bluuebunny/crossref_metadata_2025 huggingface dataset:
Separable lower triangular bilinear model
Authors: Wang Hai-Bin , Wei Bo-Cheng
Published: May 2004

The aim of this paper is to analyze the probabilistic structure for a rather general class of bilinear models systematically. First, the sufficient and necessary conditions for stationarity are given with a concise expression. Then both the autocovariance function and the spectral density function are obtained. The Yule–Walker-type difference equations for autocovariances are derived by means of the spectral density function. Concerning the second-order probabilistic structure, the model is similar to an ARMA model. The third-order probabilistic structure for the model is discussed and a group of Yule–Walker-type difference equations for third-order cumulants are discovered.
Minimal martingale measures for jump diffusion processes
Authors: Arai Takuji
Published: May 2004

We consider an incomplete market model whose stock price fluctuation is given by a jump diffusion process. For this model, we calculate the density process of the minimal martingale measure. Also, we state the relation to a locally risk-minimizing strategy.
Branching processes in near-critical random environments
Authors: Jagers Peter , Klebaner Fima
Published: May 2004

Branching processes are studied in random environments that are influenced by the population size and approach criticality as the population gets large. Results are applied to the polymerase chain reaction (PCR), which is empirically known to exhibit first exponential and then linear growth of molecule numbers.
A prediction problem of the branching random walk
Authors: Révész P.
Published: May 2004

The location of the ‘favourite’ point at time T (T = 1, 2,…) of a supercritical branching random walk at ℤd is investigated.
Box–Cox transformations and heavy-tailed distributions
Authors: Teugels Jef L. , Vanroelen Giovanni
Published: May 2004

It is a stylized fact that estimators in extreme-value theory suffer from serious bias. Moreover, graphical representations of extremal data often show erratic behaviour. In the statistical literature it is advised to use a Box–Cox transformation in order to make data more suitable for statistical analysis. We provide some of the theoretical background to see the effect of such transformations and to investigate under what circumstances they might be helpful.
Summability methods and negatively associated random variables
Authors: Bingham N. H. , Nili Sani H. R.
Published: May 2004

The paper studies convergence of sequences of negatively associated random variables under various summability methods. The results extend previously known results for independence and complement known results forϕ-mixing.
Critical growth of a semi-linear process
Authors: Molchanov Ilya , Shcherbakov Vadim , Zuyev Sergei
Published: May 2004

This paper is motivated by the modelling of leaching of bacteria through soil. A semi-linear process Xt− may be used to describe the soil-drying process between rain showers. This is a backward recurrence time process that corresponds to the renewal process of instances of rain. If a bacterium moves according to another process h, then the fact that h(t) stays above Xt− means that the bacterium never hits a dry patch of soil and so survives. We describe a critical behaviour of h that separates the cases when survival is possible with a positive probability from the cases when this probability vanishes. An explicit formula for the survival probability is obtained in case h is linear and rain showers follow a Poisson process.
Comparison of multivariate risks and positive dependence
Authors: Rüschendorf Ludger
Published: May 2004

In this paper we extend some recent results on the comparison of multivariate risk vectors with respect to supermodular and related orderings. We introduce a dependence notion called the ‘weakly conditional increasing in sequence order’ that allows us to conclude that ‘more dependent’ vectors in this ordering are also comparable with respect to the supermodular ordering. At the same time, this ordering allows us to compare two risks with respect to the directionally convex order if the marginals increase convexly. We further state comparison criteria with respect to the directionally convex order for some classes of risk vectors which are modelled by functional influence factors. Finally, we discuss Fréchet bounds with respect to Δ-monotone functions when multivariate marginals are given. It turns out that, in the case of multivariate marginals, comonotone vectors no longer yield necessarily the largest risks but, in some cases, may even be vectors which minimize risk.
Generalized integrated telegraph processes and the distribution of related stopping times
Authors: Zacks S.
Published: May 2004

Let {X(t), V(t), t ≥ 0} be a telegraph process, with V(0+) = 1. The distribution of X(t) is derived for the general case of an alternating renewal process, describing the length of time a particle is moving to the right or to the left. The distributions of the first-crossing times of given levels a and −a are studied for M/G and for G/M processes.
The compound Poisson immigration process subject to binomial catastrophes
Authors: Economou Antonis
Published: May 2004

Recently, several authors have studied the transient and the equilibrium behaviour of stochastic population processes with total catastrophes. These models are reasonable for modelling populations that are exposed to extreme disastrous phenomena. However, under mild disastrous conditions, the appropriate model is a stochastic process subject to binomial catastrophes. In the present paper we consider a special such model in which a population evolves according to a compound Poisson process and catastrophes occur according to a renewal process. Every individual of the population survives after a catastrophe with probability p, independently of anything else, i.e. the population size is reduced according to a binomial distribution. We study the equilibrium distribution of this process and we derive an algorithmic procedure for its approximate computation. Bounds on the error of this approximation are also included.
Decomposition property in a discrete-time queue with multiple input streams and service interruptions
Authors: Ishizaki Fumio
Published: May 2004

