over seven days. No significant difference was seen between HA and Hn for either day. This study shows that HA impacts B. anthracis spores for seven days, much longer than originally expected. This changes our understanding of heat activation in B. anthracis. Further studies will help define the time it takes for spores to be inactivated as well as test the effects of storage conditions on activation

The Hardy Space of a Slit Domain

If H is a Hilbert space and T : H ? H is a continous linear operator, a natural question to ask is: What are the closed subspaces M of H for which T M ? M? Of course the famous invariant subspace problem asks whether or not T has any non-trivial invariant subspaces. This monograph is part of a long line of study of the invariant subspaces of the operator T = M (multiplication by the independent variable z, i. e. , M f = zf ) on a z z Hilbert space of analytic functions on a bounded domain G in C. The characterization of these M -invariant subspaces is particularly interesting since it entails both the properties z of the functions inside the domain G, their zero sets for example, as well as the behavior of the functions near the boundary of G. The operator M is not only interesting in its z own right but often serves as a model operator for certain classes of linear operators. By this we mean that given an operator T on H with certain properties (certain subnormal operators or two-isometric operators with the right spectral properties, etc.), there is a Hilbert space of analytic functions on a domain G for which T is unitarity equivalent to M.https://scholarship.richmond.edu/bookshelf/1095/thumbnail.jp

Utilizing Community-Based Social Marketing in a Recycling Intervention With Tailgaters

The purpose of the current study was to design and implement a pilot intervention following the community-based social marketing (CBSM) process (McKenzie-Mohr & Smith, 1999) and Darnton’s (2008) social marketing framework to change the recycling knowledge and behaviors of tailgaters during home football events for a particular institution of higher education. Researchers asked what effect does a CBSM intervention have on the recycling behavior (via self-reported opinion and actual materials recycled) as well as self-reported knowledge among tailgaters during home football events for a particular IHE. In addition, researchers asked whether the use of students and student-athletes, from the respective IHE, as recycling educators would be better received by tailgaters than some other set of individuals. Both objective and subjective evidence support a conclusion that the pilot intervention enhanced the recycling behavior and recycling knowledge of tailgaters. Subjective evidence supports a conclusion that the tailgaters were more receptive to students and student-athletes than they would have been had some other set of individuals been the recycling educators. This study contributes to the body of knowledge by demonstrating that community-based social marketing approaches to behavior change, particularly multifaceted approaches incorporating a variety of techniques, are effective in positively changing behavior in a sport tailgating setting. Furthermore, this study provides insights for managers that tailgaters, in a context rife with identifiable constraints, are receptive to educational and behavior change-based interventions and participating in a research study utilizing the methodologies outlined in the current study. The CBSM approach described herein may serve as an effective manner in which to approach these behavior-change initiatives, green or otherwise. The present study provides an example of how sport organizations, and college athletics in particular, can operate to address proenvironmental efforts specific to mitigating the burden that sport places on the physical environment

Ternatin and improved synthetic variants kill cancer cells by targeting the elongation factor-1A ternary complex.

Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1A·GTP·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products

Investigation of Truncated Waveguides

The design, fabrication, and performance of truncated circular and square waveguide cross-sections are presented. An emphasis is placed upon numerical and experimental validation of simple analytical formulae that describe the propagation properties of these structures. A test component, a 90-degree phase shifter, was fabricated and tested at 30 GHz. The concepts explored can be directly applied in the design, synthesis and optimization of components in the microwave to sub-millimeter wavebands

The Development of Swimming Skills for African American Youth: Parent and Caregiver Perceptions of Barriers and Motivations

African American urban youth participate in swimming at an alarmingly low rate with 69% self-reporting low or no swimming skill (Irwin, Irwin, Martin,&Ross, 2010). This lack of participation translates into a drowning rate three times as high as than their White/European American peers (CDC, 2009). To investigate this issue, 12 focus groups were conducted with parents and caregivers of swimming and nonswimming children at YMCAs in six American cities. Parents/caregivers who self-identified as Black or African American shared attitudes and values that impacted their child\u27s swimming participation. Some participants in the study identified structural barriers such as a lack of time, money, or facilities. Others shared attitudes of fear and discomfort in being in and around water. Parent/caregiver attitudes had a substantial impact on children\u27s opportunities to learn to swim. There was evidence that cultural expectations about swimming impacted the choices parents in this study made regarding swimming participation. Focus group participants shared strategies of effective messaging to influence caregiver attitudes to positively impact participation. © 2014 Human Kinetics, Inc

Electron multiplication CCD detector technology advancement for the WFIRST-AFTA coronagraph

