Quantified Explosives Transfer on Surfaces for the Evaluation of Trace Detection Equipment

Trace explosive test surfaces are often required for the evaluation of trace detection equipment to determine the equipment performance. Test surfaces of C‐4, Detasheet, Semtex‐H, TNT, and HMTD were prepared by transferring trace amount of explosive deposited on polytetrafluoroethylene (PTFE) transfer strips onto different surfaces (Kraft paper, hard plastic, woven fabric, and soft vinyl). The amount of explosive transferred was deduced from the amount of explosive remaining on the PTFE strips after transfer, as quantified by direct analysis using tandem mass spectrometry with thermal desorption. From the data set of over 2000 transfers, we experienced lower transfer efficiency for Semtex‐H and Detasheet, and for soft vinyl and hard plastic. However, the rapid quantification mass spectrometric method allowed the transfer efficiency to be determined for all test surfaces used in an evaluation of trace explosive detectors, thereby permitting only the test surfaces with desired transfer to be accepted for the assessment.     

New estimates of U.S. currency abroad,the domestic money supply and the unreported economy

Despite financial innovations that have created important new substitutes for cash usage, per capita holdings of U.S. currency amount to $2950. Yet American households and businesses admit to holding only 15% of the currency stock, leaving the whereabouts of 85% unknown. Some fraction of this unaccounted for currency is held abroad (the dollarization hypothesis) and some is held domestically undeclared, as a store of value and a medium of exchange for transactions involving the production and distribution of illegal goods and services, and for transactions earning income that is not reported to the IRS (the unreported economy hypothesis). We find that the percentage of U.S. currency currently held overseas is between 30 and 37% rather than the widely cited figure of 65%. This finding is based on the official Federal Reserve/Bureau of Economic Analysis data which is a proxy measure of the New York Federal Reserve’s (NYB) “confidential” data on wholesale currency shipments abroad. We recommend that the NYB data be aggregated so as to circumvent confidentiality concerns, and be made readily available to all researchers in order to shed greater light on the questions of how much U.S. currency is abroad and on the particular location of overseas U.S. dollars. The newly revised official estimates of overseas currency holdings are employed to determine the Federal Reserve’s seigniorage earnings from 1964–2010, which have provided a $2950. Yet American households and businesses admit to holding only 15% of the currency stock, leaving the whereabouts of 85% unknown. Some fraction of this unaccounted for currency is held abroad (the dollarization hypothesis) and some is held domestically undeclared, as a store of value and a medium of exchange for transactions involving the production and distribution of illegal goods and services, and for transactions earning income that is not reported to the IRS (the unreported economy hypothesis). We find that the percentage of U.S. currency currently held overseas is between 30 and 37% rather than the widely cited figure of 65%. This finding is based on the official Federal Reserve/Bureau of Economic Analysis data which is a proxy measure of the New York Federal Reserve’s (NYB) “confidential” data on wholesale currency shipments abroad. We recommend that the NYB data be aggregated so as to circumvent confidentiality concerns, and be made readily available to all researchers in order to shed greater light on the questions of how much U.S. currency is abroad and on the particular location of overseas U.S. dollars. The newly revised official estimates of overseas currency holdings are employed to determine the Federal Reserve’s seigniorage earnings from 1964–2010, which have provided a 287 billion windfall for U.S. taxpayers. Overseas currency stock data are also used to derive estimates of the domestically held stock of currency as well as narrow and broad measures of domestic monetary aggregates. These domestic monetary aggregates are believed to be better predictors of future economic activity than traditional monetary aggregates and are tested to determine their ability to predict fluctuations in real output and prices. Domestic cash holdings are finally used to estimate the size of the U.S. unreported economy as measured by the amount of income that is not properly reported to the IRS. By 2010, we estimate that legal and illegal source unreported income” is $1.9–$1.9–2.4 trillion, implying a “tax gap” in the range of $400–$400–540 billion. Currently, we estimate that 18–23% of total reportable income is not properly reported to the IRS.     

