6,391 research outputs found
A forensic geoscience framework and practice
Appropriate and correct collection, analysis, interpretation, and presentation of geoforensic evidence are contingent upon understanding the specific context of the particular forensic investigation undertaken. To achieve this, the role of experimental studies in forensic geoscience must not be underestimated. In this article, we present two experimental studies that assess the spatial distribution of pollen in a living room and the nature of subsequent transfer of pollen onto clothing. The presence of cut flowers in a living room are shown to lead to a distribution of pollen grains onto all types of surface in that room that exhibits a distanceādecay pattern with the greatest numbers of grains found in close proximity to the flowers. Once the transfer of pollen grains from a source location onto clothing has taken place, our second study demonstrates the nature of the persistence of that evidence for dry and damp clothing under active and inactive conditions. The level of activity after transfer is shown to have far more influence upon the persistence of this form of geoforensic evidence in comparison to the damp or dry conditions of the garment. We argue that these findings have implications for all stages of the forensic investigationāfrom sampling protocols to the interpretation of the presence/absence of geoforensic evidence. Whilst every contact does indeed leave a trace, it is imperative that there is an appreciation of the context of each forensic investigation, meaningful science take place and accurate and helpful crime reconstructions to be achieved
Comparison of Different Boost Transformations for the Calculation of Form Factors in Relativistic Quantum Mechanics
The effect of different boost expressions, pertinent to the instant, front
and point forms of relativistic quantum mechanics, is considered for the
calculation of the ground-state form factor of a two-body system in simple
scalar models. Results with a Galilean boost as well as an explicitly covariant
calculation based on the Bethe-Salpeter approach are given for comparison. It
is found that the present so-called point-form calculations of form factors
strongly deviate from all the other ones. This suggests that the formalism
which underlies them requires further elaboration. A proposition in this sense
is made.Comment: Invited talk given at the 18th European Conference on Few-Body
Problems in Physics, Bled, Slovenia, 8-14 Sep 2002. Submitted to Few Body
Syst.Supp
Erratum: A decadal decline in relative abundance and a shift in microphytoplankton composition at a long-term coastal station off southeast Australia
In this study, we examined 11 yr (1998-2009) of water samples collected from Port Hacking coastal monitoring station 8 km offshore from Sydney, Australia, to assess changes in the microphytoplankton in relation to climate-related trends in environmental variables. A total of 152 taxa (85 genera) were identified, with the small diatom Thalassiosira cf. partheneia and the tropical cyanobacterium Trichodesmium erythraeum being the dominant species over the past decade. Taxon richness showed a distinct seasonal pattern, peaking in the austral winter. Ordination analyses revealed significant seasonal and interannual trends in species composition, including a decadal decline in dinoflagellates relative to diatoms toward the present. This decadal shift in taxonomic composition was, in turn, significantly associated with declines in water temperatures over this time period. Total abundance varied by 12 orders of magnitude (8.5 X 10ā»āø to 7.4 X 10ā“ cells Lā»Ā¹), with values separable into bloom and nonbloom regimes at an abundance threshold of 7.1 X 10ā»āµ cells Lā»Ā¹. Significant temporal declines in abundance were observed during both bloom and nonbloom regimes. Blooms occurred most consistently in March, September, and December.13 page(s
Adapting the Implicit Association Test to Health Professions Education May Lead to Improving American Indian Health
The Implicit Association Test (IAT) has been supported as a valid means for demonstrating implicit biases in racial/ethnic studies; however, adaption of the IAT for evaluation of unconscious biases against American Indians has not previously been reported. The authors conducted a study addressing validity of the IAT for measurement of implicit bias against American Indians in a health education setting, its value in providing information not revealed by explicit measures, and the association between demographic characteristics of health professions student groups and their IAT scores. The paper-format IAT instrument designed was piloted at an Oklahoma institution with health professions students. The American Indian participant group demonstrated an implicit preference for American Indian over Caucasian surnames by faster association of American Indian surnames with good versus bad attribute exemplars. Demonstration of predictable implicit response patterns that varied from explicit responses provided evidence for the value of adaptation of an IAT to evaluate American Indian bias. American Indian implicit bias research with health care professionals and students using the IAT may provide a valuable means for reaching the ultimate goal of improving health care for American Indians and thereby improving the health of American Indian tribal communities
Climatic Disequilibrium Threatens Conservation Priority Forests
AcceptedArticle in PressThis is the final version of the article. Available from Wiley Open Access via the DOI in this record.Ā© 2017 Wiley Periodicals, Inc.We test the hypothesis that climatic changes since 1800 have resulted in unrealized potential vegetation changes that represent a "climatic debt" for many ecosystems. Caledonian pinewoods, an EU priority forest type, are used as a model system to explore potential impacts of two centuries of climatic change upon sites of conservation importance and surrounding landscapes. Using methods that estimate topographic microclimate, current and preindustrial climates were estimated for 50 m grid cells and simulations made using a dynamic vegetation model. Core Caledonian pinewood areas are now less suitable for growth of pine and more favorable for oak than in 1800, whereas landscapes as a whole are on average more favorable for both. The most favorable areas for pine are now mainly outside areas designated to conserve historical pinewoods. A paradigm shift is needed in formulating conservation strategies to avoid catastrophic losses of this habitat, and of many others globally with trees or other long-lived perennials as keystone species.Natural Environment Research Council. Grant Number: NE/I011234/
HLA Class-II Associated HIV Polymorphisms Predict Escape from CD4+ T Cell Responses.
