Validation of thin layer chromatography with AccuTOF-DART™ detection for forensic drug analysis

Abstract: Thin layer chromatography (TLC) is a technique that is commonly employed in the forensic drug analysis of pharmaceutical preparations. Detection is typically accomplished using various visualization spray reagents. Conventional gas chromatography–mass spectrometry (GC‐MS) analysis is typically performed to confirm the TLC results. Depending on the drugs tested and the instrument conditions required, this confirmation can take up to an hour to complete. Direct analysis in real time (DART?) is an ionization source, coupled to an accurate‐mass time‐of‐flight mass spectrometer that has the capability to ionize materials under ambient conditions. To streamline analysis, the combination of TLC with DART? detection is proposed to screen and subsequently identify drug compounds, all from the same TLC plate. DART? confirmations of TLC analyses take <10 min to complete and compare favorably to GC‐MS in sensitivity and selectivity. This study validates the use of TLC‐DART in the forensic identification of the components of several pharmaceutical preparations.     

Rapid screening for the detection and differentiation of γ-hydroxybutyrate using ion chromatography

The analysis of gamma-hydroxybutyric acid (GHB) is problematic because it is hygroscopic, it lacks a good UV chromophore, and it undergoes heat-induced cyclization. This paper presents a new method utilizing ion-exchange chromatography (IC) with conductivity detection. The simple sample preparation, rapid analysis time, and inorganic anion detection capabilities are all advantages over the current methods. The detection of inorganic salts (formed during GHB synthesis) gives insight into the synthetic route utilized and can aid in drug seizure comparison. The developed method has a detection limit for GHB anions of 0.57 mg/L and chloride of 0.22 mg/L. A comparison of this technique with a current gas chromatography-mass spectrometry technique is presented, and a t-test found that the two methods' results are not statistically different at the 99.9% confidence level demonstrating the merits of this fast, simple, and informative IC method as a routine screening tool.     

Mitochondrial DNA sequencing of cat hair: an informative forensic tool

Approximately 81.7 million cats are in 37.5 million U.S. households. Shed fur can be criminal evidence because of transfer to victims, suspects, and/or their belongings. To improve cat hairs as forensic evidence, the mtDNA control region from single hairs, with and without root tags, was sequenced. A dataset of a 402-bp control region segment from 174 random-bred cats representing four U.S. geographic areas was generated to determine the informativeness of the mtDNA region. Thirty-two mtDNA mitotypes were observed ranging in frequencies from 0.6-27%. Four common types occurred in all populations. Low heteroplasmy, 1.7%, was determined. Unique mitotypes were found in 18 individuals, 10.3% of the population studied. The calculated discrimination power implied that 8.3 of 10 randomly selected individuals can be excluded by this region. The genetic characteristics of the region and the generated dataset support the use of this cat mtDNA region in forensic applications.     

DNAc: A clustering method for identifying kinship relations between DNA profiles using a novel similarity measure

After decades of refinement, DNA testing methods have become essential tools in forensic sciences. They are essentially based on likelihood ratio test principle, which is utilized specifically, by using as prior knowledge the allele frequencies in the population, to confirm or refute a given kinship hypothesis made on two genotypes. This makes these methods ill suited when allele frequencies or kinship hypotheses are unavailable. In this paper, we introduce DNAc, a new clustering methodology for DNA testing based on a new similarity measure that allows an accurate retrieval of the degree of relatedness among two or more genotypes, without relying on kinship hypotheses or allele frequencies in the population. We used DNAc in analyzing microsatellite DNA sequences distributed among 12 genotypes from normal individuals from two distinct families. The results show that DNAc accurately determines kinship among genotypes and further gathers them in the appropriate kinship groups.     

Sickle cell trait-associated deaths: a case series with a review of the literature

This study presents a series of 16 carriers of hemoglobin S (HbS) who died during various circumstances. Many of the cases were associated with mild to moderate exertion. The onset and/or duration of symptoms varied from a few minutes to several hours with many displaying a prolonged lucid interval with stable vital signs. Despite seeking medical treatment, sickle cell trait-related micro-occlusive crisis was never considered in the differential diagnosis. Several cases were associated with sudden death. In those deaths which were delayed, high anion gap and uncompensated metabolic acidosis were typical and were not heat related. Also characteristic were large increases in creatine kinase, alanine aminotransferase, and aspartate aminotransferase along with myoglobinemia. Although the antemortem diagnosis of rhabdomyolysis was made, the underlying cause was never deduced by the clinicians. The sickling found at autopsy is not always a postmortem artifact, and in the right circumstances can be diagnostic.     

