Probabilistic expert systems for handling artifacts in complex DNA mixtures

This paper presents a coherent probabilistic framework for taking account of allelic dropout, stutter bands and silent alleles when interpreting STR DNA profiles from a mixture sample using peak size information arising from a PCR analysis. This information can be exploited for evaluating the evidential strength for a hypothesis that DNA from a particular person is present in the mixture. It extends an earlier Bayesian network approach that ignored such artifacts. We illustrate the use of the extended network on a published casework example

Identification and separation of DNA mixtures using peak area information (Updated version of Statistical Research Paper No. 25)

We introduce a new methodology, based upon probabilistic expert systems, for analysing forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for ascertaining whether individuals, whose profiles have been measured, have contributed to the mixture, but also to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our probabilistic methodology is illustrated on case data examples and compared with alternative approaches. The advantages are that identification and separation issues can be handled in a unified way within a single probabilistic model and the uncertainty associated with the analysis is quantified. Further work, required to bring the methodology to a point where it could be applied to the routine analysis of casework, is discussed

Observations of fertilizer absorption of atmospheric water

Non-Peer ReviewedFertilize salts are subject to adsorption of atmospheric water plus condensation of water within fertilizer handling systems and fertilizer applicators. This can lead to significant problems in both application and safe handling of fertilizers. This paper will provide a visual overview of the impact of water absorption of various fertilizer products and fertilizer blends

GEOCHEMICAL IMPLICATIONS OF GYPSUM ADDITION TO OIL SANDS FLUID FINE TAILINGS: LABORATORY BATCH AND COLUMN EXPERIMENTS

Large inventories of tailings in the Alberta Oil Sands have created the need for technologies that can accelerate dewatering of fluid tailings; however, knowledge of long-term implications from these technologies is limited. This research was split into two studies, examining: 1) temporal changes in porewater chemistry and gas production in gypsum-amended Fluid Fine Tailings (FFT), and 2) temporal and spatial changes in porewater chemistry in Centrifuged Fine Tailings (CFT) during successive freeze-thaw-evaporation cycles. An anoxic laboratory batch experiment was conducted, where differing gypsum amendments were added to FFT, and destructively sampled over 64 weeks. Methane measured in the headspace showed inconclusive results for the effect of gypsum on methanogenesis. Gypsum-amended FFT showed an increase in dissolved salts, with Na increasing up to 1.3 times (820–1,100 mg L−1) and Mg increasing up to 4.2 times (9.55–39.9 mg L−1) compared to the control. In the second experiment, six columns filled with CFT were subjected to three consecutive freeze thaw evaporation cycles, and sacrificially sampled before each thaw and evaporative period. Column mass decreased an average total of 28.5 kg with 72% of this attributed to runoff following the first thaw period. After this time, dissolved salts began accumulating in near the CFT surface, with Cl increasing up to 5.8 times (379–2,200 mg L−1), Na increasing up to 6.9 times (772–5,353 mg L−1), K increasing up to 15.6 times (16.1–251 mg L−1), and Mg increasing up to 94 times (22.0–2,069 mg L−1) compared to the initial CFT. Both studies revealed elevated porewater salt concentrations in gypsum-amended tailings, which could pose challenges for long-term reclamation of the oil sands tailings

Spontaneous ignition delay characteristics of hydrocarbon fuel-air mixtures

The influence of pressure on the autoignition characteristics of homogeneous mixtures of hydrocarbon fuels in air is examined. Autoignition delay times are measured for propane, ethylene, methane, and acetylene in a continuous flow apparatus featuring a multi-point fuel injector. Results are presented for mixture temperatures from 670K to 1020K, pressures from 1 to 10 atmospheres, equivalence ratios from 0.2 to 0.7, and velocities from 5 to 30 m/s. Delay time is related to pressure, temperature, and fuel concentration by global reaction theory. The results show variations in global activation energy from 25 to 38 kcal/kg-mol, pressure exponents from 0.66 to 1.21, and fuel concentration exponents from 0.19 to 0.75 for the fuels studied. These results are generally in good agreement with previous studies carried out under similar conditions

Sulphur fertilizers for alfalfa

Non-Peer Reviewe

The IIMI style manual

Documentation / Technical writing / Standards / Irrigation management / Computers / English language

Worker Choices About Payouts in Public Pensions

The paper will review available data on the annuity choices offered to retirees who participate in defined benefit (DB) plans. DB plans are most commonly offered by state and local governments to their employees, and information on annuity options is readily available. We will examine all state pension plans that cover general state employees and teachers, and we will develop a table showing the similarities and differences across these approximately 80 separate state retirement plans. We will contact the managers of a subset of these plans and request information on the proportion of retirees selecting each of the annuity options. Where possible, we will compare annuity options in the public sector to those offered by private sector employers. The paper will also include a review of the empirical literature on who chooses the various annuity options offered in DB plans. Finally, we will consider the policy implications of plan design and how this affects the types of annuities offered to retirees

Waist-to-height ratio and cardiometabolic risk factors in adolescence: findings from a prospective birth cohort

What is already known about this subject In adults, associations between body mass index (BMI), waist-to-height ratio (WHtR) and cardiometabolic outcomes are similar. In children and adolescents, results from cross-sectional studies examining the associations between BMI z scores, WHtR and cardiometabolic outcomes are conflicting and there is a paucity of prospective data.<p></p> What this study adds This is the first study to demonstrate the prospective association between WHtR in childhood and cardiometabolic outcomes in adolescent boys. WHtR is a simple calculation that can be used to identify children and adolescents for cardiometabolic risk without the need for reference growth charts. The WHtR cut-point of ≥0.5 was highly specific in identifying cardiometabolic risk co-occurrence but has poor sensitivity.<p></p> Objective To examine the associations between body mass index (BMI) and waist-to-height ratio (WHtR) measured in childhood and adolescence and cardiometabolic risk factors in adolescence.<p></p> Methods Secondary data analysis of the Avon Longitudinal Study of Parents and Children, a population based cohort. Data from 2858 adolescents aged 15.5 (standard deviation 0.4) years and 2710 of these participants as children aged 7–9 years were used in this analysis. Outcome measures were cardiometabolic risk factors, including triglycerides, low density lipoprotein cholesterol, high density lipoprotein cholesterol, insulin, glucose and blood pressure at 15 years of age.<p></p> Results Both BMI and WHtR measured at ages 7–9 years and at age 15 years were associated with cardiometabolic risk factors in adolescents. A WHtR ≥0.5 at 7–9 years increased the odds by 4.6 [95% confidence interval 2.6 to 8.1] for males and 1.6 [0.7 to 3.9] for females of having three or more cardiometabolic risk factors in adolescence. Cross-sectional analysis indicated that adolescents who had a WHtR ≥0.5, the odds ratio of having three or more cardiometabolic risk factors was 6.8 [4.4 to 10.6] for males and 3.8 [2.3 to 6.3] for females. The WHtR cut-point was highly specific in identifying cardiometabolic risk co-occurrence in male children and adolescents as well as female children (90 to 95%), but had poor sensitivity (17 to 53%). Similar associations were observed when BMI was used to define excess adiposity.<p></p> Conclusions WHtR is a simple alternative to age and sex adjusted BMI for assessing cardiometabolic risk in adolescents