Drug contamination of US paper currency

It is known that US paper currency in the general circulation is contaminated with cocaine. Several mechanisms have been offered to explain this finding, including contamination due to handling during drug deals and the use of rolled up bills for snorting. Drug is then transferred from one contaminated bill to others during counting in financial institutions. The possibility of contamination of currency with other drugs has not been reported. In this study, the author reports the analysis of 10 randomly collected US$ 1 bills from five cities, for cocaine, heroin, 6-acetylmorphine (6-AM), morphine, codeine, methamphetamine, amphetamine and phencyclidine (PCP). Bills were immersed in acetonitrile for 2h prior to extraction and GC-MS analysis. Results showed that 92% of the bills were positive for cocaine with a mean amount of 28.75+/-139.07 microg per bill, a median of 1.37 microg per bill, and a range of 0.01-922.72 microg per bill. Heroin was detected in seven bills in amounts ranging from 0.03 to 168.50 microg per bill: 6-AM and morphine were detected in three bills; methamphetamine and amphetamine in three and one bills, respectively, and PCP was detected in two bills in amounts of 0.78 and 1.87 microg per bill. Codeine was not detected in any of the US$ 1 bills analyzed. This study demonstrated that although paper currency was most often contaminated with cocaine, other drugs of abuse may be detected in bills.     

Detection of Anthrax and Other Pathogens Using a Unique Liquid Array Technology

A bead‐based liquid hybridization assay, Luminex^® 100?, was used to identify four pathogenic bacteria, Bacillus anthracis, Clostridium botulinum, Francisella tularensis subsp. tularensis, and Yersinia pestis, and several close relatives. Hybridization between PCR‐amplified target sequences and probe sequences (located within the 23S ribosomal RNA gene rrl and the genes related to the toxicity of each bacterium) was detected in single‐probe or multiple‐probe assays, depending on the organism. The lower limits of detection (LLDs) for the probes ranged from 0.1 to 10 ng. Sensitivity was improved using lambda exonuclease to digest the noncomplementary target strand. All contributors in 33 binary, ternary, and quaternary mixtures in which all components were present in a 1:1 ratio were identified with an 80% success rate. Twenty‐eight binary mixtures in which the two components were combined in various ratios were further studied. All target sequences were detected, even when the minor component was overshadowed by a tenfold excess of the major component.     

Regional trade and foreign currency regimes among the former Soviet Republics

The paper examines the problems arising from the adoption of national currencies in former Soviet Republics, and advances proposals to avoid excessive trade and output contractions. The move towards national currencies in many republics — though politically unavoidable and economically efficient in the medium term — is seen as having disruptive effects on interrepublican trade in the short term, with heavy losses of incomes and employment, which add to the costs of market transition. Mutual convertibility among the new currencies could allow some of the negative consequences on trade and production to be overcome, while in the event of mutual currently inconvertibility the effects on interrepublic trade could be disastrous and only some form of payments agreement could reduce the magnitude of the contraction. An intermediate currency regime which could sustain the level of income and employment would be based on the use of the Russian rouble as a regional means of payment. Such an event, however, would require as a pre-condition the stabilization of the Russian currency.     

The transfer of touch DNA from hands to glass, fabric and wood

The transfer of DNA from hands to objects by holding or touching has been examined in the past. The main purpose of this study was to examine the variation in the amount of DNA transferred from hands to glass, fabric and wood. The study involved 300 volunteers (100 for glass, 100 for fabric and 100 for wood) 50% of which were male and 50% female. The volunteers held the material for 60 s. The DNA was recovered from the objects using a minitape lift, quantified using the Quantifiler kit assay, extracted using a ‘Qiagen^® QIAamp DNA mini kit’ and amplified using the AmpFlSTR^® SGM Plus™ Amplification Kit at 28 cycles. The results show that using ANOVA there was a significant difference (F = 8.2, p < 0.05) between the three object types in the amount of DNA recovered. In terms of DNA transfer and recovery, wood gave the best yield, followed by fabric and then glass. The likelihood of success of obtaining a profile indicative of the holder was approximately 9% for glass samples, 23% for fabric and 36% for wood. There was no significant difference between the amount of DNA transferred by male or female volunteers. In this study good shedder status, as defined by obtaining useful profiles of 6 or more alleles, is estimated at approximately 22% of the population. The phenomenon of secondary transfer was observed when mixed DNA profiles were obtained but the incidence was low at approximately 10% of the total number of samples. DNA profiles corresponding to more than one person were found on objects which had been touched by only one volunteer. Although secondary transfer is possible the profiles obtained from touched objects are more likely to be as a result of primary transfer rather than a secondary source.     