This paper studies a discrete-time single-server queue with two independent inputs and service interruptions. One of the inputs to the queue is an independent and identically distributed process. The other is a much more general process and it is not required to be Markov nor is it required to be stationary. The service interruption process is also general and it is not required to be Markov or to be stationary. This paper shows that a stochastic decomposition property for the virtual waiting-time process holds in the discrete-time single-server queue with service interruptions. To the best of the author's knowledge, no stochastic decomposition results for virtual waiting-time processes in non-work-conserving queues, such as queues with service interruptions, have been obtained before and only work-conserving queues have been studied in the literature.
On Markov-dependent parking problems
Authors: Yang Jiing-Ru , Hsiau Shoou-Ren
Published: May 2004

We drive a car along a street towards our destination and look for an available parking place without turning around. Each parking place is associated with a loss which decreases with the distance of the parking place from our destination. Assume that the states (empty or filled) of the parking places form a Markov chain. We want to find an optimal parking strategy to minimize the expected loss. A curious example is constructed and two sufficient conditions for the existence of the threshold-type optimal parking strategy are given.
Geometric L2 and L1 convergence are equivalent for reversible Markov chains
Authors: Roberts Gareth O. , Tweedie Richard L.
Published: May 2004

The paper proves the statement of the title, and shows that it has useful applications in evaluating the convergence of queueing models and Gibbs samplers with deterministic and random scans.
Similar Markov chains
Authors: Pollett P. K.
Published: May 2004

Lenin et al. (2000) recently introduced the idea of similarity in the context of birth-death processes. This paper examines the extent to which their results can be extended to arbitrary Markov chains. It is proved that, under a variety of conditions, similar chains are strongly similar in a sense which is described, and it is shown that minimal chains are strongly similar if and only if the corresponding transition-rate matrices are strongly similar. A general framework is given for constructing families of strongly similar chains; it permits the construction of all such chains in the irreducible case.
Point process convergence of stochastic volatility processes with application to sample autocorrelation
Authors: Davis Richard A. , Mikosch Thomas
Published: May 2004

The paper considers one of the standard processes for modeling returns in finance, the stochastic volatility process with regularly varying innovations. The aim of the paper is to show how point process techniques can be used to derive the asymptotic behavior of the sample autocorrelation function of this process with heavy-tailed marginal distributions. Unlike other non-linear models used in finance, such as GARCH and bilinear models, sample autocorrelations of a stochastic volatility process have attractive asymptotic properties. Specifically, in the infinite variance case, the sample autocorrelation function converges to zero in probability at a rate that is faster the heavier the tails of the marginal distribution. This behavior is analogous to the asymptotic behavior of the sample autocorrelations of independent identically distributed random variables.
Relative quiescence within the Jiashi swarm in Xinjiang, China: an application of the ETAS point process model
Authors: Ma Li , Zhuang Jiancang
Published: May 2004

This paper uses the epidemic-type aftershock sequence (ETAS) point process model to study certain seismicity features of the Jiashi swarm of certain earthquakes, investigating in particular whether there is relative quiescence prior to the quite big events within the Jiashi sequence. The seven earthquake sequences studied occurred in the region of Jiashi, south of Tianshan Mountain, Xinjiang, China. The particular ETAS model that is developed is consistent with the reality of seismic activity. The various features of Jiashi swarm activity can be described as focusing in different stages. There is obvious precursory quiescence prior to most big events withMs≥ 6.0 within the Jiashi swarm. Thus, checking for relative quiescence can be use for earthquake prediction.
Point process modelling of reservoir-induced seismicity
Authors: Imoto Masajiro
Published: May 2004

A point process procedure can be used to study reservoir-induced seismicity (RIS), in which the intensity function representing earthquake hazard is a combination of three terms: a constant background term, an ETAS (epidemic-type aftershock sequence) term for aftershocks, and a time function derived from observation of water levels of a reservoir. This paper presents the results of such a study of the seismicity in the vicinity of the Tarbela reservoir in Pakistan. Making allowance for changes in detection capability and the background seismicity related to tectonic activity, earthquakes of magnitude ≥ 2.0, occurring between May 1978 and January 1982 and whose epicentres were within 100 km of the reservoir, were used in this analysis. Several different intensities were compared via their Akaike information criterion (AIC) values relative to those of a Poisson process. The results demonstrate that the seismicity within 20 km of the reservoir correlates with water levels of the reservoir, namely, active periods occur about 250 days after the appearance of low water levels. This suggests that unloading the reservoir activates the seismicity beneath it. Seasonal variations of the seismicity in an area up to 100 km from the reservoir were also found, but these could not be adequately interpreted by an appropriate RIS mechanism.
PAR-3 is required for epithelial cell polarity in the distal spermatheca of C. elegans
Authors: Aono Shinya , Legouis Renaud , Hoose Wendy A. , Kemphues Kenneth J.
Published: May 2004

