Mathematically optimal decisions in forensic age assessment

Forensic age estimation generally involves considerable amounts of uncertainty. Forensic age indicators such as teeth or skeleton images predict age only approximately, and this is likely to remain true even for future forensic age indicators. Thus, forensic age assessment should aim to make the best possible decisions under uncertainty. In this paper, we apply mathematical theory to make statistically optimal decisions to age assessment. Such an application is fairly straightforward assuming there is a standardized procedure for obtaining age indicator information from individuals, assuming we have data from the application of this procedure to a group of persons with known ages, and assuming the starting point for each individual is a probability distribution describing prior knowledge about the persons age. The main problem is then to obtain such a prior. Our analysis indicates that individual priors rather than a common prior for all persons may be necessary. We suggest that caseworkers, based on individual case information, may select a prior from a menu of priors. We show how information may then be collected over time to gradually increase the robustness of the decision procedure. We also show how replacing individual prior distributions for age with individual prior odds for being above an age limit cannot be recommended as a general method. Our theoretical framework is applied to data where the maturity of the distal femur and the third molar is observed using MRI. As part of this analysis we observe a weak positive conditional correlation between maturity of the two body parts.

     

Ultrasound-guided central venous cannulation in infants and children

BACKGROUND: Percutaneous central venous cannulation in infants and children is a challenging procedure. Traditionally, an external landmark technique has been used to identify puncture site. An ultrasound-guided technique is now available and we wanted to evaluate this method in children and infants, looking specifically at the ease of use, success rate and complications. METHODS: Forty-two consecutive infants and children (median 16.5 [0-177] months and 10 [3-45] kg) scheduled for central venous catheter placement were registered. An ultrasound scanner made for guiding puncture of vessels was used. After locating the puncture site, a sterile procedure was performed using an accompanying kit to aid puncture of the vessel. RESULTS: Cannulation was successful in all patients and we had no complications during insertion of the catheters. The right internal jugular vein was preferred in most patients, and in 95% of the patients the vein was punctured at the first attempt. The median time from start of puncture to aspiration of blood was 12 (3-180) seconds. CONCLUSION: The ultrasound-guided technique for placement of central venous catheters was easy to apply in infants and children. It is our impression that it increased the precision and safety of the procedure in this group of patients.     

Effects of n-3 fatty acids in subjects with type 2 diabetes: reduction of insulin sensitivity and time-dependent alteration from carbohydrate to fat oxidation

BACKGROUND: Effects of fish oil supplements on metabolic variables are insufficiently clarified in type 2 diabetes. OBJECTIVE: We aimed to investigate short-term (1 wk) and longer-term (9 wk) effects of n-3 fatty acids. DESIGN: Twenty-six subjects with type 2 diabetes without hypertriacylglycerolemia participated in a double-blind controlled study. Median intake in the intervention group was 17.6 mL fish oil/d (1.8 g 20:5n-3, 3.0 g 22:6n-3, and 5.9 g total n-3 fatty acids). The control group received 17.8 mL corn oil/d (8.5 g 18:2n-6). RESULTS: Plasma phospholipid 20:5n-3 and 22:6n-3 increased, whereas 18:2n-6 decreased, in the fish oil group compared with the corn oil group after 1 wk. The two n-3 fatty acids also increased in adipose tissue biopsy samples taken after 9 wk in the fish oil group. Glucose concentrations (home-monitored) were approximately 1 mmol/L higher in the fish oil group than in the corn oil group at the end of the intervention (P = 0.035). Glucose utilization measured by using an isoglycemic clamp was lowered in the fish oil group compared with that in the corn oil group at the end of the intervention (P = 0.049), whereas glucagon-stimulated C-peptide tended to increase (P = 0.078). The fish oil group utilized less fat for oxidation after 1 wk, with a change to more fat and less carbohydrate oxidation after 9 wk (P = 0.040), than did the corn oil group. CONCLUSION: A high intake of fish oil moderately increases blood glucose and decreases insulin sensitivity in persons with type 2 diabetes without hypertriacylglycerolemia and alters carbohydrate and fat utilization in a time-dependent manner.     

