520 research outputs found
A commentary on the Synopsis Fungorum in America Boreali Media Degentium, by L. D. de Schweinitz
Cueing Visual Spatial Working Memory: Effects of Cue Modality, Cue Type, and Age
In general, attentional control and spatial working memory (WM) decline with increasing age. It is well known that relative to non-cued targets, spatially informative visual (uni-modal) cues quicken response time in target detection attention tasks, and improve feature and spatial WM performance. Spatially informative auditory and vibrotactile (cross-modal) cues provide additional benefit in more difficult attention tasks, but their effects on spatial location WM are unknown. This dissertation presents two studies that investigated effects of uni-modal visual cues and cross-modal auditory and vibrotactile cues on visual spatial location WM in younger adults (YA) and older adults (OA), and under various conditions that modulated WM task demands. In study one, we found that both spatially informative uni-modal and cross-modal cues improved spatial location WM performance to a similar degree for YA and OA. This benefit was generally greater under higher WM load (i.e., six-item vs. four-item memory arrays) and longer maintenance delays, whereas centrally presented alerting cues generally impaired performance. Individuals with lower spatial spans also benefitted most from spatially informative cross-modal cues. Study two assessed the impact of maintenance interference on spatially informative cue effects. In contrast to study one, we found age-related cue effects, which were moderated by WM maintenance interference type. When interference was to be ignored, OA benefitted from visual, auditory, and vibrotactile cues for lower WM loads (i.e., four-item arrays), whereas YA only benefitted from vibrotactile cues at higher WM loads (i.e., six-item arrays). When interference was to be compared, OA showed increased benefit to WM performance from cross-modal auditory and vibrotactile cues, whereas YA benefitted from all cue modalities. Taken together, these findings suggest spatially informative cross-modal cues can improve spatial location WM in both YA and OA, particularly when demands on spatial attention and attentional control are high. Furthermore, OA show more consistent benefit from cross-modal cues in resource demanding conditions. These results provide insight into cognitive underpinnings of cross-modal cue effects, and age-related differences in use of environmental support. They also provide a rationale for real world applications using cross-modal cues, aimed at improving cognitive function in complex visual environments, particularly for OA
Sex and age at death estimation from the os pubis: validation of two methods on a modern autopsy sample
Estimating sex and age at death are two crucial processes during the creation of a biological profile for a set of skeletal remains. Whether the remains are archaeological or forensic, estimating the sex and age of the individual is necessary for further analysis and interpretation. Specifically, in a medicolegal context, knowing the biological sex and approximate age of the remains assists law enforcement or government agencies in identifying unknown individuals. Since the inception of the field of forensic anthropology, practitioners have been developing methods to perform the aforementioned tasks. It is crucial that these methods be consistent, repeatedly tested, validated, and improved for multiple reasons. Firstly, to conform to Daubert (1993) standards, and additionally, to make sure that they are accurate and applicable to modern forensic cases. The present study was performed to validate the efficacy of the method for estimating sex from the os pubis originally proposed in Klales et al. (2012), as well as the efficacy of the “transition analysis” method for estimating age, originally outlined in Boldsen et al. (2002).
Considering the recent popularity of using these methods to create a biological profile for forensic cases, it is necessary to develop error rates on a large, modern, American autopsy sample. These two methods are not only being readily utilized, but are additionally being taught to students in training. The utilization of these models involves a “logistic regression model” created by Klales et. al (2012) to process ordinal scores, and the Bayesian statistics software program “ADBOU” that was created for processing data collected using the method in Boldsen et. al (2002). These statistical systems which produced age estimates are relatively young compared to methods developed for the same purpose. The new generation of forensic anthropologists is fully responsible for objectively critiquing and validating these methods that are being disseminated by their professors and senior practitioners. The goal of the present study is to do just that. A skeletal reference sample of 630 pubic bones, all removed from modern autopsy cases and housed at the Maricopa County Forensic Science Center in Phoenix, Arizona, was utilized for data collection in the present study. Each pubic bone was assessed and scored according to the exact instructions outlined in the materials for each method, which was the Klales et al. (2012) paper for sex estimation, and the UTK Data Collection Procedures for Forensic Skeletal Material 2.0 for age estimation (Langley et al. 2016). Additionally, the observers recorded their “gestalt” estimates for sex using the Phenice (1969) system, as well as Brooks and Suchey (1990) and Hartnett (2010a) phases for each pubis. Demographic information labels were hidden, and the collection demographic information was not viewed until the completion of data collection.
