ABSTRACT
Megaselia scalaris (Loew) (Diptera: Phoridae) is a cosmopolitan scuttle fly of medical and forensic importance. This species is generally small, humpbacked and is a prominent decomposer of corpses indoors. Taxonomically, adult sexes can be distinguished based on the characteristics of the terminal segments of the abdomen. In this report, the terminalia of adult male and female M. scalaris were examined using scanning electron microscope (SEM). The terminal segment of an adult female is less complex compared to male, consisting of an ovipositor and cerci. In male, the hypopygium consists of epandrium, hypandrium, anal tube and penis complex. A pair of long and feathered setae was attached to the tip of the anal tube and tapered. The application of SEM to identify this species isuseful and can be expanded to other species in this fly group.
Subject(s)
Microscopy, Electron, ScanningABSTRACT
Identifi cation of unknown suspect through bite marks has always been challenging. Narrowing list of suspects through sex and race markers is always recommend but rarely utilized due to limited publication in this area. Thus, this preliminary research was aimed to study the difference of bite mark made on dental wax between sex and race. A sample size of 40 UKM undergraduates comprising of Malay (male = 10, female = 10) and Chinese (male = 10, female = 10) were used in this study. Bite mark of subject was obtained through dental wax, digitally scanned and analyzed using Image-J software. Parameters measured were anterior teeth size, intercanine width and anterior teeth relative rotation. Result indicated that mandible left canine tooth size had signifi cant sexual dimorphism (p < 0.05) in differentiating sex. The means for male and female measured were 4.63 ± 1.05 mm and 5.35 ± 0.87 mm respectively. In addition to the result, tooth size of maxillary left canine and mandible left lateral incisor were signifi cantly different (p < 0.05) between races. Means for mandible left canine Malay and Chinese were 5.27 ± 1.01 mm and 4.50 ± 1.22 mm respectively. Furthermore, left lateral incisor mandible had means of 5.15 ± 0.87 mm and 4.60 ± 0.74 mm for Malay and Chinese respectively. Unfortunately, there were no signifi cant differences for intercanine width and anterior teeth relative rotation between the two major races in Malaysia. In conclusion, this research has demonstrated the possibility of using tooth size of mandible left canine, maxillary left canine and mandible left lateral discriminate sex and race.
Subject(s)
ToothABSTRACT
Post mortem changes are important in estimating post mortem interval (PMI). This project’s aim was to study the effect of burial and type of clothing on rate of decomposition, which can contribute to estimating PMI for victims. 12 rabbits (Oryctolagus cuniculus) carcasses were separated into 3 groups: no clothing, light clothing and heavy clothing. Control subjects were placed on the ground surface while test subjects were buried at 30 cm depth graves. Soil samples prior and after decomposition were collected for soil pH and moisture analysis. Post mortem change was assessed using a Total Body Score system. The head, neck and limb regions were found to decay faster than the body trunk region. Mummifi cation occurred on body parts that were exposed directly to the atmosphere while adipocere formed on some buried subjects. Burial delayed decomposition due to lower insect activity and lower soil temperature. The soil layer also blocked the accessibility of majority of the arthropods, causing further delay in decomposition. Clothing enhanced decay for bodies on ground surface because it provided protection for maggots and retained moisture on tissues. However, clothing delayed decomposition in buried bodies because it physically separated the bodies from soil and arthropods. Higher sun exposure and repetitive exhumation showed acceleration of decomposition. The decomposition process increased soil pH and moisture percentage values. Soil pH initially increased until pH 8.0-8.4 followed by a slight decrease while soil moisture percentage changed inconsistently. Burial was signifi cant in affecting post mortem change, F(1,11)=12.991, p<0.05 while type of clothing was not signifi cant, F(2,9)=0.022, p=0.978 and combination of both type of clothing and burial factors were also not signifi cant, F(2,3)=0.429, p=0.686. For validation, an accuracy of 83.33% was achieved based on soil pH and soil moisture percentage analysis.
ABSTRACT
Determination of races in the analysis of hair on scalp is one of the challenges faced in forensic analysis to identify victims, suspects and crime scene. This study aimed to determine the differences among the two main races in Malaysia which included Malay and Chinese, through the examination of the characteristics of hair. These includes general features of the hair, patterns of cuticle, colors, cortex pigment distribution and characteristics of medulla - types, thickness and medulla index. This study was carried out by using a light microscope and consisted of five steps, which were sample preparation, examination of common features of hair, preparation and examination of cuticle scales matrix, cortex and medulla. Result showed that most of the Malay have dark brown pigments while Chinese have pigments of light brown color. We also noted that thickness of medulla can also be used to differentiate between Malay and Chinese where average values for Malay and Chinese are 7.59 ± 1.45 μm and 9.12 ± 1.85 μm, respectively. The average values of medulla index for Malay and Chinese were noticeably different at 0.17 ± 0.02 μm and 0.18 ± 0.02 μm, respectively. However, textures, thickness of hair, patterns of cuticle scales, and types of medulla do not show any significant difference between Malay and Chinese. In conclusion, this study has shown that pigment colors, thickness of medulla and medulla index are important characteristics that can be used to determine race