Effects of marine n-3 fatty acid supplementation on lipoprotein subclasses measured by nuclear magnetic resonance in subjects with type II diabetes

OBJECTIVE: To measure effects of fish oil supplements on lipoprotein subclasses by nuclear magnetic resonance (NMR) in subjects with type II diabetes and relate them to insulin sensitivity. DESIGN: Two-armed, parallel, placebo-controlled, randomized. SUBJECTS: Normotriglyceridemic subjects with type II diabetes without insulin treatment were given either fish oil (n=12, median intake 5.9 g/day total n-3 fatty acids (FA) (1.8 g 20:5n-3, 3.0 g 22:6n-3)) or corn oil (n=14, 8.5 g/day 18:2n-6 FA). METHODS: Size and concentration of lipoproteins subclasses were measured by NMR, insulin sensitivity by hyperinsulinemic, isoglycemic clamps. RESULTS: After 9 weeks, there were differences between those treated with fish and corn oil with respect to very low-density lipoprotein (VLDL) size (median -15 vs +0.6%, P=0.001), particle concentrations of large VLDL (-99 vs -4.1%, P=0.041) and small high-density lipoprotein (HDL) (-12 vs +10%, P=0.051). Compared with corn oil fish oil tended to increase HDL size and small low-density lipoprotein (LDL) concentration (P=0.063 and 0.068, respectively, for differences between groups). There was no effect on oxidized LDL. Insulin sensitivity (glucose utilization) decreased in the fish oil group compared with the corn oil group (P=0.049). The decrease in insulin sensitivity did not correlate with the effects on lipoprotein subclasses. CONCLUSIONS: A high intake of n-3 FA exerts effects on several lipoprotein subclasses without obvious influence from changes in insulin sensitivity.     

The reliability of endtidal CO2 in spontaneously breathing children during anaesthesia with laryngeal mask airway,low flow,sevoflurane and caudal epidural

BACKGROUND: Noninvasive devices for monitoring endtidal CO2 (PECO2) are in common use in paediatric anaesthesia. Questions have been raised concerning the reliability of these devices in spontaneous breathing children during surgery. Our anaesthetic technique for elective infraumbilical surgery consists of spontaneous breathing through a Laryngeal Mask Airway (LMA), low fresh gas flow, sevoflurane and a caudal epidural. We wanted to compare PECO2 and arterial CO2 (PaCO2) during surgery. METHODS: Twenty children, aged 1-6 years, scheduled for infraumbilical surgery, were studied and one arterial sample was taken 45 min after induction of anaesthesia. PECO2, inspiratory PCO2, oxygen saturation, heart rate, respiratory rate, mean arterial blood pressure and expiratory sevoflurane concentration were measured every 5 min. The respiratory and circulatory parameters were stable during surgery. RESULTS: The mean PaCO2 - PECO2 difference was 0.15 (0.16) kPa [1.1 (1.2 mmHg)]. CONCLUSIONS: PECO2 is a good indicator of PaCO2 in our anaesthetic setting.     

Estimating the number of contributors to a DNA profile

The broad topic of this paper is the evaluation of DNA evidence in criminal cases. More specifically, we deal with mixture evidence which refers to cases where there are, or could be, several contributors to a biological stain based on, e.g., blood or semen. The present paper adresses DNA mixtures based on single nucleotide polymorphism (SNP) markers, i.e., diallelic markers. Based on STR analysis, it is in most cases easy to identify the presence of a mixture since three or four bands will show up with a high probability for at least one locus. Obviously, this will not be the case for diallelic markers and interpreting mixtures will be a great challenge. We address this problem by first approaching the more general problem of estimating the number of contributors to a stain. In addition we discuss how the markers should be selected and how many are required.     

Cervical shedding of herpes simplex virus and cytomegalovirus throughout the menstrual cycle in women infected with human immunodeficiency virus type 1

OBJECTIVE: Our purpose was to evaluate the frequency and patterns of the shedding of herpes simplex virus and cytomegalovirus in the female genital tract throughout the menstrual cycle. STUDY DESIGN: Seventeen women, all seropositive for herpes simplex virus types 1 and 2, cytomegalovirus, and human immunodeficiency virus type 1, underwent daily evaluation of cervical viral shedding for the duration of 1 menstrual cycle (21-31 visits per woman). Serum estradiol and progesterone levels were monitored 3 times weekly. RESULTS: Overall, herpes simplex virus deoxyribonucleic acid was detected in 43 (10%) of 450 cervical swabs, and cytomegalovirus deoxyribonucleic acid was detected in 232 (52%) of 450 cervical swabs. For individual women there was considerable variability in the percentage of days on which virus was detected, ranging from 0% to 33% for herpes simplex virus and from 20% to 97% for cytomegalovirus. Shedding of herpes simplex virus did not vary significantly with menstrual cycle; however, shedding of cytomegalovirus was significantly more frequent in the luteal phase (odds ratio, 1.9; 95% confidence interval, 1.1-3.4). A CD4(+) lymphocyte count <200/microL was associated with increased frequency of the detection of herpes simplex virus (odds ratio, 5.7; 95% confidence interval, 1.1-29.4). CONCLUSIONS: Asymptomatic cervical shedding of both herpes simplex virus and cytomegalovirus occurs very frequently in women infected with human immunodeficiency virus type 1. The risk of transmitting these viruses to sexual partners and neonates may be higher than previously recognized.     

