Why is it so difficult to determine the yield of indoor cannabis plantations? A case study from the Netherlands.
Forensic Sci Int. 2017 Mar 31;:
Authors: Vanhove W, Maalsté N, Van Damme P
Together, the Netherlands and Belgium are the largest indoor cannabis producing countries in Europe. In both countries, legal prosecution procedure of convicted illicit cannabis growers usually includes recovery of the profits gained. However, it is not easy to make a reliable estimation of the latter profits, due to the wide range of factors that determine indoor cannabis yields and eventual selling prices. In the Netherlands, since 2005, a reference model is used that assumes a constant yield (g) per plant for a given indoor cannabis plant density. Later, in 2011, a new model was developed in Belgium for yield estimation of Belgian indoor cannabis plantations that assumes a constant yield per m(2) of growth surface, provided that a number of growth conditions are met. Indoor cannabis plantations in the Netherlands and Belgium share similar technical characteristics. As a result, for indoor cannabis plantations in both countries, both aforementioned yield estimation models should yield similar yield estimations. By means of a real-case study from the Netherlands, we show that the reliability of both models is hampered by a number of flaws and unmet preconditions. The Dutch model is based on a regression equation that makes use of ill-defined plant development stages, assumes a linear plant growth, does not discriminate between different plantation size categories and does not include other important yield determining factors (such as fertilization). The Belgian model addresses some of the latter shortcomings, but its applicability is constrained by a number of pre-conditions including plantation size between 50 and 1000 plants; cultivation in individual pots with peat soil; 600W (electrical power) assimilation lamps; constant temperature between 20°C and 30°C; adequate fertilizer application and plants unaffected by pests and diseases. Judiciary in both the Netherlands and Belgium require robust indoor cannabis yield models for adequate legal prosecution of illicit indoor cannabis growth operations. To that aim, the current models should be optimized whereas the validity of their application should be examined case by case.
PMID: 28502714 [PubMed – as supplied by publisher]
Sex estimation with the total area of the proximal femur: A densitometric approach.
Forensic Sci Int. 2017 Mar 08;275:110-116
Authors: Curate F, Albuquerque A, Ferreira I, Cunha E
The estimation of sex is a central step to establish the biological profile of an anonymous skeletal individual. Imaging techniques, including bone densitometry, have been used to evaluate sex in remains incompletely skeletonized. In this paper, we present a technique for sex estimation using the total area (TA) of the proximal femur, a two-dimensional areal measurement determined through densitometry. TA was acquired from a training sample (112 females; 112 males) from the Coimbra Identified Skeletal Collection (University of Coimbra, Portugal). Logistic regression (LR), linear discriminant analysis (LDA), reduce error pruning trees (REPTree), and classification and regression trees (CART) were employed in order to obtain models that could predict sex in unidentified skeletal remains. Under cross-validation, the proposed models correctly estimated sex in 90.2-92.0% of cases (bias ranging from 1.8% to 4.5%). The models were evaluated in an independent test sample (30 females; 30 males) from the 21st Century Identified Skeletal Collection (University of Coimbra, Portugal), with a sex allocation accuracy ranging from 90.0% to 91.7% (bias from 3.3% to 10.0%). Overall, data mining classifiers, especially the REPTree, performed better than the traditional classifiers (LR and LDA), maximizing overall accuracy and minimizing bias. This study emphasizes the significant value of bone densitometry to estimate sex in cadaveric remains in diverse states of preservation and completeness, even human remains with soft tissues.
PMID: 28343024 [PubMed – as supplied by publisher]
Estimation of date of death through wound healing of an extraction socket: A case report.
Forensic Sci Int. 2017 Mar 27;:
Authors: Viciano J, D’Anastasio R, D’Ovidio C, Costantini S, Carnevale A, Capasso L
Surgical extraction of teeth due to dental pathologies is a relatively common procedure in modern man. The healing of the wound that results occurs in gradual and sequential stages, such that the analysis of this repair process can be very useful in forensic investigations on human remains. The following study reports on a particular case where the remodeling of a tooth socket allowed an estimation of the time that had elapsed from the day of the surgical extraction of the tooth to the time of death. The corpse was that of a woman of 34 years. It was in an advanced state of decomposition, as it was largely skeletonized. Macroscopic, radiographic, and histological examinations of the oral cavity showed the initial stages of alveolar bone remodeling of the first left mandibular molar, which was characterized by: (i) a small reduction in the vertical height of the vestibular surface with respect to the theoretical original position of the tooth; (ii) resorption of the intra-alveolar septum and lamina dura; and (iii) formation of new immature bone, which covered the entire inner surface of the socket. This study established that the subject died 13-42days after the tooth extraction. Knowing the date of the dental extraction provided by the police investigation, it was possible to provide an estimate of the date of death.
PMID: 28390826 [PubMed – as supplied by publisher]
An exploratory study of the potential of LIBS for visualizing gunshot residue patterns.