PAR-3 is localized asymmetrically in epithelial cells in a variety of animals from Caenorhabditis elegans to mammals. Although C. elegans PAR-3 is known to act in early blastomeres to polarize the embryo, a role for PAR-3 in epithelial cells of C. elegans has not been established. Using RNA interference to deplete PAR-3 in developing larvae, we discovered a requirement for PAR-3 in spermathecal development. Spermathecal precursor cells are born during larval development and differentiate into an epithelium that forms a tube for the storage of sperm. Eggs must enter the spermatheca to complete ovulation. PAR-3-depleted worms exhibit defects in ovulation. Consistent with this phenotype, PAR-3 is transiently expressed and localized asymmetrically in the developing somatic gonad, including the spermathecal precursor cells of L4 larvae. We found that the defect in ovulation can be partially suppressed by a mutation in IPP-5, an inositol polyphosphate 5-phosphatase, indicating that one effect of PAR-3 depletion is disruption of signaling between oocyte and spermatheca. Microscopy revealed that the distribution of AJM-1, an apical junction marker,and apical microfilaments are severely affected in the distal spermatheca of PAR-3-depleted worms. We propose that PAR-3 activity is required for the proper polarization of spermathecal cells and that defective ovulation results from defective distal spermathecal development.
αvβ3 integrin-dependent endothelial cell dynamics in vivo
Authors: Rupp Paul A. , Czirók András , Little Charles D.
Published: May 2004

A major challenge confronting developmental cell biologists is to understand how individual cell behaviors lead to global tissue organization. Taking advantage of an endothelial cell-specific marker and scanning time-lapse microscopy, we have examined the formation of the primary vascular pattern during avian vasculogenesis. Five types of distinguishable endothelial cell motion are observed during formation of a vascular plexus: (1) global tissue deformations that passively convect endothelial cells; (2) vascular drift, a sheet-like medial translocation of the entire vascular plexus; (3)structural rearrangements, such as vascular fusion; (4) individual cell migration along existing endothelial structures; and (5) cell process extension into avascular areas, resulting in new links within the plexus. The last four types of motion are quantified and found to be reduced in the presence of an αvβ3 integrin inhibitor. These dynamic cell motility data result in new hypotheses regarding primordial endothelial cell behavior during embryonic vasculogenesis.
Two classic cadherin-related molecules with no cadherin extracellular repeats in the cephalochordate amphioxus: distinct adhesive specificities and possible involvement in the development of multicell-layered structures
Authors: Oda Hiroki , Akiyama-Oda Yasuko , Zhang Shicui
Published: May 2004

We previously reported the existence of Bb-cadherin, a molecule related to classic cadherin, in the cephalochordate amphioxus (Branchiostoma belcheri). The structure of Bb-cadherin is unique in that it lacks the cadherin extracellular repeats, although its cytoplasmic domain shows close similarities to those of typical classic cadherins. The extracellular region of Bb-cadherin consists of laminin globular domains and a cysteine-rich EGF-like domain that are similar to domains in nonchordate classic cadherins. In this study, we identified a second amphioxus cadherin. It was designated Bb2-cadherin (Bb2C) while the previously reported cadherin has been renamed Bb1-cadherin (Bb1C). Bb2C is very similar to Bb1C in its overall structure and amino acid sequence. Genomic BLAST searches and phylogenetic analyses suggested that these two amphioxus genes have been generated through a gene duplication that occurred after separation of the cephalochordates from the other animals. They also bear distinct adhesive specificities. Immunohistochemical analyses showed that Bb1C and Bb2C, together with β-catenin, appear to function as adherens junction constituents in the epithelia of different germ layers of the amphioxus embryo. Differential expression of the two cadherins was also observed in the developing, multicell-layered notochord. These observations suggest that, despite their unique structures, the functions and developmental roles of Bb1C and Bb2C are comparable to those of the classic cadherins characterized to date in other animal groups, such as the vertebrate E- and N-cadherins and the Drosophila DE- and DN-cadherins. The possible involvement of Bb1C and Bb2C in the development of multicell-layered structures characteristic of the cephalochordate body plan is presented.
Role of the cytoskeleton in signaling networks
Authors: Forgacs Gabor , Yook Soon Hyung , Janmey Paul A. , Jeong Hawoong , Burd Christopher G.
Published: May 2004

Intracellular signal transduction occurs through cascades of reactions involving dozens of proteins that transmit signals from the cell surface, through a crowded cellular environment filled with organelles and a filamentous cytoskeleton, to specific targets. Numerous signaling molecules are immobilized or transiently bound to the cytoskeleton, yet most models for signaling pathways have no specific role for this mesh, which is often presumed to function primarily as a scaffold that determines cell mechanics but not information flow. We combined analytical tools with several recently established large-scale protein-protein interaction maps for Saccharomyces cerevisiae to quantitatively address the role of the cytoskeleton in intracellular signaling. The results demonstrate that the network of signaling proteins is intimately linked to the cytoskeleton, suggesting that this interconnected filamentous structure plays a crucial and distinct functional role in signal transduction.
Response to Comments on Howard (2004)
Authors: Howard Ronald A.
Published: May 2004

These remarks respond to the comments offered by four colleagues on my paper “Speaking of Decisions: Precise Decision Language” (Howard 2004). The response gives me the opportunity to clarify and expand on the paper and to note different views. In particular, I further discuss random variable, distinction, expected value, option, utility as a measure of happiness or satisfaction, subjective probability, the necessity of a value measure for computing the value of clairvoyance, decision analysis as a normative discipline, and the inability of the clairvoyant to provide probabilities. I conclude with a concept map for the language and a table showing where the terms are most useful in conversations with students and clients.
Bupropion for Treatment of Interferon-Induced Depression
Authors: Malek-Ahmadi Parviz , Ghandour Elias
Published: May 2004

OBJECTIVE:

To report the effect of bupropion in a patient with interferon (IFN)-induced depression and review the use of antidepressants for treatment of depressive symptoms associated with IFN therapy.