The WFIRST-AFTA (Wide Field InfraRed Survey Telescope-Astrophysics Focused Telescope Asset) is a NASA space observatory. It will host two major astronomical instruments: a wide-field imager (WFI) to search for dark energy and carry out wide field near infrared (NIR) surveys, and a coronagraph instrument (CGI) to image and spectrally characterize extrasolar planets. In this paper, we discuss the work that has been carried out at JPL in advancing Electron Multiplying CCD (EMCCD) technology to higher flight maturity, with the goal of reaching a NASA technology readiness level of 6 (TRL-6) by early-to-mid 2016. The EMCCD has been baselined for both the coronagraph's imager and integral field spectrograph (IFS) based on its sub-electron noise performance at extremely low flux levels - the regime where the AFTA CGI will operate. We present results from a study that fully characterizes the beginning of life performance of the EMCCD. We also discuss, and present initial results from, a recent radiation test campaign that was designed and carried out to mimic the conditions of the WFIRST-AFTA space environment in an L2 orbit, where we sought to assess the sensor's end of life performance, particularly degradation of its charge transfer efficiency, in addition to other parameters such as dark current, electron multiplication gain, clock induced charge and read noise

A Tripodal Ruthenium(II) Polypyridyl Complex with pH Controlled Emissive Quenching

A tripodal podand has been prepared and complexed to ruthenium(II) creating a metal complex with C3-symmetry and an enclosed cavity. The complex shows the anticipated enhanced emission when compared to [Ru(bipy)3]2+ in acetonitrile. The emission from this cryptand like structure is invariant to the introduction of monovalent cations in aqueous solution, but a significant drop in the emission was observed with increasing pH over a very broad pH range (3 to 12). This is attributed to an N to t2g electron transfer in the excited-state in the unprotonated form with a transfer rate of the order of 4.2 x 105 s-1. The crystal structure indicates the inclusion of water within the cavity suggesting that the protonation of a tertiary amine can be effectively moderated by a water molecule held in close proximity within a rigid cavit

Non-Fasting High-Density Lipoprotein Is Associated With White Matter Microstructure in Healthy Older Adults

A growing body of evidence indicates that biomarkers of cardiovascular risk may be related to cerebral health. However, little is known about the role that non-fasting lipoproteins play in assessing age-related declines in a cerebral biomarker sensitive to vascular compromise, white matter (WM) microstructure. High-density lipoprotein cholesterol (HDL-C) is atheroprotective and low-density lipoprotein cholesterol (LDL-C) is a major atherogenic lipoprotein. This study explored the relationships between non-fasting levels of cholesterol and WM microstructure in healthy older adults. A voxelwise and region of interest approach was used to determine the relationship between cholesterol and fractional anisotropy (FA). Participants included 87 older adults between the ages of 59 and 77 (mean age = 65.5 years, SD = 3.9). Results indicated that higher HDL-C was associated with higher FA in diffuse regions of the brain when controlling for age, sex, and body mass index (BMI). HDL-C was also positively associated with FA in the corpus callosum and fornix. No relationship was observed between LDL-C and FA. Findings suggest that a modifiable lifestyle variable associated with cardiovascular health may help to preserve cerebral WM

Inorganic nitrate, hypoxia, and the regulation of cardiac mitochondrial respiration-probing the role of PPARα.

Dietary inorganic nitrate prevents aspects of cardiac mitochondrial dysfunction induced by hypoxia, although the mechanism is not completely understood. In both heart and skeletal muscle, nitrate increases fatty acid oxidation capacity, and in the latter case, this involves up-regulation of peroxisome proliferator-activated receptor (PPAR)α expression. Here, we investigated whether dietary nitrate modifies mitochondrial function in the hypoxic heart in a PPARα-dependent manner. Wild-type (WT) mice and mice without PPARα (Ppara-/-) were given water containing 0.7 mM NaCl (control) or 0.7 mM NaNO3 for 35 d. After 7 d, mice were exposed to normoxia or hypoxia (10% O2) for the remainder of the study. Mitochondrial respiratory function and metabolism were assessed in saponin-permeabilized cardiac muscle fibers. Environmental hypoxia suppressed mass-specific mitochondrial respiration and additionally lowered the proportion of respiration supported by fatty acid oxidation by 18% (P < 0.001). This switch away from fatty acid oxidation was reversed by nitrate treatment in hypoxic WT but not Ppara-/- mice, indicating a PPARα-dependent effect. Hypoxia increased hexokinase activity by 33% in all mice, whereas lactate dehydrogenase activity increased by 71% in hypoxic WT but not Ppara-/- mice. Our findings indicate that PPARα plays a key role in mediating cardiac metabolic remodeling in response to both hypoxia and dietary nitrate supplementation.-Horscroft, J. A., O'Brien, K. A., Clark, A. D., Lindsay, R. T., Steel, A. S., Procter, N. E. K., Devaux, J., Frenneaux, M., Harridge, S. D. R., Murray, A. J. Inorganic nitrate, hypoxia, and the regulation of cardiac mitochondrial respiration-probing the role of PPARα