High Mycoplasma genitalium organism burden is associated with shedding of HIV-1 DNA from the cervix

We assessed the relationship between infection with Mycoplasma genitalium, an emerging sexually transmitted pathogen, and cervical shedding of human immunodeficiency virus (HIV)-1 DNA among 303 HIV-1-positive Kenyan women. HIV-1 shedding was detected by qualitative polymerase chain reaction (PCR) in 154 women (51%); M. genitalium was detected by qualitative PCR in 52 (17%), and organism burden was determined by quantitative PCR. Women with high M. genitalium organism burdens (more than the median of 3195 genomes/mL) were 3-fold more likely to shed HIV-1 DNA than were M. genitalium-negative women (adjusted OR, 2.9 [95% confidence interval, 1.1-7.6]), yet this did not appear to be mediated by traditional measures of cervical inflammation (elevated polymorphonuclear leukocyte count).     

Effects of a 3‐day low‐fat diet on metabolic control,insulin sensitivity,lipids and adipocyte hormones in Norwegian subjects with hypertriacylglycerolaemia and type 2 diabetes

The metabolic and hormonal impact of rapid dietary changes in type 2 diabetes has not been clarified. The objective of this study was to test whether a short‐term, low‐fat diet affected metabolic control, insulin sensitivity, lipids and adipocyte hormones in patients with type 2 diabetes with hypertriacylglycerolaemia. Nineteen outpatient subjects (10 M, 9 F) with type 2 diabetes and triacylglycerols >2.2?mmol/L at screening were included in the study. Dietary intake was assessed by weighing during two periods of 3‐day baseline diet followed by a 3‐day low‐fat dietary intervention. The two periods of baseline diet did not differ with respect to relevant variables during intervention. Subjects were advised to increase fibre‐rich and low‐fat foods and to decrease intake of visible fat in an isoenergetic manner. The percentage of energy from fat was reduced from 39 to 22 (p<0.0001), median values. Daytime blood glucose did not change and fasting insulin and fasting glucose to insulin ratios were unaffected. Total cholesterol decreased from 6.3 to 6.2?mmol/L (p<0.005), high‐density lipoprotein cholesterol from 1.13 to 1.10?mmol/L (p<0.048) and the ratio of n‐6 to n‐3 fatty acids in phospholipids from 2.5 to 1.9 (p<0.003). Concentrations of leptin decreased from 12.1 to 9.9?ng/mL (p<0.005) and adiponectin increased from 8.6 to 10.5?μg/mL (p<0.024). The effect on leptin was confined to women. A low‐fat diet intervention for 3 days in insulin‐resistant type 2 diabetes affects lipid, adiponectin and leptin levels but fails to improve insulin sensitivity and metabolic control.     

A PILOT STUDY OF CORE STABILITY AND ATHLETIC PERFORMANCE: IS THERE A RELATIONSHIP?

Study Design:

Correlation study

Objectives:

To objectively evaluate the relationship between core stability and athletic performance measures in male and female collegiate athletes.

Background:

The relationship between core stability and athletic performance has yet to be quantified in the available literature. The current literature does not demonstrate whether or not core strength relates to functional performance. Questions remain regarding the most important components of core stability, the role of sport specificity, and the measurement of core stability in relation to athletic performance.

Methods:

A sample of 35 volunteer student athletes from Asbury College (NAIA Division II) provided informed consent. Participants performed a series of five tests: double leg lowering (core stability test), the forty yard dash, the T-test, vertical jump, and a medicine ball throw. Participants performed three trials of each test in a randomized order.

Results:

Correlations between the core stability test and each of the other four performance tests were determined using a General Linear Model. Medicine ball throw negatively correlated to the core stability test (r –0.389, p=0.023). Participants that performed better on the core stability test had a stronger negative correlation to the medicine ball throw (r =–0.527). Gender was the most strongly correlated variable to core strength, males with a mean measurement of double leg lowering of 47.43 degrees compared to females having a mean of 54.75 degrees.

Conclusions:

There appears to be a link between a core stability test and athletic performance tests; however, more research is needed to provide a definitive answer on the nature of this relationship. Ideally, specific performance tests will be able to better define and to examine relationships to core stability. Future studies should also seek to determine if there are specific sub-categories of core stability which are most important to allow for optimal training and performance for individual sports.