Forensic Sci Int. 2017 Feb 21;273:124-131
Authors: López-López M, Alvarez-Llamas C, Pisonero J, García-Ruiz C, Bordel N
The study of gunshot residue (GSR) patterns can assist in the reconstruction of shooting incidences. Currently, there is a real need of methods capable of furnishing simultaneous elemental analysis with higher specificity for the GSR pattern visualization. Laser-Induced Breakdown Spectroscopy (LIBS) provides a multi-elemental analysis of the sample, requiring very small amounts of material and no sample preparation. Due to these advantages, this study aims at exploring the potential of LIBS imaging for the visualization of GSR patterns. After the spectral characterization of individual GSR particles, the distribution of Pb, Sb and Ba over clothing targets, shot from different distances, were measured in laser raster mode. In particular, an array of spots evenly spaced at 800μm, using a stage displacement velocity of 4mm/s and a laser frequency of 5Hz was employed (e.g. an area of 130×165mm(2) was measured in less than 3h). A LIBS set-up based on the simultaneous use of two spectrographs with iCCD cameras and a motorized stage was used. This set-up allows obtaining information from two different wavelength regions (258-289 and 446-463nm) from the same laser induced plasma, enabling the simultaneous detection of the three characteristic elements (Pb, Sb, and Ba) of GSR particles from conventional ammunitions. The ability to visualize the 2D distribution GSR pattern by LIBS may have an important application in the forensic field, especially for the ballistics area.
PMID: 28267647 [PubMed – as supplied by publisher]
The precision of micro-tomography in bone taphonomic experiments and the importance of registration.
Forensic Sci Int. 2017 Feb 15;:
Authors: Le Garff E, Mesli V, Delannoy Y, Colard T, De Jonckheere J, Demondion X, Hédouin V
Micro-computed tomography (μCT) provides micrometric 3D images and has been used in forensic studies for anthropology pubis measurement or insect description for post mortem interval estimation. Studies have suggested using registration, a superimposing images method between a reference and a target. This technique avoids positioning bias and increase the precision of μCT. However, no clear study has reported the precision with μCT analysis before or after registration in a forensic field. One fresh post mortem sample of a human cranial vault was collected. Two successive μCT acquisitions (resolution 10μm) of it were performed without repositioning. The data from the second acquisition were copied and registered by two trained operators (operators 1 and 2). Operator 1 performed a second registration process after 1 week (operator 1 bis). The images were analysed. The bone volume (BV), bone surface (BS), number of trabeculae (TbN), trabecular thickness (TbTh) and mean trabecular distance (TbSp) were compared before and after registration. The mean (±SD), the coefficient of variation (%CV), and the precision error of the standard deviation absolute value and of the coefficient of variation between operators 1 and 2 (inter-subject variability) and between operator 1 and 1 bis (intra-subject variability) were calculated. We also collected the second phalanx of the 2nd, 3rd and 4th fingers on the hands of a second individual. Two successive scans (resolution 27μm) were performed without repositioning. A comparison (mean±SD of BV, BS, TbN, TbTh, TbSp) was made between the first and second scans with and without registration, and an ANOVA repeated measures procedure was performed. For the vault, we show that after 30 registrations for each operator (1, 2 and 1 bis), the mean and %CV were very close for each variable and between operators. For BV and BS, the difference in the mean value was approximately 0.01 (mm(3) and mm(2), respectively). The precision error was higher in the inter-subject registrations for each variable. The precision error magnitude for all variables was very low (<0.01) in absolute value and of %CV. For the fingers, the difference between the first and second scans may be approximately 50% without registration. We found that the second scan without registration is significantly different for BV (p=0.006), BS (p=0.007), TbN (p=0.019) and TbSp (p=0.002). Knowing the precision of the device (with and without registration) is important to ensure that the accuracy of the μCT results.
PMID: 28237440 [PubMed – as supplied by publisher]
Time related changes of T1, T2, and T2(*)(2) of human blood in vitro.
Forensic Sci Int. 2016 May;262:11-7
Authors: Petrovic A, Krauskopf A, Hassler E, Stollberger R, Scheurer E
In view of a potential future use for dating hemorrhage in forensic medicine the correlation of MR relaxation parameters with time was evaluated in blood samples. A systematic relationship could be valuable for using MRI for estimating the age of hemorrhage and soft tissue hematomas particularly in clinical forensic medicine. Relaxation times T1, T2, and T2(*) of venous blood samples from 6 volunteers were measured using 3T MRI regularly up to 30 days. The time progression of the relaxation parameters was systematically analyzed and examined for possible interrelations. T2 initially decreased to a minimum, and then increased again (range 24-97ms), while T1 started with a plateau phase followed by an almost linear decrease (range 333-2153ms). T2(*) remained relatively constant during the entire investigation period. The higher the initial T2 was, the lower was its minimum, and the greater was the decrease of the associated T1. The inter- and intra-individual variability was relatively large, one reason being very likely the metabolic differences in the blood samples. The observed characteristic changes in blood samples over time measured by quantitative MR techniques add objective information in view of an estimation of the age of hemorrhage. However, in vivo studies will be needed to verify the data with respect to influencing metabolic factors.
PMID: 26953500 [PubMed – indexed for MEDLINE]
Variation in osteon histomorphometrics and their impact on age-at-death estimation in older individuals.
