The optimisation of fingermark enhancement by VMD and Lumicyano™ on thermal paper

The enhancement of fingermarks on thermal paper can be challenging due to background staining caused by polar solvents used in fingermark enhancement techniques such as ninhydrin. This study explored a commercial one-step superglue fuming process, Lumicyano™, and Vacuum Metal Deposition (VMD) to develop fingermarks on this substrate and overcome this issue. Different sequential treatments involving Lumicyano™ and a combination of VMD methods were investigated with varying degrees of success with some sequences being highly sensitive. The VMD processes, however, were observed to generally be more effective at enhancing marks, whereas Lumicyano™ provided little or no benefit on this paper type. The results indicate that Lumicyano™ is only beneficial as a pre-treatment when the entire sequence of gold/zinc and silver/zinc is taken to completion. The gold/zinc and silver/zinc VMD processes were optimised on five different thermal papers, and the optimised techniques were then directly compared to determine which was more successful on each thermal paper type as a single treatment.     

A Rationale and Method for Examining Reasons for Linkages Among Adolescent Risk Behaviors

A large volume of research has investigated interrelations among adolescent risk behaviors. Although several theoretical accounts have been proposed, researchers have not directly examined hypotheses for why risk behaviors are linked. In the present paper, a distinction is drawn between predictive factors that explain variance in risk behaviors and “linkage factors” which may provide an explanation for why risk behaviors are interrelated. The relevance of linkage factors to risk behavior research, theory, and practice is described. Further, a simple to use and easy to interpret analytic technique for exploring linkage-related issues is illustrated. Using this technique, hypotheses regarding the role of predictors in explaining linkages among risk behaviors can be tested directly. The proposed line of inquiry will provide valuable input for intervention efforts and theoretically relevant information concerning linkages among adolescent risk behaviors. Research Associate at the Brock Research Institute for Youth Studies at Brock University, Ontario, Canada. He received his M.A. in Clinical Psychology from the University of North Dakota. His major research interests are adolescent risk behavior involvement and youth activity involvement as a context for positive development. Professor in the Department of Child and Youth Studies at Brock University, Ontario, Canada. She received her Ph.D. in Developmental Psychology from the University of Waterloo. Her major research interests include adolescent risk taking and resilience, including academic underachievement and media/technology influences on lifestyle choices and learning. Assistant Professor in the Department of Child and Youth Studies at Brock University, Ontario, Canada. She received her Ph.D. in Developmental Psychology from Brock University. Her major research interests are adolescent risk-behavior involvement, particularly related to gambling, and risk and resilience.     

小学生学习书法的心理偏差分析

经过大量的社会调查,发现大多数学习书法的小学生是在众多的压力之下,同时又是在缺少愉快心理的过程中度过的。为什么欣赏起来赏心悦目的书法,学起来却令人痛苦不堪呢?这主要是小学生学习书法的心理偏差造成的,只有消除偏差,才能培养他们学习书法的积极性。     

Profiles of Victimized Women Among the Child Welfare Population: Implications for Targeted Child Welfare Policy and Practices

Despite the call to address domestic violence along with child maltreatment, little information exists to guide services for victimized women involved with child welfare. Research shows that victimized women contend with multiple problems stemming from violent victimization. Unfortunately less is known about combinations of needs and resources among victimized women, especially for those involved with child welfare. Through an examination of needs and resources among families with child maltreatment and domestic violence, we aimed to help address this knowledge gap. Needs and resources among 1,229 victimized caregivers were examined using the National Survey of Child and Adolescent Well-being (NSCAW). Using latent class analysis, four distinct multivariate profiles of needs and resources among victimized caregivers were identified. Significant differences were found among the profile groups in the family violence they experienced in the 18 months following child welfare investigations. Based on these findings, we discuss implications for tailored practices to enhance the safety of victimized caregivers involved with child welfare. An earlier version of this paper was presented at the 9th Annual Conference of the Society for Social Work and Research, Miami, Florida in January 2005.     

纸张上潜在手印三种前处理方法对DNA检验的影响

目的通过比较常见纸张上潜在手印盲提法与显现后精准提取法的接触DNA检出率,探讨常见纸张上接触DNA前处理的优选方案。方法比较五种常见纸张上使用盲提法和显现潜在手印(茚二酮显现法、茚三酮熏显法)后精准提取法采集的接触DNA样本检出率。结果粗糙日历纸盲提的接触DNA检出率为17.8%,通过茚二酮法和茚三酮法显现的潜在手印所提取的DNA检出率分别为75.6%、77.8%;光滑日历纸三种方法所提取的接触DNA检出率为4.4%、11.1%、11.1%;A4复印纸三种方法接触DNA检出率为20%、37.8%、66.7%;牛皮纸三种方法接触DNA检出率为20%、68.9%、64.4%;快递纸袋的三种方法接触DNA检出率为2.2%、6.7%、46.7%。结论不同纸张上潜在手印经显现后接触DNA检出率不同,通过茚二酮或茚三酮显示潜在手印后精准提取DNA的前处理方法相较于盲提法的接触DNA检出率高。实战中可应用此类方法同时获得手印与DNA分型,以有效提高证据力。     

