155 research outputs found
The impact of task difficulty, defendant\u27s race, and race salience on conformity in mock jury deliberations
Understanding what factors affect conformity in jury deliberations is an essential part of understanding the decision making process of reaching a verdict. This study manipulated three variables in a case summary: race salience (not salient vs. salient), defendant race (Black vs. White), and task difficulty (easy vs. difficult). The study used a mock deliberation paradigm based on Kassin, Smith, & Tulloch (1990). Participants read a case summary and provided a verdict with a short explanation. After doing so, participants read notes containing the verdicts and explanations of 5 other fictitious participants. Participants\u27 verdicts were always in the minority. After viewing the decisions of the other participants, the participants were asked to write down a second verdict. In total, there were three rounds of deliberations. Conformity was assessed by number of people who changed their vote in each condition. The participants in this study were college students (N=125). The primary hypothesis was that when the task was unimportant (i.e., the defendant is White), conformity would be equal for the easy and difficult tasks. However, when the task was important (i.e., the defendant is Black), conformity should be higher for the difficult task versus the easy task. This pattern was predicted when race was not salient. The same pattern was predicted for the race salient conditions, however it was anticipated that the effect of task difficulty when the defendant was Black would be amplified. Results provided information about how legally relevant and extralegal variables interact to affect conformity. Aversive racism theories are discussed in the context of the results
Grazing Effects on Deer Mice with Implications to Human Exposure to Sin Nombre Virus
We examined the effects of grazing on deer mouse (Peromyscus maniculatus) movements into buildings using passive integrated transponder (PIT) technology and small simulated buildings located on 0.6-ha treatment (grazing) and control (no grazing) plots. Twelve experimental 9-day trials were conducted over the course of the study. During these trials, mouse movements into buildings were monitored during three time periods (each 3 days in length). In the treatment plots these time periods corresponded to pre-grazing, grazing, and post grazing by horses. The number of individual deer mice entering buildings over time decreased in both the grazed and control plots during the 9 days of each experiment. The number of entrances per/individual among the pre-grazing, grazing and post grazing periods was different between control and treated plots for both males and females. The distribution of entrances/individual among the three periods differed between males and females in both grazed and control plots. The habitat modification caused by grazing appeared to reduce deer mouse activity (entrances/individual) in buildings but does not affect the number of mice entering buildings. Reducing vegetative cover by grazing or mowing may not affect the number of mice investigating small structures but grazing creates different activity patterns in the structures for neighboring deer mice
Effect of Rock Cover on Small Mammal Abundance in a Montana Grassland
We examined the influence of rock cover, as an indicator of presumable retreat site availability on the abundance of deer mice (Peromyscus maniculatus) and prevalence of Sin Nombre virus (SNV) using long-term live trapping and habitat data from three live trapping grids and a shortterm (three month), spatially replicated study across three slopes in Cascade County, Montana. In our long-term study, we found that deer mice were more abundant at a live-trapping grid with greater rock cover, than two grids with less rock cover. There was a non-significant trend (P = 0.053) for deer mice to be more abundant in rocky sites in the short term study. In the long-term study, average SNV antibody prevalence among deer mice was slightly greater (5.0 vs. 3.5 % on average) at the live trapping grid with more rock cover, than the grid with less rock cover. We were unable to demonstrate differences in SNV antibody prevalence among treatments in the short-term study. Further studies are needed to elucidate the multiple determinants of deer mouse abundance and SNV prevalence in grassland ecosystem and other habitat types
Epidemiology and fitness effects of wood mouse herpesvirus in a natural host population
Rodent gammaherpesviruses have become important models for understanding human herpesvirus diseases. In particular, interactions between murid herpesvirus 4 and Mus musculus (a non-natural host species) have been extensively studied under controlled laboratory conditions. However, several fundamental aspects of murine gammaherpesvirus biology are not well understood, including how these viruses are transmitted from host to host, and their impacts on host fitness under natural conditions. Here, we investigate the epidemiology of a gammaherpesvirus in free-living wood mice (Apodemus sylvaticus) and bank voles (Myodes glareolus) in a 2-year longitudinal study. Wood mouse herpesvirus (WMHV) was the only herpesvirus detected and occurred frequently in wood mice and also less commonly in bank voles. Strikingly, WMHV infection probability was highest in reproductively active, heavy male mice. Infection risk also showed a repeatable seasonal pattern, peaking in spring and declining through the summer. We show that this seasonal decline can be at least partly attributed to reduced recapture of WMHV-infected adults. These results suggest that male reproductive behaviours could provide an important natural route of transmission for these viruses. They also suggest that gammaherpesvirus infection may have significant detrimental effects in wild hosts, questioning the view that these viruses have limited impacts in natural, co-evolved host species
Removing Deer Mice from Buildings and the Risk for Human Exposure to Sin Nombre Virus
Trapping and removing deer mice from ranch buildings resulted in an increased number of mice, including Sin Nombre virus antibody–positive mice, entering ranch buildings. Mouse removal without mouse proofing will not reduce and may even increase human exposure to Sin Nombre hantavirus
Exploration of a rare population of Chinese chestnut in North America: stand dynamics, health and genetic relationships