CASE SUMMARY:

A 43-year-old white woman with chronic hepatitis C and severe IFN-induced depression was treated with sustained-release bupropion initiated at 150 mg/day for 7 days and 100 mg twice daily thereafter. The dosage was increased again, to 350 mg/day when depressive symptoms recurred. While receiving that dose and continuing IFN treatment, she reported significant improvement in her depressive symptoms without experiencing any adverse effects.

DISCUSSION:

There is limited evidence suggesting that IFNs decrease central serotonergic transmission. There are several published reports on the use of selective serotonin-reuptake inhibitors for the treatment of IFN-induced depression. However, controlled studies are needed to assess the efficacy of serotonergic and noradrenergic antidepressants in IFN-treated patients with depressive symptoms.

CONCLUSIONS:

Sustained-release bupropion might be of potential benefit in patients with interferon-induced depression.
Metformin for Prevention of Type 2 Diabetes
Authors: Hess Aleda M , Sullivan Donald L
Published: May 2004

OBJECTIVE:

To evaluate evidence from the medical literature that metformin is effective in preventing type 2 diabetes.

DATA SOURCES:

Primary literature was accessed via a MEDLINE search (1966—December 2003) using the terms metformin, type 2 diabetes, and prevention.

DATA SYNTHESIS:

Two studies evaluated metformin's potential to prevent type 2 diabetes, finding that metformin maintained or reduced fasting blood glucose in non-diabetics. Recently, a large study by the Diabetes Prevention Program showed that metformin may reduce the incidence of diabetes. Researchers compared lifestyle changes, metformin therapy, and placebo groups. They found that both lifestyle changes (58%) and metformin therapy (31%) significantly reduced the occurrence of type 2 diabetes versus placebo.

CONCLUSIONS:

These studies provide evidence that metformin may reduce the occurrence of type 2 diabetes. Because long-term efficacy has not been determined, further studies are needed.
Risk Factors for Community-Acquired Ciprofloxacin-Resistant Escherichia Coli Urinary Tract Infection
Authors: Killgore Karla M , March Kristi L , Guglielmo B Joseph
Published: May 2004

BACKGROUND:

Fluoroquinolones are recommended for the empiric treatment of urinary tract infection (UTI) in communities in which uropathogen resistance to trimethoprim/sulfamethoxazole (TMP/SMX) is ≥10% to 20%. However, recent studies also have demonstrated an increase in the isolation of fluoroquinolone-resistant Escherichia coli. Identification of outpatients at increased risk for fluoroquinolone resistance would improve the selection of empiric treatment.

OBJECTIVE:

To identify risk factors for community-acquired UTIs due to ciprofloxacin-resistant E. coli (CREC).

METHODS:

All medical records from the University of California at San Francisco Medical Center from January to December 2001 were retrospectively reviewed to identify patients with community-acquired UTI due to CREC. Patients with community-acquired UTI due to ciprofloxacin-susceptible E. coli presenting during the same time period were randomly selected as the study group in a 1:2 ratio of case to controls.

RESULTS:

Independent risk factors for CREC included recurrent UTI (OR 8.13) and prior exposure to fluoroquinolones (OR 30.35).

CONCLUSIONS:

Fluoroquinolones continue to be appropriate empiric treatment in most patients with uncomplicated UTI. Nitrofurantoin or a cephalosporin may be better choices in patients with recurrent lower UTI and/or previous fluoroquinolone use.
A test of integration of the activation hypothesis and the diathesis‐stress component of the hopelessness theory of depression
Authors: Abela John R. Z. , Brozina Karen , Seligman Martin E. P.
Published: May 2004

Objectives: This prospective study tested the integration of the diathesis‐stress component of the hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) and Persons and Miranda's (1992) activation hypothesis (i.e. depressogenic inferential styles are typically latent cognitive processes that must be primed in order to be accurately assessed).

Design: In order to test the diathesis‐stress component of the hopelessness theory, we used a short‐term longitudinal design. In order to test the activation hypothesis, inferential styles were assessed both before and after a negative cognitive priming questionnaire.

Methods: A group of 165 university students completed measures of inferential styles about the self, consequences, and causes before and after completing a negative cognitive priming questionnaire (Time 1). Participants also completed measures of depressive symptoms prior to completing the cognitive priming questionnaire and 5 weeks later (Time 2). Finally, negative events occurring between Time 1 and Time 2 were assessed.

Results: Contrary to the diathesis‐stress component of the hopelessness theory, none of the unprimed inferential styles interacted with negative events to predict increases in depressive symptoms. In line with the integration of the hopelessness theory and the activation hypothesis, however, each of the primed inferential styles interacted with negative events to predict increases in depressive symptoms even after controlling for the proportion of variance in depressive symptoms accounted for by the unprimed inferential style stress interactions.