Temporal variation of oxygen isotope ratios (δ18O) in drinking water: implications for specifying location of origin with human scalp hair

Previous work suggests that δ(18)O values of human hair can be used to constrain the region-of-origin of unknown individuals, but robust assessments of uncertainties in this method are lacking. Here we assess one source of uncertainty - temporal variation in the δ(18)O value of drinking water - using a monthly tap water survey of δ(18)O to develop geospatial models (i.e., maps) of the intra-annual variation (seasonality) in tap water δ(18)O for the contiguous USA. Temporal variation in tap water δ(18)O was correlated with water-supply type, and was related to geographic patterns of precipitation δ(18)O seasonality and water residence time. The maps were applied in a Bayesian framework to identify the geographic origin of an unidentified woman found in Utah, based on measured δ(18)O of scalp hair. The results are robust in specifying parts of the western USA as the most likely region-of-origin. Incorporation of tap water δ(18)O seasonality in the analysis reduces the precision of geographic assignments, but other sources of uncertainty (e.g., spatial interpolation uncertainty) have an equal or larger effect.     

Using iPhones? to Enhance and Reduce Face-to-face Home Safety Sessions within SafeCare?: An Evidence-based Child Maltreatment Prevention Program

Innovative handheld technologies are changing the possibilities for public health interventions. The present research describes a preliminary examination of the iPhone? when used as an assessment tool and an enhancement to an evidence-based, in-home child safety intervention. Three families with young children received an augmented version of the Safety module of SafeCare, a home-visiting child maltreatment prevention program. Specifically, parents were trained to use an iPhone to video rooms in their homes, as well as communicate feedback, logistics, and safety content between the home visitor and parent. The effectiveness of iPhone and video was examined using a multiple baseline design across in-home settings replicated across families. Home hazards were reduced dramatically across rooms and across participants. Face-to-face time of the home visitor was progressively reduced and replaced by video data collection. These data suggest smartphones are promising for data collection and for augmenting face-to-face interactions. Implications for reducing costs as smartphones become increasingly ubiquitous and for engaging and retaining participants are discussed.     

Construct validity,reliability and predictive validity of the dynamic risk assessment and management system (DRAMS) in offenders with intellectual disability

Background. There have been a number of developments in the assessment of dynamic risk in the criminological literature. The dynamic risk assessment and management system (DRAMS) has been developed to facilitate the measurement of dynamic factors of risk for offenders with intellectual disability. Method. The study was designed to assess the construct validity, reliability and predictive utility of the DRAMS in 23 male forensic patients in a high secure setting. Predictions were made against independently collected incident data. Concurrent validity was assessed against the Ward Anger Rating Scale (WARS). Results. A reformulation of the individual section variables according to convergent and discriminant correlational analysis revealed Cronbach's alpha levels of >.8 for all sections apart from mood (alpha .750) and items retained to facilitate clinical information (alpha ?.017). Two hundred pairs of WARS and DRAMS assessments revealed orderly sectional correlations. The sections of mood, antisocial behaviour, and intolerance/agreeableness predicted incidents with a medium effect size as did total DRAMS score. There were highly significant differences between assessments taken 1 or 2 days prior to an incident and control assessments conducted at least 7 days from an incident. Conclusions. The reformulated DRAMS has good construct and concurrent validity. It appears to be a reliable assessment tool and informs on risk levels relating to stable and acute proximal factors. It appears as an important addition to the utility of risk assessments for this population.     

从宪法角度看社会行动者对国家决定的影响

本文在通过分析社会、国家决定和宪法立法的概念,通过德国法学思想区分国家和社会两个概念的历史,在当代德国宪法确立的国家和社会相分离的基础上,讨论了社会行动者对国家立法、行政、司法三方面决定的影响,着重从规范和政治评价的角度,分析了与这些影响密切相关的机会和风险,表明宪法在维持机会和风险之间平衡具有不可或缺的地位。本文作者希望德国的经验对中国建设法治国家有所帮助。