The dynamic political economy of support for Barack Obama during the 2008 presidential election campaign

In recent years, students of voting behavior have become increasingly interested in valence politics models of electoral choice. These models share the core assumption that key issues in electoral politicds typically are ones upon which there is a widespread public consensus on the goals of public policy. The present paper uses latent curve modeling procedures and data from a six-wave national panel survey of the American electorate to investigate the dynamic effects of voters’ concerns with the worsening economy—a valence issue par excellence—in the skein of causal forces at work in the 2008 presidential election campaign. As the campaign developed, the economy became the dominant issue. Although the massively negative public reaction to increasingly perilous economic conditions was not the only factor at work in 2008, dynamic multivariate analyses show that mounting worries about the economy played an important role in fueling Barack Obama’s successful run for the presidency.     

A Preliminary Study on Vacuum Metal Deposition as a Standalone Method for Enhancement of Fingermarks on Ballistic Brass Materials

In order to assess the efficacy of vacuum metal deposition (VMD) as a technique to develop fingermarks on ballistic metallic surfaces, a preliminary study using six donors (three male & three female) was conducted. Using a sequential metal deposition process, two metal combinations were studied—gold/zinc and silver/zinc. Results indicate the potential of this technique, by developing identifiable fingermarks on brass metal disks aged from a few days up to more than a month old. As the development of fingermarks on fired (brass) cartridge cases is an area of interest, a further study was conducted where a total of 20 fingermarks were deposited on cases. After firing, second level fingermark characteristics were successfully observed on cartridge cases highlighting its potential as a fingermark enhancement method for ballistic brass materials. Further work is required to fully evaluate the VMD process and its reliability as a fingermark enhancing method on ballistic surfaces.     

Latent Fingermark Aging Patterns (Part IV): Ridge Width as One Indicator of Degradation

This fourth article of the series is taking an in‐depth analysis at the visible aging of latent fingermarks regarding changes in ridge widths over time. The objective is to quantify and statistically describe significant ridge size variations under controlled indoor conditions. The effect of three environmental variables are examined: type of secretion (sebaceous‐ and eccrine‐rich) and type of substrate (glass and polystyrene) when aged in three light conditions (direct natural light, shade, and dark). Prior to width measurements, fresh and aged fingermarks were powdered with titanium dioxide (TiO₂) and sequentially photographed at predetermined times over 6 months. Three independent observers measured the ridges from thirty predetermined locations using strategically placed intersecting lines on the print. Results indicate that fingermarks deposited on glass are more resilient to degradation compared with those deposited on plastic. The presence of direct natural light plays a negligible role on degradation compared to secretion and substrate types.     

Inherent Fluorescence Detection of Latent Fingermarks by Homemade Shortwave Ultraviolet Laser

Detection of latent fingermarks on various substrates is critical in crime investigations. Conventional chemical methods using reagents could contaminate or even destruct biological information of samples. Here, an optical method and successful case application of detecting latent fingermarks through long‐wave ultraviolet (UV) fluorescence (300–400 nm) by shortwave UV laser excitation is reported. Experimental results indicate that the recovery rate of the latent fingermarks on various paper items is in the range of 70–80% without chemical treatments. Moreover, the optical method allows for the preservation of samples for further examination, such as polymerase chain reaction (PCR) testing. The technique has also been successfully applied to a criminal case in identifying the suspect, which, to the best of our knowledge, has never been reported in real crime investigations. Therefore, such a method as UV‐excited UV fluorescence in detecting latent fingermarks may be better for examination in cases where biological information of samples is needed for consequent testing.     

Laser desorption/ionization time-of-flight mass spectrometry of triacylglycerols and other components in fingermark samples

The chemical composition of fingermarks could potentially be important for determining investigative leads, placing individuals at the time of a crime, and has applications as biomarkers of disease. Fingermark samples containing triacylglycerols (TAGs) and other components were analyzed using laser desorption/ionization (LDI) time-of-flight mass spectrometry (TOF MS). Only LDI appeared to be useful for this application while conventional matrix-assisted LDI-TOF MS was not. Tandem MS was used to identify/confirm selected TAGs. A limited gender comparison, based on a simple t-distribution and peaks intensities, indicated that two TAGs showed gender specificity at the 95% confidence level and two others at 97.5% confidence. Because gender-related TAGs differences were most often close to the standard deviation of the measurements, the majority of the TAGs showed no gender specificity. Thus, LDI-TOF MS is not a reliable indicator of gender based on fingermark analysis. Cosmetic ingredients present in some samples were identified.