Conclusion: Individuals with depressogenic inferential styles are likely to show increases in depressive symptoms following the occurrence of negative events. At the same time, these depressogenic inferential styles are typically latent cognitive processes that must be primed in order to be accurately assessed.
Vitamin D Receptor mRNA Measured in Leukocytes with the TaqMan Fluorogenic Detection System: Effect of Calcitriol Administration
Authors: Soldati Laura , Adamo Donatella , Bianchin Cristiana , Arcidiacono Teresa , Terranegra Annalisa , Bianchi Maria Luisa , Mora Stefano , Cusi Daniele , Vezzoli Giuseppe
Published: May 2004

Background: The aim of the present study was to investigate the interactions between the circulating concentrations of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and the mRNA concentration of its specific nuclear receptor in human leukocytes.

Methods: We measured vitamin D receptor (VDR) mRNA extracted from leukocytes by use of TaqMan fluorescence analysis applied to the reverse transcription-PCR (RT-PCR) technique in 16 volunteers before and after calcitriol administration. VDR mRNA was also measured in leukocytes from calcium-stone-formers (37 hypercalciuric and 34 normocalciuric patients). The relationship between VDR mRNA concentrations and genetic VDR polymorphisms was analyzed in these patients.

Results: Imprecision (CV) of RT-PCR was 1.3% within assay (n = 10) and 1.7% between assays (n = 4). Oral 1,25(OH)2D3 increased mean (SE) serum 1,25(OH)2D3 1.6 (0.3)-fold and VDR mRNA 1.6 (0.1)-fold 8 h after administration. The maximum VDR mRNA was reached 3.6 (1.3) h after 1,25(OH)2D3 ingestion. No differences in leukocyte VDR mRNA concentrations were found between normocalciuric and hypercalciuric stone-formers in the absence of stimulation. Finally, no association was found between VDR mRNA concentrations and genetic VDR polymorphisms in stone-formers.

Conclusions: The TaqMan RT-PCR assay is a rapid and accurate method to measure VDR mRNA, and leukocytes are a useful model to study VDR and 1,25(OH)2D3 interactions. In humans, VDR mRNA is increased by agonist 1,25(OH)2D3, a finding resembling previously reported results obtained in cellular and animal models.
Effect of Leachate Composition on the Adsorption Properties of Two Soils
Authors: Du YJ , Hayashi S
Published: May 2004

The experimental results show that the composition of the contaminant leachate affects the adsorption behavior for the soil tested. However, this conclusion is based on the assumption that the soil adsorption isotherm is linear. To investigate this effect when the adsorption isotherm is nonlinear, a series of batch tests were conducted with a single-salt solution (KCl, CaCl2, and NaCl solution, respectively) and multi-salt solution (aqueous miscible solution containing KCl, CaCl2, and NaCl) for the selected two soils from Japan. A comparison of the test results between these two conditions indicated that for a specified cation of interest, soils adsorbed larger amounts of cations in the case of the single-salt condition relative to the multisalt condition. The Freundlich equation was adopted to fit the experimental data, and the model parameters are presented. The relative cation adsorption of soils is provided and the controlling factors are discussed.
Measuring Soil Electrical Resistivity Using a Resistivity Box and a Resistivity Probe
Authors: Sreedeep S , Reshma AC , Singh DN
Published: May 2004

This technical note deals with the fabrication and details of an electrical resistivity box and an electrical resistivity probe, for estimating soil electrical resistivity. Calibration of these setups has been done with the standard KCl and NaCl solutions. Using this calibration, electrical resistivity of a locally available silty soil and commercially available white clay has been determined. Further, efforts have been made to develop relationships between the electrical resistivity of these soils and their saturation. Results available in the literature have been used to validate these relationships.
The Louisiana Plane Strain Apparatus for Soil Testing
Authors: Alshibli KA , Godbold DL , Hoffman K
Published: May 2004

The mechanical description of a new plane strain (biaxial) apparatus for soil testing is presented. The design took into consideration flexibility in accomodating different specimen sizes, easy assembly procedure, and well-controlled boundary conditions. The apparatus is well instrumented with load, displacement, and pressure sensors and has the capabilities to capture localization and shear band development. A comparison between two experiments that were conducted on F-75 Ottawa sand is presented and the effect of inhibiting lateral movement of bottom end platen is presented and discussed. It has been found that restraining lateral movement of bottom end platen has resulted in higher peak and residual load values.
Analysis of Dyes in Illicit Pills (Amphetamine and Derivatives)
Authors: Goldmann T , Taroni F , Margot P
Published: May 2004

The determination of dyes present in illicit pills is shown to be useful and easy-to-get information in strategic and tactical drug intelligence. An analytical strategy including solid-phase extraction (SPE) thin-layer chromatography (TLC) and capillary zone electrophoresis equipped with a diode array detector (CZE-DAD) was developed to identify and quantify 14 hydrosoluble, acidic, synthetic food dyes allowed in the European Community. Indeed, these may be the most susceptible dyes to be found in illicit pills through their availability and easiness of use. The results show (1) that this analytical method is well adapted to small samples such as illicit pills, (2) that most dyes actually found belong to hydrosoluble, acidic, synthetic food dyes allowed in the European Community, and (3) that this evidence turns out to be important in drug intelligence and may be assessed into a Bayesian framework.
A Preliminary Investigation of the Stages of Adipocere Formation
Authors: Forbes SL , Stuart BH , Dadour IR , Dent BB
Published: May 2004

