Reversing microcrystalline tests: an analytical approach to recycling of microcrystals from drugs of abuse

A combined analysis of microcrystalline tests followed by LC-MS or GC-MS analysis is described. Microcrystalline tests are shown to be non-destructive as addition products formed were easily dissociated after the application of an appropriate solvent. Subsequent analysis of the sample was done to quantify the recovery of the drug. Examples were performed using the date rape drug γ-hydroxybutyrate (GHB) and the synthetic opioid methadone

The effects of recombination rate on the distribution and abundance of transposable elements

Transposable elements (TEs) often accumulate in regions of the genome with suppressed recombination. But it is unclear whether this pattern reflects a reduction in the efficacy of selection against deleterious insertions or a relaxation of ectopic recombination. Discriminating between these two hypotheses has been difficult, because no formal model has investigated the effects of recombination under the deleterious insertion model. Here we take a simulation-based approach to analyze this scenario and determine the conditions under which element accumulation is expected in low recombination regions. We show that TEs become fixed as a result of Hill–Robertson effects in the form of Muller's ratchet, but only in regions of extremely low recombination when excision is effectively absent and synergism between elements is weak. These results have important implications for differentiating between the leading models of how selection acts on TEs and should help to interpret emerging population genetic and genomic data

Firm boundaries and financing with opportunistic stakeholder behaviour

We explore the impact of strategic behaviour of equity holders, debt holders and an opportunistic supplier of a critical input on the firm's capital structure, organisational design, and its outsourcing decision. We show that the supplier can trigger strategic bankruptcy even when the firm is solvent. Equity holders respond to this either by eliminating the supplier and producing the input in-house or by reducing their exposure to debt by using equity-financing. Both responses introduce inefficiency since input costs are higher with in-house production, and debt is cheaper than equity. We show that the equilibrium debt-equity ratio varies positively with cash-flow profitability and the marginal cost of the supplier's input, but negatively with the riskiness of the cash flow and the equity holders' in-house input production costs