Drug Contamination of U.S. Paper Currency and Forensic Relevance of Canine Alert to Paper Currency: A Critical Review of the Scientific Literature

Several studies have reported on wide‐spread contamination of U.S. paper currency with cocaine and to a lesser extent other illicit drugs. Canines are trained and employed to search for and alert to drugs. Canine alert to currency has been used as evidence that currency has been directly involved in illicit drug trafficking to justify currency seizure and forfeiture. This assertion, particularly when the only evidence is based upon canine alert, has been challenged in the courts considering that most currency in circulation is contaminated with cocaine. Comprehensive review of the scientific literature establishes that (i) 67–100% of circulated U.S. currency is contaminated with cocaine ranging from a few nanograms to over one milligram/bill (ii) various biological and environmental parameters impact canine alert to drugs. It is concluded that canine alert to U.S. currency is not sufficiently reliable to determine that currency was directly used in an illicit drug transaction.     

An innovative transfer DNA experimental design and qPCR assay: Protocol and pilot study

Forensic “touch” DNA samples are low-quantity samples that are recovered from surfaces that have been touched by single or multiple individuals. These samples can include DNA from primary contributors who directly touched the surface, as well as secondary contributors whose DNA was transferred to the surface through an intermediary. It is difficult to determine the type of transfer, or how often and under what conditions DNA transfer occurs. In this paper, we present an innovative protocol that combines (1) a paired male and female transfer DNA experimental design in which the presence of male DNA indicates secondary transfer and (2) a cost-effective quantitative PCR (qPCR) assay of a sex-specific region in the Amelogenin gene to detect male and female DNA. We evaluate the ability of the Amelogenin qPCR assay to detect low concentrations of male and female DNA in mixed samples. We also test experimental DNA samples using our transfer DNA protocol to differentiate primary and secondary DNA transfer. Male DNA was detected in the majority of known mixed samples, even in samples with 4× more female DNA—this result demonstrates the ability to detect low concentrations of male DNA and the presence of secondary transfer DNA in our experimental design. Primary DNA transfer was detected in 100% of our experimental trials and secondary DNA transfer was detected in 37.5% of trials. Our innovative protocol mimics realistic case scenarios to establish rates of primary and secondary DNA transfer in an inexpensive and simplified manner.     

机制版假币票面上印刷疵点的检验

目的分析假币票样上的印刷疵点,为串并假币机制版印制点提供科学依据。方法通过图文扫描和图象处理技术,获取假币票面上的印刷疵点信息,研究梳理不同票面上一致的疵点组合,寻找其与印版的相关性,继而推导与印制者的相关性。结果找到可以表征相同胶片版或PS版的不同冠字号码假币票样上一致的印刷疵点。结论可以通过图文扫描和图象处理手段得到印刷疵点特征。     

China's central bank digital currency and its impacts on monetary policy and payment competition: Game changer or regulatory toolkit?

After carrying out some preparatory work for several years, China is likely to issue central bank digital currency (CBDC). Built upon the relevant experience and research in other countries, China has been carefully designing its own version of digital currency and issuance mechanism with a purpose of not disrupting financial intermediation. Nevertheless, it still leaves some residual issues unanswered, in particular, the narrow bank concern and application scenarios. While this article proposes to use interest rates as a policy solution to mitigate the narrow bank concern, the ultimate success of CBDC still depends on market competition. China's CBDC, while initially being used as a regulatory toolkit to compete with other digital currencies, has potential to become a game changer once used in a large scale.     

