4 resultados para act of a lesser significance
em Duke University
Resumo:
The chemical interplay of nitrogen oxides (NO's) with hemoglobin (Hb) has attracted considerable recent attention because of its potential significance in the mechanism of NO-related vasoactivity regulated by Hb. An important theme of this interplay-redox coupling in adducts of heme iron and NO's-has sparked renewed interest in fundamental studies of FeNO(x) coordination complexes. In this Article, we report combined UV-vis and comprehensive electron paramagnetic resonance (EPR) spectroscopic studies that address intriguing questions raised in recent studies of the structure and affinity of the nitrite ligand in complexes with Fe(III) in methemoglobin (metHb). EPR spectra of metHb/NO(2)(-) are found to exhibit a characteristic doubling in their sharper spectral features. Comparative EPR measurements at X- and S-band frequencies, and in D(2)O versus H(2)O, argue against the assignment of this splitting as hyperfine structure. Correlated changes in the EPR spectra with pH enable complete assignment of the spectrum as deriving from the overlap of two low-spin species with g values of 3.018, 2.122, 1.45 and 2.870, 2.304, 1.45 (values for samples at 20 K and pH 7.4 in phosphate-buffered saline). These g values are typical of g values found for other heme proteins with N-coordinated ligands in the binding pocket and are thus suggestive of N-nitro versus O-nitrito coordination. The positions and shapes of the spectral lines vary only slightly with temperature until motional averaging ensues at approximately 150 K. The pattern of motional averaging in the variable-temperature EPR spectra and EPR studies of Fe(III)NO(2)(-)/Fe(II)NO hybrids suggest that one of two species is present in both of the alpha and beta subunits, while the other is exclusive to the beta subunit. Our results also reconfirm that the affinity of nitrite for metHb is of millimolar magnitude, thereby making a direct role for nitrite in physiological hypoxic vasodilation difficult to justify.
Resumo:
A literature review of howler parasites provides the basis for an overview of the ecological significance of parasite surveys in primates. Within this framework, we have added insights into the interactions between primate hosts and their parasites from a long-term study in Costa Rica. We collected fecal samples from mantled howlers (Alouatta palliata) over a 9-year period (19861994 inclusive) and analyzed them for parasite eggs, larvae, cysts, and oocysts. We found many misperceptions inherent in the typical methodology of primate parasite surveys and in the reporting of the findings. Our work in Costa Rica suggests that a snapshot effect occurs with most surveys. A static view does not reflect the dynamic and changing ecological interaction between host and parasite. We describe some problems with parasite data analyses that emphasize the need for long-term longitudinal surveys in wild primate groups.
Resumo:
In three related experiments, 250 participants rated properties of their autobiographical memory of a very negative event before and after writing about either their deepest thoughts and emotions of the event or a control topic. Levels of emotional intensity of the event, distress associated with the event, intrusive symptoms, and other phenomenological memory properties decreased over the course of the experiment, but did not differ by writing condition. We argue that the act of answering our extensive questions about a very negative event led to the decrease, thereby masking the effects of expressive writing. To show that the changes could not be explained by the mere passage of time, we replicated our findings in a fourth experiment in which all 208 participants nominated a very negative event, but only half the participants rated properties of their memory in the first session. Implications for reducing the effects of negative autobiographical memories are discussed.
Resumo:
*Designated as an exemplary master's project for 2015-16*
This paper examines how contemporary literature contributes to the discussion of punitory justice. It uses close analysis of three contemporary novels, Margaret Atwood’s The Heart Goes Last, Hillary Jordan’s When She Woke, and Joyce Carol Oates’s Carthage, to deconstruct different conceptions of punitory justice. This analysis is framed and supported by relevant social science research on the concept of punitivity within criminal justice. Each section examines punitory justice at three levels: macro, where media messages and the predominant social conversation reside; meso, which involves penal policy and judicial process; and micro, which encompasses personal attitudes towards criminal justice. The first two chapters evaluate works by Atwood and Jordan, examining how their dystopian schemas of justice shed light on top-down and bottom-up processes of punitory justice in the real world. The third chapter uses a more realistic novel, Oates’s Carthage, to examine the ontological nature of punitory justice. It explores a variety of factors that give rise to and legitimize punitory justice, both at the personal level and within a broader cultural consensus. This chapter also discusses how both victim and perpetrator can come to stand in as metaphors to both represent and distract from broader social issues. As a whole, analysis of these three novels illuminate how current and common conceptualizations of justice have little to do with the actual act of transgression itself. Instead, justice emerges as a set of specific, conditioned responses to perceived threats, mediated by complex social, cultural, and emotive forces.