Adipocere is a postmortem decomposition product which forms from a body's adipose tissue. This study aimed to chemically demonstrate the process of conversion from adipose tissue to adipocere. Samples of adipocere were collected from pig cadavers that were allowed to decompose for varying intervals. Samples of soil were collected from beneath the cadavers and analyzed to determine the leaching effect of adipocere. Gas chromatography/mass spectrometry (GC/MS) was used to quantify the fatty acid composition of pig adipocere. Fourier transform infrared spectroscopy (FTIR) was used as a confirmatory test and to identify other components such as triglycerides and calcium salts of fatty acids. The study demonstrates the process of adipocere formation and the stages of formation through which the process passes using chemical techniques.
SWGDAM Developmental Validation of a 19-Locus Y-STR System for Forensic Casework
Authors: Daniels DL , Hall AM , Ballantyne J
Published: May 2004

A Scientific Working Group on DNA Analysis Methods (SWGDAM) developmental validation study was carried out on two Y- STR multiplex systems (MPI and MPII) that collectively permit the co-amplification of 19 Y-STR markers, including DYS393, DYS392, DYS391, DYS389I, DYS389II, Y-GATA-A7.2 (DYS461), DYS438, DYS385a and DYS385b (MPI); DYS425, DYS388, DYS390, DYS439, DYS434, DYS437, Y-GATA-C.4, Y-GATA-A7.1 (DYS460), Y-GATA-H.4, and DYS19 (MPII). Performance checks subsequent to PCR parameter optimization indicated that MPI and MPII were suitably reproducible, precise and accurate for forensic use. The sensitivity of the systems was such that a full 19-locus Y-STR profile was obtainable with 150–200 pg of male DNA, and some loci were detectable even with as little as 20–30 pg of input DNA. Primate specificity was demonstrated by the lack of cross-reactivity with a variety of commonly encountered bacterial and animal species, with the single exception of a monomorphic canine product that was outside of the size range of human alleles from any of the 19 loci. Not surprisingly, cross-reactivity was observed with a number of male and female nonhuman primates. Environmentally compromised samples produced full or partial Y-STR profiles. For example, a semen stain exposed to the outdoor elements for six months still gave a 13-locus Y-STR profile. Although a limited number of female DNA artifacts were observed in mixed stains in which the male DNA comprised 1/300 of the total, the full 19-locus male profile was easily discernible. Even at a 1500-to-2000-fold dilution of male DNA with female DNA partial Y-STR profiles were obtained. Furthermore, the potential utility of MPI and MPII for forensic casework is exemplified by their ability to dissect out the male haplotype in a variety of case-type samples, including, inter alia, post-coital vaginal swabs, admixed male and female bloodstains, the nonsperm fraction from a differentially extracted semen stain, and determination of the number of male donors in mixed semen stains.
A Method for Impregnating Nylon Transfer Membranes with Leucocrystal Violet for Enhancing and Lifting Bloody Impressions
Authors: Michaud AL , Brun-Conti L
Published: May 2004

The objective of this research project was to demonstrate a quick and easy method for impregnating nylon transfer membranes with leucocrystal violet (LCV) for the purpose of lifting and enhancing impressions made in blood. A stamp that would simulate fine detail found in fingerprints or footwear was used to create impressions on a variety of substrates. Four different LCV formulations were tested to determine the effectiveness of the prepared membranes in lifting and enhancing the impressions. Further investigation involved the feasibility of using the LCV membranes in the field by studying the shelf life and storage of the impregnated membranes and the longevity of the lifted impressions. One of the formulations studied demonstrated superior lifting and enhancing capabilities, as well as a prolonged shelf life and a resilience of the lifted impressions, thus proving LCV to be an extremely valuable technique.
Sex Differences and Aging of the Vertebral Column
Authors: Snodgrass JJ
Published: May 2004

Morphological changes in the adult human skeleton have been recognized as useful for estimating the age at death. In the vertebral column, the development of osteophytes has been shown to be a general indicator of age, although substantial variation has been documented. The technique used for estimating age from osteophyte development is based exclusively on males and it is unknown whether patterns of osteophyte development are comparable between the sexes. This study examines sex differences in osteophyte development in the thoracic and lumbar regions of 384 individuals from the Terry Collection. Males and females in this sample show remarkably similar patterns of age-related changes in osteophyte development; however, females show greater variability in osteophyte stage for a given age. This was confirmed with age-matching a subsample of 128 individuals. Therefore, slightly larger confidence intervals should be used when assessing age from the vertebral column in females.
A Second Survey of High Explosives Traces in Public Places
Authors: Cullum HE , McGavigan C , Uttley CZ , Stroud MAM , Warren DC
Published: May 2004