析外币债务判决中的Miliangos规则

法院地货币/违约日规则曾经被认为是英美法系外币债务判决中的基本原则,并且对很多大陆法系国家产生重要影响,这种状况一直持续到1975年英国上议院的Miliangos案才发生改变。Miliangos案以后的一系列案件将外币债务判决的Miliangos规则发展成为:法院可以用外国货币作出判决,或者按照实际支付日的汇率,折算成本国货币判决。在对Miliangos规则的确立、完善及其发展变化进行详尽阐述的基础上,可以对该规则进行有意义的评价和分析。     

Simulating transfer and persistence of a chemical marker powder for Lycopodium clavatum spores

In this research a chemical marker powder, based on Lycopodium clavatum spores, was studied to determine its transfer and persistence on a T-shirt. Such chemical marker powders are used to provide evidence that a person has handled a covertly marked object, such as a drug package. The powder was found to transfer readily between a marked item and the person handling it. The powder was found to persist on a T-shirt for up to 13 h; however, there was only a very small amount of powder remaining at this time. The rate of loss of the L. clavatum spores was found to follow a decay curve. The largest decrease in spores from the T-shirt was seen in the first 2 h after the marked item had been handled.     

Persistence of transferred fragrance on fabrics for forensic reconstruction applications

It has recently been established that volatile organic compounds (VOCs) successfully transfer between clothing even with a short contact of 10 s, highlighting the potential to use VOCs in forensic reconstruction scenarios, such as sexual assault cases. The mid and low volatility compounds transferred in greater amounts than high volatility compounds. This study presents empirical data addressing the persistence of transferred VOCs on clothing for the first time. A series of experiments were carried out to determine the persistence of VOCs on clothing for time periods of up 4 weeks, on natural and synthetic fibres, and at three different environmental temperatures. The data indicate that the highest VOC amounts are generally obtained for shorter persistence times of up to 1 d. Whilst high volatility compounds were not recovered in sufficient amounts to allow quantification, the four other transferred VOCs were successfully quantified for persistence times of up to 4 weeks. The persistence for mid-volatility compounds follows decay curve trends in line with those previously obtained for fibres, glass and pollen. When comparing the persistence of VOCs on a natural and a synthetic fibre, for a persistence time of 1 h, the transferred VOCs were retained on a natural fibre in higher amounts than on a synthetic fibre. However, for longer persistence times the concentration of VOCs was similar between the two fabrics. Lastly, lower environmental temperatures resulted in higher recoveries for most VOCs, especially for short persistence times. These findings demonstrate that optimal recovery of VOCs from clothing occurs when the fabric is kept at cooler temperatures and analysed soon after the fragrance transfer occurred, although VOC recovery was possible at higher temperatures and after longer persistence times. Given the transfer and persistence characteristics of VOCs from fragrance, there is potential for fragrance to be used as a form of trace in forensic reconstruction approaches.     

Analysis of the Effect of Cyclophosphamide and Methotrexate on Chrysomya megacephala (Diptera: Calliphoridae),

Forensic entomotoxicology investigates the effects of chemical substances in the development of scavenger insects and the reflection on estimating the minimum postmortem interval (PMI). To evaluate the impact of the chemotherapeutic drugs cyclophosphamide (CF) and methotrexate (MTX) on the postembryonic development of Chrysomya megacephala, controlled experiments were performed by rearing the larvae on spiked minced beef with different concentrations of these drugs. The results indicated that CF significantly decreased their developmental rate up to 28 h but had no significant effect on larval and adult sizes, survival rate, and sex ratio, whereas MTX decreased larval and adult sizes, survival rate, and there was a deviation in the expected sex ratio toward females in MTX‐exposed larvae but had no significant impact on developmental rate. These negative interference factors should be considered in cases of suspected death of people that have undergone chemotherapy.     

The Recovery and Persistence of Salivary DNA on Human Skin

Abstract: Salivary DNA is encountered in many crimes, such as sexual assaults and murders. In this study, saliva from three male donors was deposited on the skin of three female recipients. The amount of male salivary DNA remaining on the female skin was measured over a 96‐h period using the Quantifiler? Y Human Male DNA Quantification Kit. In eight of the nine experiments, a full male DNA profile matching the donor was obtained even after 96 h. In addition, the study showed that the concentration of salivary DNA varied from donor to donor and from day to day. The efficiency of two recovery methods, wet and dry swabbing and minitaping, was compared. The results indicate the tapelift method gave higher DNA recovery. This study also examined the secondary transfer of salivary DNA from skin to fabrics. Cotton and polyester give higher DNA transfer than leather.     