Antiretroviral therapy, antibody and CD8+ T cell-mediated responses targeting human immunodeficiency virus-1 (HIV-1) exert selection pressure on the virus necessitating escape; however, the ability of CD4+ T cells to exert selective pressure remains unclear. Using a computational approach on HIV gag/pol/nef sequences and HLA-II allelic data, we identified 29 HLA-II associated HIV sequence polymorphisms or adaptations (HLA-AP) in an African cohort of chronically HIV-infected individuals. Epitopes encompassing the predicted adaptation (AE) or its non-adapted (NAE) version were evaluated for immunogenicity. Using a CD8-depleted IFN-Ī³ ELISpot assay, we determined that the magnitude of CD4+ T cell responses to the predicted epitopes in controllers was higher compared to non-controllers (p<0.0001). However, regardless of the group, the magnitude of responses to AE was lower as compared to NAE (p<0.0001). CD4+ T cell responses in patients with acute HIV infection (AHI) demonstrated poor immunogenicity towards AE as compared to NAE encoded by their transmitted founder virus. Longitudinal data in AHI off antiretroviral therapy demonstrated sequence changes that were biologically confirmed to represent CD4+ escape mutations. These data demonstrate an innovative application of HLA-associated polymorphisms to identify biologically relevant CD4+ epitopes and suggests CD4+ T cells are active participants in driving HIV evolution
Recommended from our members
Measuring venous oxygenation using the photoplethysmograph waveform
OBJECTIVE: We investigate the hypothesis that the photoplethysmograph (PPG) waveform can be analyzed to infer regional venous oxygen saturation.
METHODS: Fundamental to the successful isolation of the venous saturation is the identification of PPG characteristics that are unique to the peripheral venous system. Two such characteristics have been identified. First, the peripheral venous waveform tends to reflect atrial contraction. Second, ventilation tends to move venous blood preferentially due to the low pressure and high compliance of the venous system. Red (660 nm) and IR (940 nm) PPG waveforms were collected from 10 cardiac surgery patients using an esophageal PPG probe. These waveforms were analyzed using algorithms written in Mathematica. Four time-domain saturation algorithms (ArtSat, VenSat, ArtInstSat, VenInstSat) and four frequency-domain saturation algorithms (RespDC, RespAC, Cardiac, and Harmonic) were applied to the data set.
RESULTS: Three of the algorithms for calculating venous saturation (VenSat, VenInstSat, and RespDC) demonstrate significant difference from ArtSat (the conventional time-domain algorithm for measuring arterial saturation) using the Wilcoxon signed-rank test with Bonferroni correction (p < 0.0071).
CONCLUSIONS: This work introduces new algorithms for PPG analysis. Three algorithms (VenSat, VenInstSat, and RespDC) succeed in detecting lower saturation blood. The next step is to confirm the accuracy of the measurement by comparing them to a gold standard (i.e., venous blood gas)
The spatial and temporal distribution of pollen in a room: forensic implications.
This paper presents two experimental studies that deal with the spatial and temporal distribution of pollen grains within a room of a domestic dwelling. The findings concur with the preliminary work of Morgan et al. [1] and provide greater detail as to the behaviour of pollen grains within indoor locations that are pertinent for forensic investigations. The spatial distribution of pollen in a room exhibits strong distance decay trends, with the majority of pollen recovered within 0.8m of its source. The pollen was found to persist in increasing quantities during the time the flowers were in the room. This study also shows that 20days after the flowers were removed, 25-32% of the original pollen was still present within the room. The influence of disturbance was investigated and whilst areas of high disturbance were found to retain less pollen than undisturbed locations, the influence of the proximity to source was a more dominant factor. These findings have significant implications for forensic investigation protocols, particularly the collection and interpretation phases of trace evidence analysis. The distribution of pollen around a room ensures that viable sources of trace pollen are available for transfer if contact is made between a location in the room and a suspect. The persistence of pollen many days after the flowers have been removed from a room indicates that many rooms in domestic dwellings will have distinctive assemblages that reflect the history of the flowers that have been displayed within that room in the past, and that these assemblages will persist and therefore be available for transfer. These preliminary findings indicate that investigation by forensic palynology in indoor domestic settings may well be an underutilised technique that has the potential to provide accurate and valuable intelligence and evidence for forensic enquiry
Real Lives and White Lies in the Funding of Scientific Research: The granting system turns young scientists into bureaucrats and then betrays them
- ā¦