Reviving the Legacy of World War I

Students research what Americans remember and have forgotten about the Great War

Tracking and Characterization of Moving Acoustic Sources Using an Infrasound Array at Volcán Santiaguito, Guatemala

Active volcanic processes produce large amounts of acoustic energy within the infrasound band (0-20 Hz). Infrasound-sensitive microphones are often installed in addition to other forms of volcano monitoring equipment to increase the ability to remotely detect volcanic activity. In this study, an array of microphones was deployed without any additional sensor types for 36 hours at Santiaguito, Guatemala, to test the detection capabilities of a standalone microphone array. Array processing was applied to the recorded data, through frequency-domain beamforming and calculating a Fisher statistic (F). A changing F-threshold value was applied to differentiate between desired detections, or signal, and acoustic energy not originating from desired sources, or noise. Through determination of signal backazimuth, and knowing the azimuthal ranges of expected events, detections were categorized into three potential sources: volcanic explosion, volcanic rock fall, or non-volcanic rock fall. After characterizing a signal as one of the three event types, determination of relative occurrence of each event type showed that volcanic rock falls were the most common event through the deployment. Progression of signal backazimuth through time indicated movement of rock fall events. Explosion events were demonstrated to be non-moving as expected. Calculation of a spectral median frequency for these events, and comparison to signal backazimuth validates results of previous studies, that rock fall infrasound is characterized by higher frequencies than explosions. This method was shown to be effective for remotely categorizing activity at a volcano during time periods of low wind

Social Work With Affluent and Low-income Families: Attribution Theory

A study to assess attribution theory and the work done by social workers with wealthy and poor families was performed using two vignettes identical in information suggesting abuse, with one described as a wealthy family and the other a family living in poverty. Attribution theory suggests that humans label and assume certain traits to be true of different persons based on their status in our society. A person with a wealthy status may be viewed by their social worker as less likely to be abusive to their children because of their status, while a person living in poverty would be assumed to be more likely because of their status. So, it was hypothesized that social workers reading the wealthy vignette would note less of a concern about the observed potentially abusive situation in comparison with the responses given to the social workers reading about the same situation occurring in a family living in poverty. The vignettes were randomly distributed to 29 students and 14 professional social workers. Who were then asked to respond to the statements about the children in the family and the types of action the social worker should take, based on the suggested physical abuse in the vignettes. Findings do not show a statistically significant difference between responses given by social workers with the wealthy vignettes and social workers with the poor vignettes. However, differences in the mean responses of the wealthy and poor vignettes showed that the social workers who responded to the poor vignettes may have felt more urgency to follow up on the observed behavior because of potential abuse. This may be because of daily stressors that are typical of a family living in poverty. Parents living lives in poverty experience daily stressors and the emotions that accompany them may result in abusive or neglectful behavior. Although this may be true of poverty it does not always predict abuse and so social workers need to be aware of the influence of attribution theory on their work

Pleasure in Virtue: The Possibility of Willful Virtuous Behavior

Virtuous behavior has often been construed as having three requisite elements: right action, done for the right reason, and also carried out with the “right feeling,” i.e. without the contrary inclination of Aristotle’s merely continent individual. Some have argued that even if the right motivating reason(s) for action might not be directly within our power to act on at will, there are a number of steps we can take in order to make ourselves more responsive to the appropriate reasons – thus giving us indirect control over which reasons we take to be compelling. However, I believe that such accounts emphasize the importance of right action done for the right reason at the expense of giving a complete account of right feeling – and are thus incomplete pictures of both virtuous behavior and the way in which it is, to a degree, within our control, rather than solely a matter of moral luck. In this paper, I elaborate on these views, arguing that if we can control our reasons-responsiveness, it follows that we can likewise influence our sensitivity to what we have reason to desire. If we can make ourselves responsive to the best reasons in support of what we ought to desire, then in doing the right action for the right reason we will presumably satisfy a desire of ours, and thus we will take pleasure in acting virtuously, without a contrary inclination to do otherwise. And, I think this is true regardless of the outcome of debates surrounding the nature of both motivation and desires. In this way, then, I argue that the necessary components for virtuous behavior – doing the right action, for the right reason, and especially with the right feeling – are truly “up to us” in large part, and not merely to chance

In C andida albicans hyphae, Sec2p is physically associated with SEC2 mRNA on secretory vesicles

andida albicans hyphae grow in a highly polarized fashion from their tips. This polarized growth requires the continuous delivery of secretory vesicles to the tip region. Vesicle delivery depends on Sec2p, the Guanine Exchange Factor (GEF) for the Rab GTPase Sec4p. GTP bound Sec4p is required for the transit of secretory vesicles from the trans-Golgi to sites of polarized growth. We previously showed that phosphorylation of Sec2p at residue S584 was necessary for Sec2p to support hyphal, but not yeast growth. Here we show that on secretory vesicles SEC2 mRNA is physically associated with Sec2p. Moreover, we show that the phosphorylation of S584 allows SEC2 mRNA to dissociate from Sec2p and we speculate that this is necessary for Sec2p function and/or translation. During hyphal extension, the growing tip may be separated from the nucleus by up to 15 μm. Transport of SEC2 mRNA on secretory vesicles to the tip localizes SEC2 translation to tip allowing a sufficient accumulation of this key protein at the site of polarized growth

Barium and Calcium Stimulate Secretion from Digitonin-Permeabilized Bovine Adrenal Chromaffin Cells by Similar Pathways

We compared the characteristics of secretion stimulated by EGTA-buffered Ba 2+ - and Ca 2+ -containing solutions in digitonin-permeabilized bovine adrenal chromaffin cells. Half-maximal secretion occurred at approximately 100 Μ M Ba 2+ or 1 Μ M Ca 2+ . Ba 2+ -stimulated release was not due to release of sequestered intracellular Ca 2+ because at a constant free Ba 2+ concentration, increasing unbound EGTA did not diminish the extent of release due to Ba 2+ . The maximal extents of Ba 2+ - and Ca 2+ -dependent secretion in the absence of MgATP were identical. MgATP enhanced Ba 2+ -induced secretion to a lesser extent than Ca 2+ -induced secretion. Half-maximal concentrations of Ba 2+ and Ca 2+ , when added together to cells, yielded approximately additive amounts of secretion. Maximal concentrations of Ba 2+ and Ca 2+ when added together to cells for 2 or 15 min were not additive. Tetanus toxin inhibited Ba 2+ - and Ca 2+ -dependent secretion to a similar extent. Ba 2+ , unlike Ca 2+ , did not activate polyphosphoinositide-specific phospholipase C. These data indicate that (1) Ba 2+ directly stimulates exocytosis, (2) Ba 2+ -induced secretion is stimulated to a lesser extent than Ca 2+ -dependent secretion by MgATP, (3) Ba 2+ and Ca 2+ use similar pathways to trigger exocytosis, and (4) exocytosis from permeabilized cells does not require activation of polyphosphoinositide-specific phospholipase C.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66323/1/j.1471-4159.1992.tb09771.x.pd