Pitfalls in the Interpretation of Traumatic Socioethnic Practices

The purpose of this case study was to raise awareness among forensic pathologists and medicolegal death investigators regarding two unique socioethnic practices and regional customs that have significant forensic implications. We present two cases involving coining (gua sha) and bloodletting (sapi) that represent two forms of traditional customs that involve the use of blunt force and sharp force trauma, respectively. In coining, the skin lesions are produced as a result of dermabrasion with oils and oval objects such as coin. In sapi, multiple superficial linear scrapes are made in the skin as part of a bloodletting ceremony. The identification of these lesions will prevent the interpretation of them as non‐voluntary‐inflicted trauma.     

Identification of some factors influencing soil transfer on shoes

In criminal activities, soil can be transferred from a crime scene to items linked with a perpetrator; for example, shoes, cars or tools. Several parameters will influence the quantity of soil transferred in a given scenario. The knowledge of the most influential factors can help the expert to assess the evidence using a logical approach at the activity level or to predict the amount of soil that can be expected in a given scenario. The influence of five chosen parameters, namely the shoe profile, shoe size, walker's weight, soil type and soil humidity were assessed using Design of Experiment (DOE) in order to understand their influence on soil quantity transferred on shoes.The Faced Central Composite Design (FCCD) using a quadratic model was found to be highly significant, thus they could be adequately used to model and to interpret the amount of soil recovered from one shoe.These designs demonstrate that the characteristics of the donor (soil type and soil humidity), as well as a combination of these two factors have a very significant impact on the soil transfer. The characteristics of the receptor (shoe profile, shoe size and walker's weight) also have an impact on the transfer but to a lesser extent.Globally, this research provides valuable information for the forensic scientist both in investigative mode: evaluation of the soil quantity possibly transferred on shoes, and in the evaluative steps: is the quantity of soil found on the suspect shoes in accordance to the proposition/scenario given by the prosecution and the defence?     

Forensic Identification of Indian Snakeroot (Rauvolfia serpentina Benth. ex Kurz) Using DNA Barcoding

Indian snakeroot (Rauvolfia serpentina) is a valuable forest product, root extracts of which are used as an antihypertensive drug. Increasing demand led to overharvesting in the wild. Control of international trade is hampered by the inability to identify root samples to the species level. We therefore evaluated the potential of molecular identification by searching for species‐specific DNA polymorphisms. We found two species‐specific indels in the rps16 intron region for R. serpentina. Our DNA barcoding method was tested for its specificity, reproducibility, sensitivity and stability. We included samples of various tissues and ages, which had been treated differently for preservation. DNA extractions were tested in a range of amplification settings and dilutions. Species‐specific rps16 intron sequences were obtained from 79 herbarium accessions and one confiscated root, encompassing 39 different species. Our results demonstrate that molecular analysis provides new perspectives for forensic identification of Indian snakeroot.     

Characteristics of Forensic Imaging Performance—An Analysis of Forensic Imaging Bottlenecks

Disk imaging involves copying all of the data from a source disk drive to a target. Typically, the target for the copy is another disk drive. Forensic processes developed years ago do not appear to be adequate for current storage technology. For example, with disk drive capacities now exceeding 1 Terabyte, a typical disk imaging can take over 8 hours at typical rates. With disk drive capacities increasing, forensic copying is expected to take even longer. Along with increase in disk capacity, the industry has also seen an increase in data transfer rates. In many cases, forensic imaging is taking longer than necessary. To identify the bottlenecks, an examination of different methods used to transfer data from a source disk was performed. Factors considered were differing disk access technologies. One finding is that the USB disk access technology (version 2.0 and earlier) is a significant bottleneck for data transfer rates, especially when the USB device is a write‐blocker. Other factors that contribute to the efficiency of a forensic copy are the file system used to write a forensic image and the data transfer size used when reading from a disk drive. Optimal parameters for performing a forensic acquisition from a disk drive are identified.