This survey was carried out as a follow-up to a 1994 survey carried out by this laboratory (1) in order to determine the background levels of explosives traces in public places. The first survey concentrated on transport areas and police stations in and around London. This second study examines levels in four of the United Kingdom's major cities: Birmingham, Cardiff, Glasgow, and Manchester. Samples were taken at various transport sites and from hotels, private houses, private vehicles, and clothing. The survey showed that traces of the high explosives nitroglycerine (NG), trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and cyclotrimethylene trinitramine (RDX) are rare within the general public environment. Only one low-level trace of RDX was detected. NG, possibly associated with the use of firearms, was detected at low levels in two samples and 2, 4-DNT was detected in a separate sample. No PETN was detected in any of the samples. The results of the survey indicate that it is unlikely that persons visiting public areas could become significantly contaminated with explosives. The analytical procedures employed would also have detected ethylene glycol dinitrate (EGDN) if present at levels greater than 2 ng, nitrobenzene (NB) if present at levels greater than 50 ng, mononitrotoluenes if present at levels greater than 50 ng, and the other common isomers of dinitrotoluene if these had been present at levels in excess of 10 ng. None of these were detected. The relatively high volatility of EGDN, NB, and the mononitrotoluenes would, however, cause traces of these compounds to disperse rapidly. A proportion of the samples (approximately 7%) were analyzed for the presence of HMX. No HMX was detected.
Thermogravimetric Analysis as a Polymer Identification Technique in Forensic Applications
Authors: Ihms EC , Brinkman D
Published: May 2004

This paper investigates the potential of thermogravimetric analysis (TGA) as a tool for determination of different species of polymers. Materials analyzed include polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polystyrene, polypropylene, nitriles, and nylon. Analyses showed excellent discriminating results even when samples were contaminated with silicates, organics, moisture, and char. The techniques developed were designed with a forensic-type analysis in mind, such as analysis of blast fragments and arson debris. Techniques were developed that gave satisfactory results even when sample sizes were less than five milligrams.
The Use of an Electrostatic Detection Device to Identify Individual and Class Characteristics on Documents Produced by Printers and Copiers—A Preliminary Study
Authors: LaPorte GM
Published: May 2004

The market is inundated with inkjet printers, laser printers, and photocopiers, which are often used in criminal activities. Many of these office machines are built by various manufacturers, hence they are constructed with different hardware designs (e.g. “rolling” and “grabbing” mechanisms) that have changed over the years due to technological advances. Examinations of printed documents that involve the chemical analysis of ink colorants and the identification of physical machine defects such as trash marks are essential for the forensic examiner, but new techniques are needed to more closely identify a machine model or group of models. An electrostatic detection device (EDD) provides forensic examiners with a nondestructive method to examine indentations on a document. In this work, an EDD is used to detect latent physical markings left on documents by printers and photocopiers. Seventeen inkjet printers, 12 laser printers, and 3 photocopy machines were used to produce test documents. Physical markings were detectable in the large majority of the documents and were reproducible 100% of the time.
The Diversity of Dental Patterns in the Orthopantomography and Its Significance in Human Identification
Authors: Lee SS , Choi JH , Yoon CL , Kim CY , Shin KJ
Published: May 2004

The primary aim of this study was to evaluate the utility of orthopantomography for human identification. Three hundred orthopantomograms were randomly selected from those stored at Dental Hospital of Yonsei University in Seoul. Dental patterns observed in the orthopantomograms were converted into eight codes and their diversity was calculated. The diversity of dental patterns in the orthopantomogram data was 99.92% for full dentition and the diversity of mandible (99.28%) was slightly higher value than that of maxilla (98.22%). In the case of molars and premolars in both jaws, the diversity values ranged from 92.13% to 96.04%. It was founded that orthopantomography is a valuable means of personal identification not only based on full dentition but also when only the posterior teeth are available. The present study indicates that orthopantomography is excellent means of forensic identification.
Unusual Characteristic Patterns of Postmortem Injuries
Authors: Asamura H , Takayanagi K , Ota M , Kobayashi K , Fukushima H
Published: May 2004

Animal scavenging is one of the most significant causes of postmortem injuries. A large variety of scavenging animals have been reported on in previous papers. Although postmortem injuries attributable to birds are well known in the case of ”aerial burial,” the custom in Tibet, few cases of bird scavenging have been reported. In the two cases discussed herein, postmortem injuries were attributed to crows. Both cases, shared characteristic patterns of postmortem injuries, and in both cases death was attributed to fire. Although massive tissue loss by the crow scavenging made it difficult to determine the cause of the death and rendered personal identification difficult, 1 mL of blood drawn from the intracranial cavity and DNA analysis enabled this information to be determined, albeit with some difficulty.
Evaluation of 5-(4-Nitrophenyl)-2,4-pentadien-1-al (NPPD)as a Tracer for Shadowing Pursuits
Authors: Ohta H , Suzuki Y , Sugita R , Kasamatsu M , Marumo Y , Suzuki S
Published: May 2004

