Dataset of lithium-ion battery degradation based on a forklift mission profile for state-of-health estimation and lifetime prediction.

Lithium-ion (Li-ion) batteries are becoming an increasingly integral part of modern society, through consumer electronics, stabilisation of the electric grid, and electric vehicles. However, Lithium-ion batteries degrade in effectiveness over time; a degradation which is extremely dependent on the usage of the battery. Therefore, to study how a battery cell degrades under dynamic conditions, a realistic load profile was constructed based on the operation of forklifts. This profile was used to age three Lithium-ion battery cells at 45, 40, and 35°C and the response of the cells was measured on a second-by-second basis. Periodically the ageing was halted to perform a reference test of the cells allowing for the tracking of their degradation.

Modelling allelic drop-outs in STR sequencing data generated by MPS.

We used a Poisson-gamma model to analyse the allele coverage of autosomal short tandem repeat (STR) systems obtained by massively parallel sequencing (MPS). The Poisson-gamma coverage model was created using the peak height models from capillary electrophoresis (CE) based detection of PCR products as a starting point. The CE models were modified to account for the differences between CE and MPS signals by accounting for the large marker imbalances seen for MPS data and by using the Poisson-gamma distribution instead of the normal, log-normal, or gamma distributions that were applied for CE data. We took two approaches to estimate the marker imbalance parameters by (1) using a work-flow data base, and (2) using the results of replicate investigations of the samples. The Poisson-gamma model was used to estimate the rate of drop-outs of (1) single contributor dilution series experiments and (2) the minor contributor in two-person mixture samples. We examined the predictive capabilities of the model by comparing the observed and expected Brier scores of each sample. We derived the expected Brier scores and their variances to create asymptotic confidence intervals of the Brier scores. We found that the Poisson-gamma model performed well when using the work-flow data base, but that the replicate approach is not necessarily a viable option.

Stutter analysis of complex STR MPS data.

Stutters are common and well documented artefacts of amplification of short tandem repeat (STR) regions when using polymerase chain reaction (PCR) occurring as strands one or more motifs shorter or longer than the parental allele. Understanding the mechanism and rate by which stutters are created is especially important when the samples contain small amounts of DNA or DNA from multiple contributors. It has been shown that there is a linear relationship between the longest uninterrupted stretch (LUS) and the stutter ratio. This holds if there is only a single type of stutter variant. However, with massively parallel sequencing (MPS), we see that alleles may create different stutters corresponding to stuttering of different parts of the parental allele. This calls for a refinement of the LUS concept. We analysed all uninterrupted stretches, here called blocks, and identified the block from which the stutter originated. We defined the block length of the missing motif (BLMM) as the length of the identified block. We found that the relationship between the stutter ratio and BLMM was linear using a simple system of recurrence relations. We found that the mean square error decreased by a factor up to 17.5 for compound and complex autosomal markers when using BLMM instead of LUS.

Statistical modelling of Ion PGM HID STR 10-plex MPS data.

We investigated the results of short tandem repeat (STR) markers of dilution series experiments and reference profiles generated using the Ion PGM massively parallel sequencing platform utilising the HID STR 10-plex panel. The STR markers were identified by the marker specific flanking regions of the STR region. We investigated the following: (1) the usage of quality measures for identifying substitution errors, (2) the heterozygote balance and compared it to that of capillary electrophoresis (CE), (3) the stability of the coverage and the consequence of IonExpress Barcode adapter (IBA) sampling with decreasing amounts of template DNA, (4) the hypothesis that the parental longest uninterrupted stretch (LUS) is a better linear predictor of stutter ratio than the parent allele length, (5) the use of parental allele length as a predictor of shoulder ratio, and (6) the removal of non-systematic erroneous sequences using dynamic thresholds created by fitting the distribution of the non-systematic erroneous sequences. We found that, due to MID sampling, the average coverage on a marker could not be used as an apt predictor of the amount of template DNA. The parental LUS was shown to be better predictor of stutter ratio than the parental allele repeat length, when markers with compound and complex repeat patterns or markers which contained micro-variants were considered, such as marker TH01 showed R2 of 0.02 and 0.78 for parent allele repeat length and LUS, respectively. The one-inflated negative binomial method (OINB) and geometric model that can be used to remove non-systematic noise left on average 1.8 and 1.2 systematic errors per STR system, respectively.