15 research outputs found

    An Application of Wavelets to Finance: The Three-Factor Fama/French Model

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    We use multi-scale analysis and a rolling 250-day window to estimate a widely used standard for empirical asset pricing. The asset pricing model employed is the Fama-French three-factor model. The model is estimated using stock returns for 49 industry stocks of US industry portfolios for the period from July 1969 to September 2017. The rolling window estimation approach allows us to capture the behavior of an investor who periodically reallocates his portfolio. Employing periodic estimates of expected return, we implement a set of long/short investment strategies based on the standard Fama-French three-factor model, and scale versions of the model. We find that during recessions, the higher scale long/short strategies tend to outperform the standard approach. Our results suggest distinct risk dynamics at specific horizons during recessions. We conclude that the information content of the economic phenomena that generate the three-factor model does not follow strict periodicity during recessions, making the wavelet approach more suitable for portfolio managers who must be prepared to rebalance portfolios during official downturns

    Uncertainty and the Oracle of Market Returns: Evidence from Wavelet Coherence Analysis

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    Wavelet methodology is employed to investigate the statistical relationship between three well-accepted measures of uncertainty and both market and sector returns. Our primary goal is to determine whether uncertainty is sector specific. Although there are periods when the market works effectively as an oracle capturing uncertainty, we also find sector specific uncertainty. The wavelet equivalent of correlation, coherence, is used to determine the presence of sector specific uncertainty. We find that allowing localized information in the time frequency domain is critical for separating out sector specific uncertainty from market uncertainty

    Efficient DNA Profiling Protocols for Disaster Victim Identification

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    Advances in forensic biology have increased the options for the collection, sampling, preservation and processing of human remains for DNA-based identification. Combined with a plethora of commercial DNA testing kits that are far more forgiving of inhibited and degraded samples, efficient DNA approaches to post-mortem samples are explored here for DNA-based identification of compromised human remains. Approaches which preserve sample and reduce analytical turnaround times whilst saving resources also have the potential to expedite the identification process, to provide answers to grieving families sooner, or to provide leads in a criminal investigation. Targeting sample types that are minimally-invasive and do not require extensive preparation and testing protocols also has benefit for disaster victim identification (DVI) by facilitating field sampling. We have assessed minimally-invasive and simple to collect sample types compatible with minimal pre-treatment and efficient DNA profiling approaches. Incubating nail, distal phalanges and whole digits in 500 µL of PrepFiler™ Lysis Buffer for 2 h was an efficient and simple method, limiting or removing sample preparation. A reduced 15 min incubation also yielded DNA profiles suggesting a shorter incubation may lyse sufficient DNA. Preservative solutions offer an even simpler process in some cases. Furthermore, the efficient approaches described in this study offer storage solutions and are compatible with backend automated processing. This study will inform further research to develop and optimise efficient protocols. These DNA approaches should not be pursued for every sample; more compromised samples may best be submitted to the laboratory for more effective extraction and genotyping.</jats:p

    Current and emerging tools for the recovery of genetic information from post mortem samples: New directions for disaster victim identification

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    © 2018 Elsevier B.V. DNA profiling has emerged as the gold standard for the identification of victims in mass disaster events providing an ability to identify victims, reassociate remains and provide investigative leads at a relatively low cost, and with a high degree of discrimination. For the majority of samples, DNA-based identification can be achieved in a fast, streamlined and high-throughput manner. However, a large number of remains will be extremely compromised, characteristic of mass disasters. Advances in technology and in the field of forensic biology have increased the options for the collection, sampling, preservation and processing of samples for DNA profiling. Furthermore, recent developments now allow a vast array of new genetic markers and genotyping techniques to extract as much genetic information from a sample as possible, ensuring that identification is not only accurate but also possible where material is degraded, or limited. Where historically DNA profiling has involved comparison with ante mortem samples or relatives, now DNA profiling can direct investigators towards putative victims or relatives, for comparison through the determination of externally visible characteristics, or biogeographical ancestry. This paper reviews the current and emerging tools available for maximising the recovery of genetic information from post mortem samples in a disaster victim identification context

    Automating direct-to-PCR for disaster victim identification

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    © 2019, © 2019 Australian Academy of Forensic Sciences. Direct-to-PCR methodology adds samples directly to PCR tubes offering gains in efficiency and sensitivity. The approach has been applied to a variety of biological sources including blood, saliva, tissue, hair and nail. We added various preservative solutions to a range of biological samples to leech DNA into solution, whilst preserving at room temperature. Tubes containing ‘free DNA’ then followed automated workflows for amplification and capillary electrophoresis. Routine FASS-automated workflows (including DNA extraction and quantification) were compared with published direct-to-PCR methodology and automated amplification of an aliquot of preservative solution. Applying preservative solutions to ~30-year-old blood stains stored at room temperature resulted in recovery of a larger quantity of DNA and more alleles (using PowerPlex 21) when compared with routine automated typing. Trials were extended to blood, saliva, hair and nail, mimicking ante-mortem samples collected in a disaster victim identification effort. Despite slightly lower allelic recovery, the faster processing times, lower costs and storage potential offers advantages for the processing of ante-mortem samples

    An in-field evaluation of rapid DNA instruments for disaster victim identification.