The chemical compound 5-(4-Nitrophenyl)-2,4-pentadien-1-al (NPPD), called “spy dust”, was usedin the Soviet Union as a shadowing pursuit, the act of following someone secretly, for investigating the activities of diplomatic personnel. It is also useful for counter-terrorism, and some criminal cases in the forensic science field. In this paper, it was synthesized and evaluated as a tracer for shadowing pursuits. The method for utilizing this reagent was very simple: it was dissolved in methanol (1 mg/mL) and sprayed on the restricted area. If the suspect was to enter this area or touched the sprayed material, NPPD was attached to the suspect's shoe surface or hands. The color examination was a two-steps process: first was the addition of 1 mL of a 0.1% naphthoresorcinol methanol solution to the methanol extracts of a methanol-contained cotton swab used to smear some surfaces of the suspect, and second, the addition of 1 mL of concentrated hydrochloric acid, which turned the solution dark red. The λmax of the colored solution was 510 nm, measured by ultraviolet-vis spectroscopy. Detection limits for three methods were determined: a visual method (detection limit 100 ng/3 mL), an ultraviolet-visible spectrometric method (detection limit 10 ng/3 mL), and a selected-ion-monitoring gas chromatographic/mass spectrometric method (detection limit 300 pg/injection). The forensic utility of NPPD was demonstrated for two simulated cases: a theft case and a case where NPPD was used as a tracer to prove that an automobile had entered a restricted area.

These examinations prove NPPD is a useful shadowing pursuit (spy dust) for the forensic science field.
NIST Bullet Signature Measurement System for RM (Reference Material) 8240 Standard Bullets
Authors: Ma L , Song J , Whitenton E , Zheng A , Vorburger T , Zhou J
Published: May 2004

A bullet signature measurement system based on a stylus instrument was developed at the National Institute of Standards and Technology (NIST) for the signature measurements of NIST RM (Reference Material) 8240 standard bullets. The standard bullets are developed as a reference standard for bullet signature measurements and are aimed to support the recently established National Integrated Ballistics Information Network (NIBIN) by the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI). The RM bullets are designed as both a virtual and a physical bullet signature standard. The virtual standard is a set of six digitized bullet signatures originally profiled from six master bullets fired at ATF and FBI using six different guns. By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine at NIST, 40 RM bullets were produced. In this paper, a comparison parameter and an algorithm using autoand cross-correlation functions are described for qualifying the bullet signature differences between the RM bullets and the virtual bullet signature standard. When two compared signatures are exactly the same (point by point), their cross-correlation function (CCF) value will be equal to 100%. The measurement system setup, measurement program, and initial measurement results are discussed. Initial measurement results for the 40 standard bullets, each measured at six land impressions, show that the CCF values for the 240 signature measurements are higher than 95%, with most of them even higher than 99%. These results demonstrate the high reproducibility for both the manufacturing process and the measurement system for the NIST RM 8240 standard bullets.
Comparison of Age Estimated from Degree of Racemization of Aspartic Acid, Glutamic Acid and Alanine in the Femur
Authors: Ohtani S , Yamada Y , Yamamoto T , Arany S , Gonmori K , Yoshioka N
Published: May 2004

Aspartic acid (Asp) is generally used for estimation of age by measuring the degree of racemization. For other amino acids, however, there are few reports regarding the usefulness of the degree of racemization for the estimation of age. Accordingly, in this study using the femur (obtained from 21 cadavers) as the specimen, we measured the degree of racemization of glutamic acid (Glu) and alanine (Ala) along with Asp in the total amino acid (TAA) fraction as well as in acid-insoluble collagen-rich (IC) and acid-soluble peptide (SP) sub-fractions. We compared the degrees of racemization of each amino acid and the accuracy of the ages estimated from them. The degree of racemization and the reaction rate of racemization were ranked in the order of Asp>Glu>Ala in the TAA and IC fractions, but Asp>Ala>Glu in the SP fraction. It is noteworthy that the degrees of racemization differed between the three amino acids depending on the fraction tested. The correlation coefficient (r) between the degree of racemization and the chronological age was higher in the SP than in the TAA or IC fraction. Among three amino acids, Asp showed the highest correlation coefficient as predicted. The present study confirmed that Asp from the SP fraction is the best indicator for age estimation using racemization rates.
Estimation of Postmortem Interval (PMI) as Revealed Through the Analysis of Annual Growth in Woody Tissue
Authors: Courtin GM , Fairgrieve SI
Published: May 2004

The discovery of human remains lying across a black spruce (Picea mariana) leader (branch) that subsequently grew up around the remains provided an opportunity to use the growth ring pattern to estimate the postmortem interval (PMI). As these remains were discovered in an advanced state of decomposition in October of 2000, and it was clear that relevant insect evidence was not forthcoming, this novel approach to estimating PMI was proposed. The asymmetrical growth of the leader resulted in a correspondingly asymmetrical pattern of its growth rings. As the date of cutting the leader was known, it was possible to evaluate the asymmetrical growth pattern to provide an estimation of PMI. Fine polishing of the cross section and computerized quantification of ring widths enabled an estimation of the displacement of the leader, and hence the time the decedent's body was so positioned. By charting the ring-width differential for the leader, it was concluded that the displacement occurred sometime between July of 1993 and May of 1994. The actual date of disappearance was confirmed to be August 24, 1993.