With the transport of plants around the globe, exotic species can readily spread disease to their native relatives; however, they can also provide genetic resistance to those relatives through hybrid breeding programmes. American chestnut (Castanea dentata) was an abundant tree species in North America until its decimation by introduced chestnut blight. To restore chestnut in North America, efforts are ongoing to test putative blight-resistant hybrids of Castanea dentata and Chinese chestnut (Castanea mollissima), but little is known about the ecology of C. mollissima. In a forest in northeastern USA in which C. mollissima has become established, we explored questions of stand dynamics, health and genetic relationships of C. mollissima offspring to an adjacent parent orchard. We found that C. mollissima was adapted and randomly distributed among native species in this relatively young forest. The genetics of the C. mollissima population compared with its parents indicated little effect of selection pressure as each of the parent trees contributed at least one offspring. The ease with which this exotic species proliferated calls to question why C. mollissima is rare elsewhere in forests of North America. It is likely that a time window of low animal predation allowed seedlings to establish, and the shallow soil at this site limited the maximum forest canopy height, permitting the characteristically short-statured C. mollissima to avoid suppression. Our results indicate that because C. mollissima exhibited pioneer species characteristics, hybrids between C. mollissima and C. dentata have the potential to be successful pioneer species of future forests in North America, and we challenge the paradigm that exotic tree species are wholly detrimental to native biodiversity. We contend that exotic tree species should be assessed not only by their level of threat to native species, but also by their potential positive impacts on ecosystems via hybrid breeding programmes
Role of Platelet-Activating Factor and Hypoxia in Persistent Pulmonary Hypertension of the Newborn — Studies with Perinatal Pulmonary Vascular Smooth Muscle Cells
Platelet-activating factor (PAF) plays an important physiological role of maintaining a high vasomotor tone in fetal pulmonary circulation. At birth, endogenous vasodilators such as nitric oxide and prostacyclin are released and facilitate pulmonary vasodilation via cAMP-dependent protein kinase (cAMP/PKA) and cGMP-dependent protein kinase (cGMP/PKG) pathways. Interaction between the cyclic nucleotides and PAF receptor (PAFR)-mediated responses in pulmonary arterial smooth muscle is not well understood. To further understand the interactions of PAF-PAFR pathway and the cyclic nucleotides in ovine fetal pulmonary arterial smooth muscle cells (FPASMC), effects of cAMP and cGMP on PAFR-mediated responses in pulmonary arterial smooth muscle cells (PASMC) were studied. Ovine FPASMC were incubated with 10μM cAMP or cGMP in normoxia (5% CO2 in air, pO2~100 Torr) or hypoxia (2% O2, 5% CO2, pO2~30-40 Torr). Proteins were prepared and subjected to Western blotting. Effect of cell permeable cAMP and cGMP on PAFR binding was also studied and effect of cAMP on cell proliferation was also studied by RNAi to PKA-Cα. cAMP and cGMP significantly decreased PAFR binding and protein expression in normoxia and hypoxia, more so in hypoxia, when PAFR expression was usually high. PKA-Cα siRNA demonstrated that inhibition of PAFR-mediated responses by the cyclic nucleotides occurred through PKA. These data suggest that the normally high levels of cyclic nucleotides in the normoxic newborn pulmonary circulation assist in the downregulation of postnatal PAFR-mediated responses and that under hypoxic conditions, increasing the levels of cyclic nucleotides will abrogate PAF-mediated vasoconstriction thereby ameliorating PAF-induced persistent pulmonary hypertension of the newborn
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California Student Counselors Reflect on a Study Abroad Experience in New Zealand
Seven counseling and guidance students from California participated in a study abroad program in which they were placed in a high school in Auckland, New Zealand, for one month. Their comments on the experience in response to researchers’ questions form the basis of this paper. They suggest that the participants benefited from being immersed in a culturally different context where they had to consider differences in school organization, counseling priorities, and students’ cultural mores. This immersion required them to think about their own professional values and to engage in high level learning, appropriate to masters level field experience work. They commented especially on different approaches to cultural and racial issues in New Zealand and California and on experiencing a counseling profession that is more focused on addressing social issues than on college readiness
Population Density and Seasonality Effects on Sin Nombre Virus Transmission in North American Deermice (Peromyscus maniculatus) in Outdoor Enclosures
Surveys of wildlife host-pathogen systems often document clear seasonal variation in transmission; conclusions concerning the relationship between host population density and transmission vary. In the field, effects of seasonality and population density on natural disease cycles are challenging to measure independently, but laboratory experiments may poorly reflect what happens in nature. Outdoor manipulative experiments are an alternative that controls for some variables in a relatively natural environment. Using outdoor enclosures, we tested effects of North American deermouse (Peromyscus maniculatus) population density and season on transmission dynamics of Sin Nombre hantavirus. In early summer, mid-summer, late summer, and fall 2007–2008, predetermined numbers of infected and uninfected adult wild deermice were released into enclosures and trapped weekly or bi-weekly. We documented 18 transmission events and observed significant seasonal effects on transmission, wounding frequency, and host breeding condition. Apparent differences in transmission incidence or wounding frequency between high- and low-density treatments were not statistically significant. However, high host density was associated with a lower proportion of males with scrotal testes. Seasonality may have a stronger influence on disease transmission dynamics than host population density, and density effects cannot be considered independent of seasonality
The truth about snitches: an archival analysis of informant testimony
Informants are witnesses who often testify in exchange for an incentive (i.e. jailhouse informant, cooperating witness). Despite the widespread use of informants, little is known about the circumstances surrounding their use at trial. This study content-analyzed trials from 22 DNA exoneration cases involving 53 informants. Because these defendants were exonerated, the prosecution informant testimony is demonstrably false. Informant characteristics including motivation for testifying, criminal history, relationship with the defendant and testimony were coded. Most informants were prosecution jailhouse informants; however, there were also defence jailhouse informants and prosecution cooperating witnesses. Regardless of informant type, most denied receiving an incentive, had criminal histories, were friends/acquaintances of the defendant and had testimonial inconsistencies. In closing statements, attorneys relied on informant testimony by either emphasizing or questioning its reliability. The impact of informant testimony on jurors’ decisions is discussed in terms of truth-default theory (TDT), the fundamental attribution error and prosecutorial vouching
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