The null hypothesis in the present study is that both methods (the Klales et al. method (2012) and “transition analysis” method (Boldsen et al. 2002) will perform as well as they did in the original studies. The alternate hypothesis is that they do not result in the same accuracy rates reported in the original studies. Statistical analysis of the data indicates that there is sufficient evidence to reject the null hypothesis as it applies to the Klales et al. (2012) method. The classification accuracies achieved applying the logistic regression equation to the sample of pubic bones was found to be significantly lower than reported in the original study (86.2%), averaging around 70% between observers. The level of both intraobserver and interobserver agreement was only moderate for this method. It was also found that asymmetry occurred in some individuals, producing differing estimates of sex when the left and right pubes were scored separately. When utilizing the Boldsen et al. (2012) method and the ADBOU software package on only pubic symphyseal components to estimate age, the method was found to perform reasonably well. The majority (about 82%) of individuals had actual ages at death that fell within the predicted range produced by the statistical analysis. The majority of the symphyseal component scores showed moderate to good levels of interobserver agreement, and the estimated maximum likelihood (point estimate) of age at death predicted by the software package correlated moderately well with the actual age of death of the individual. These methods did not perform as well as reported in the original studies, and they should be further validated and recalibrated to improve their accuracy and reliability
Curriculum Platform Needs: Assessment for AICCRA Partners
This report summarizes findings on needs and gaps for a key activity of the AICCRA project-development of a curriculum platform. The AICCRA curriculum platform will be a resource that enables institutions to establish and continually develop curricula that support key competencies/skills in climate services/CSA prioritized by stakeholders in regions
Low Molecular Weight Fluorescent Probes (LMFPs) to Detect the Group 12 Metal Triad
Fluorescence sensing, of d-block elements such as Cu2+, Fe3+, Fe2+, Cd2+, Hg2+, and Zn2+ has significantly increased since the beginning of the 21st century. These particular metal ions play essential roles in biological, industrial, and environmental applications, therefore, there has been a drive to measure, detect, and remediate these metal ions. We have chosen to highlight the low molecular weight fluorescent probes (LMFPs) that undergo an optical response upon coordination with the group 12 triad (Zn2+, Cd2+, and Hg2+), as these metals have similar chemical characteristics but behave differently in the environment
Spatial analysis of plague in California: niche modeling predictions of the current distribution and potential response to climate change
<p>Abstract</p> <p>Background</p> <p>Plague, caused by the bacterium <it>Yersinia pestis</it>, is a public and wildlife health concern in California and the western United States. This study explores the spatial characteristics of positive plague samples in California and tests Maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. Maxent models were constructed using geocoded seroprevalence data from surveillance of California ground squirrels (<it>Spermophilus beecheyi</it>) as case points and Worldclim bioclimatic data as predictor variables, and compared and validated using area under the receiver operating curve (AUC) statistics. Additionally, model results were compared to locations of positive and negative coyote (<it>Canis latrans</it>) samples, in order to determine the correlation between Maxent model predictions and areas of plague risk as determined via wild carnivore surveillance.</p> <p>Results</p> <p>Models of plague activity in California ground squirrels, based on recent climate conditions, accurately identified case locations (AUC of 0.913 to 0.948) and were significantly correlated with coyote samples. The final models were used to identify potential plague risk areas based on an ensemble of six future climate scenarios. These models suggest that by 2050, climate conditions may reduce plague risk in the southern parts of California and increase risk along the northern coast and Sierras.</p> <p>Conclusion</p> <p>Because different modeling approaches can yield substantially different results, care should be taken when interpreting future model predictions. Nonetheless, niche modeling can be a useful tool for exploring and mapping the potential response of plague activity to climate change. The final models in this study were used to identify potential plague risk areas based on an ensemble of six future climate scenarios, which can help public managers decide where to allocate surveillance resources. In addition, Maxent model results were significantly correlated with coyote samples, indicating that carnivore surveillance programs will continue to be important for tracking the response of plague to future climate conditions.</p
Intersecting race and gender stereotypes:Implications for group-level attitudes
Two studies examined the relationship between explicit stereotyping and prejudice by investigating how stereotyping of minority men and women may be differentially related to prejudice. Based on research and theory related to the intersectional invisibility hypothesis (Purdie-Vaughns & Eibach, 2008), we hypothesized that stereotyping of minority men would be more strongly related to prejudice than stereotyping of minority women. Supporting our hypothesis, in both the United Kingdom (Study 1) and the United States (Study 2), when stereotyping of Black men and women were entered into the same regression model, only stereotyping of Black men predicted prejudice. Results were inconsistent in regard to South Asians and East Asians. Results are discussed in terms of the intersectional invisibility hypothesis (Purdie-Vaughns & Eibach, 2008) and the gendered nature of the relationship between stereotyping and attitudes
iPhone in NASA Ground Operations
A comprehensive review of the literature and historical background of NASA established a need for an easy-to-implement technological improvement to displaying procedures which is cost effective and risk reducing. Previous unsuccessful attempts have led this team to explore the practicality of using a mobile handheld device. The major products, inputs, resources, constraints, planning and effort required for consideration of this type of solution were outlined. After analyzing the physical, environmental, life-cycle, functional, and socio-technical requirements, a Functional Analysis was performed to describe the top-level, second-level, and third-level functions of the system requirements. In addition, the risk/value proposition of conversion to a new technology was considered and gave a blueprint for transitioning along with the tasks necessary to implement the device into the Vehicle Assembly Building's (VAB) current infrastructure. A Work Breakdown Structure (WBS) described the elemental work items of the implementation. Once the viability of this system was confirmed, a device was selected through use of technical design comparison methods including the Pugh Matrix and House of Quality. Comparison and evaluation of the Apple iPhone, Motorola Q, Blackberry, PC Notebook, and PDA revealed that the iPhone is the most suitable device for this task. This paper outlines the device design/ architecture, as well as some of the required infrastructure
Urinary Levoglucosan as a Biomarker for Wood Smoke: Results of Human Exposure Studies
Urinary levoglucosan was investigated as a potential biomarker for wood smoke exposure in two different controlled experimental settings. Nine subjects were exposed to smoke from a campfire in a controlled setting and four were exposed to smoke from an older model wood stove. All subjects were asked to provide urine samples before and after exposure, and to wear personal PM2.5 monitors during the exposure. Urinary levoglucosan measurements from both studies showed no consistent response to the smoke exposure. A third experiment was conducted to assess the contribution of dietary factors to urinary levoglucosan levels. Nine subjects were asked to consume caramel and provide urine samples before and after consumption. Urinary levoglucosan levels increased within 2 hours of caramel consumption and returned to pre-exposure levels within 24 hours. These studies suggest that diet is a major factor in determining urinary levoglucosan levels and recent dietary history needs to be taken into account for future work involving levoglucosan as a biomarker of wood smoke exposure
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