Forensic Sci Int. 2016 May;262:282.e1-6
Authors: Goliath JR, Stewart MC, Stout SD
Histomorphometric studies have reported relations between osteon size and age; however, data focused on the shape of osteons is sparse. The purpose of this study was to determine how osteon circularity (On.Cr) varies with age in different skeletal elements. Regression analysis was used to evaluate the relationship between age and osteon shape and size. We hypothesized that age would be negatively related to osteon size (area, On.Ar) and positively related to osteon shape (On.Cr). On.Cr and On.Ar were determined for the ribs and femora of 27 cadaveric specimens with known age-at-death. As predicted, age was significantly related to osteon size and shape for both the femur and rib. With age, there was a decrease in size and an increase in circularity. No relationship between sex and On.Cr was detected. An age predicting model, including On.Cr, On.Ar and OPD, is proposed to improve our ability to estimate age-at-death, especially for older individuals.
PMID: 27021159 [PubMed – indexed for MEDLINE]
Estimation of time since death by vitreous humor hypoxanthine, potassium, and ambient temperature.
Forensic Sci Int. 2016 May;262:160-5
Authors: Rognum TO, Holmen S, Musse MA, Dahlberg PS, Stray-Pedersen A, Saugstad OD, Opdal SH
Measurement of vitreous humor potassium (K(+)) has since the 1960s been recognized as an adjunct for estimation of time since death. In 1991 we introduced hypoxanthine (Hx) as a new marker. Furthermore we demonstrated that time since death estimation was more accurate when ambient temperature was included in the calculations, both for K(+) and for Hx. In this paper we present a refined method. The subjects consist of 132 cases with known time of death and ambient temperature. One sample from each subject was used in the calculations. Vitreous humor Hx levels were available in all subjects, while K(+) was measured in 106 of the subjects, due to insufficient volume of vitreous humor. Linear regression analysis was applied to model the correlation between vitreous humor Hx and K(+), taking the interactions with temperature into consideration. The diagrams published in 1991, which also included ambient temperature, estimated median time since death with range between the 10th and 90th percentile, whereas the linear regression analysis presented in this paper estimates mean time since death with a corresponding 95% interval of confidence. We conclude that time since death may be estimated with relatively high precision applying vitreous humor Hx and K(+) concentrations combined with ambient temperature.
PMID: 26994446 [PubMed – indexed for MEDLINE]
Selecting best-fit models for estimating the body mass from 3D data of the human calcaneus.
Forensic Sci Int. 2016 May;262:37-45
Authors: Jung GU, Lee UY, Kim DH, Kwak DS, Ahn YW, Han SH, Kim YS
Body mass (BM) estimation could facilitate the interpretation of skeletal materials in terms of the individual’s body size and physique in forensic anthropology. However, few metric studies have tried to estimate BM by focusing on prominent biomechanical properties of the calcaneus. The purpose of this study was to prepare best-fit models for estimating BM from the 3D human calcaneus by two major linear regression analysis (the heuristic statistical and all-possible-regressions techniques) and validate the models through predicted residual sum of squares (PRESS) statistics. A metric analysis was conducted based on 70 human calcaneus samples (29 males and 41 females) taken from 3D models in the Digital Korean Database and 10 variables were measured for each sample. Three best-fit models were postulated by F-statistics, Mallows’ Cp, and Akaike information criterion (AIC) and Bayes information criterion (BIC) for each available candidate models. Finally, the most accurate regression model yields lowest %SEE and 0.843 of R(2). Through the application of leave-one-out cross validation, the predictive power was indicated a high level of validation accuracy. This study also confirms that the equations for estimating BM using 3D models of human calcaneus will be helpful to establish identification in forensic cases with consistent reliability.
PMID: 26970867 [PubMed – indexed for MEDLINE]
Sex estimation based on scapula analysis in a Japanese population using multidetector computed tomography.
Forensic Sci Int. 2016 May;262:285.e1-5
Authors: Torimitsu S, Makino Y, Saitoh H, Sakuma A, Ishii N, Yajima D, Inokuchi G, Motomura A, Chiba F, Yamaguchi R, Hashimoto M, Hoshioka Y, Iwase H
Accurate sex estimation based on measurements of dimorphic dimensions in human unknown remains is important as the first step toward making individual identification. The purpose of this study was to assess the sexual dimorphism of the scapula and to quantify the accuracy of sex estimation in a contemporary Japanese forensic sample using scapular measurements based on three-dimensional (3D) computed tomographic (CT) images. A total of 218 cadavers (109 males, 109 females) that underwent postmortem CT and subsequent forensic autopsy were used. Ten scapular measurements were performed on 3D CT reconstructed images that extracted only bone data, and were analyzed using descriptive statistics and discriminant function analyses (DFA). All measurements were dimorphic in terms of sex differences. Univariate DFA provided sex classification accuracy rates of 75.7-91.3%. Stepwise DFA yielded sex prediction accuracy rates of 93.1-94.5%. In conclusion, the scapular measurements using 3D CT images of a contemporary Japanese population may be useful for the estimation of skeletal sex in the field of forensic anthropology.
PMID: 26965402 [PubMed – indexed for MEDLINE]