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    In 2019 and 2020, disaster victim identification (DVI) simulations were conducted at the Australian Facility for Taphonomic Experimental Research. Whole and fragmented cadavers were positioned to replicate a building collapse scenario and left to decompose for up to 4 weeks. This study evaluated the utility of the ANDE™ 6C Rapid DNA System and the RapidHITTM ID System for DVI in the field and mortuary. Applying post-mortem nail and tissue biopsy samples showed promise, with the added benefit of minimally invasive collection procedures and limited preparation requirements. The preferred platform will depend on a number of factors, including its intended use and operating environment

    Direct to PCR tissue preservation for DNA profiling

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    Disaster victim identification (DVI) often occurs in remote locations with extremes of temperatures and humidities. Access to mortuary facilities and refrigeration are not always available. An effective and robust DNA sampling and preservation procedure would increase the probability of successful DNA profiling and allow faster repatriation of bodies and body parts. If the act of tissue preservation also released DNA into solution, ready for polymerase chain reaction (PCR), the DVI process could be further streamlined. In this study, we explored the possibility of obtaining DNA profiles without DNA extraction, by adding aliquots of preservative solutions surrounding fresh human muscle and decomposing human muscle and skin tissue samples directly to PCR. The preservatives consisted of two custom preparations and two proprietary solutions. The custom preparations were a salt-saturated solution of dimethyl sulfoxide (DMSO) with ethylenediaminetetraacetic (EDTA) and TENT buffer (Tris, EDTA, NaCl, Tween 20). The proprietary preservatives were DNAgard (Biomatrica(A (R))) and Tissue Stabilising Kit (DNA Genotek). We obtained full PowerPlex(A (R)) 21 (Promega) and GlobalFiler(A (R)) (Life Technologies) DNA profiles from fresh and decomposed tissue preserved at 35 A degrees C for up to 28 days for all four preservatives. The preservative aliquots removed from the fresh muscle tissue samples had been stored at -80 A degrees C for 4 years, indicating that long-term archival does not diminish the probability of successful DNA typing. Rather, storage at -80 A degrees C seems to reduce PCR inhibition

    Direct-to-PCR tissue preservation for DNA profiling.

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    Disaster victim identification (DVI) often occurs in remote locations with extremes of temperatures and humidities. Access to mortuary facilities and refrigeration are not always available. An effective and robust DNA sampling and preservation procedure would increase the probability of successful DNA profiling and allow faster repatriation of bodies and body parts. If the act of tissue preservation also released DNA into solution, ready for polymerase chain reaction (PCR), the DVI process could be further streamlined. In this study, we explored the possibility of obtaining DNA profiles without DNA extraction, by adding aliquots of preservative solutions surrounding fresh human muscle and decomposing human muscle and skin tissue samples directly to PCR. The preservatives consisted of two custom preparations and two proprietary solutions. The custom preparations were a salt-saturated solution of dimethyl sulfoxide (DMSO) with ethylenediaminetetraacetic (EDTA) and TENT buffer (Tris, EDTA, NaCl, Tween 20). The proprietary preservatives were DNAgard (Biomatrica(®)) and Tissue Stabilising Kit (DNA Genotek). We obtained full PowerPlex(®) 21 (Promega) and GlobalFiler(®) (Life Technologies) DNA profiles from fresh and decomposed tissue preserved at 35 °C for up to 28 days for all four preservatives. The preservative aliquots removed from the fresh muscle tissue samples had been stored at -80 °C for 4 years, indicating that long-term archival does not diminish the probability of successful DNA typing. Rather, storage at -80 °C seems to reduce PCR inhibition

    From multiculturalism to post-multiculturalism: Trends and paradoxes

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    In recent years, multiculturalism has been declared a failure both in Europe and the Anglophone West. This diagnosis went hand in hand with an excessive focus on gendered cultural practices in culturally diverse societies, such as forced marriages or ¿honour killings¿; the raise of anti-immigration political movements and the adoption of stricter legal rules in the areas of immigration and citizenship. This article aims to capture the legal, social and political responses to ¿failed¿ multiculturalism under the banner of post-multiculturalism. In doing so, it identifies the major shifts that characterises post-multiculturalism and discusses their implications particularly for the citizens of Europe and various ¿others¿. A close analysis of the recent shifts in the areas of rights, migration law and policy debates in various culturally diverse societies reveal that post-multiculturalism reinforces rather than counteracts the problematic features of multiculturalism. Drawing on the insights suggested by the literature on neo-liberal governmentality, the article points out the paradoxes of post-multiculturalism and their implications for culturally different Others
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