Melanoma stem cells – are there devils in the detail?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79226/1/j.1755-148X.2010.00750.x.pd

"Disastrous Adoption"? Representations of Fetal Alcohol Syndrome and Disability in Recent Native North American Writing

Peer reviewe

Progress in understanding melanoma propagation

Melanoma, like most cancers, is a disease that wreaks havoc mostly through its propensity to spread and establish secondary tumors at sites that are anatomically distant from the primary tumor. The consideration of models of cancer progression is therefore important to understand the essence of this disease. Previous work has suggested that melanoma may propagate according to a cancer stem cell (CSC) model in which rare tumorigenic and bulk non‐tumorigenic cells are organized into stable hierarchies within tumors. However, recent studies using assays that are more permissive for revealing tumorigenic potential indicate that it will not be possible to cure patients by focusing research and therapy on rare populations of cells within melanoma tumors. Studies of the nature of tumorigenic melanoma cells reveal that these cells may gain a growth, metastasis and/or therapy resistance advantage by acquiring new genetic mutations and by reversible epigenetic mechanisms. In this light, efforts to link the phenotypes, genotypes and epigenotypes of melanoma cells with differences in their in vivo malignant potential provide the greatest hope of advancing the exciting progress finally being made against this disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135709/1/mol2201045451.pd

Continuous Workout Mortgages

This paper models Continuous Workout Mortgages (CWMs) in an economic environment with refinancings and prepayments by employing a market-observable variable such as the house price index of the pertaining locality. Our main results include: (a) explicit modelling of repayment and interest-only CWMs; (b) closed form formulae for mortgage payment and mortgage balance of a repayment CWM; (c) a closed form formula for the actuarially fair mortgage rate of an interest-only CWM. For repayment CWMs we extend our analysis to include two negotiable parameters: adjustable "workout proportion" and adjustable "workout threshold." These results are of importance as they not only help understanding the mechanics of CWMs and estimating key contract parameters. These results are of importance as they not only help in the understanding of the mechanics of CWMs and estimating key contract parameters, but they also provide guidance on how to enhance the resilience of the financial architecture and mitigate systemic risk.Continuous Workout Mortgage (CWM), Repayment, Interest-only, House price index, Prepayment intensity, Cap and floor on continuous flow

Option-Implied Volatilities and Stock Returns: <i>Evidence from Industry-Neutral Portfolios</i>

Recent studies demonstrate the profitability of stock portfolios constructed according to implied volatility measures inferred from option prices. This article examines industry effects on such portfolios’ performance. Results show that quintile portfolios constructed using volatility skew and volatility spread are subject to substantial industry effects, which are particularly strong during market turbulence. The authors form industry-neutral portfolios and compare their performances to those of full-universe portfolios that do not consider industry exposure. Results show significant improvement when portfolio strategies are implemented in an industry-neutral manner, based on either volatility skew or volatility spread

Buyback behaviour and the option funding hypothesis

We study how stock option grants are funded through share repurchases under conditions of option exercisability and moneyness. Using daily repurchase disclosures by U.K. firms, we corroborate our hypothesis that driven by flexibility, firms repurchase early in an option schedule while options are out-of-money and before becoming exercisable. Our findings show that when daily stock prices are below weighted average option exercise price and when options are not immediatelyexercisable, firms(a)increasedailyrepurchasevolume(value), (b)increase repurchase frequency, and (c) have lower relative repurchase prices. We further evidence this by examining the change in treasury regulation that enabled firms to hold on to repurchased shares rather than cancelling them. Our findings show a strong support for option funding motives in the post-treasury regulation period when repurchase flexibility is greater

Continuous Workout Mortgages

This paper models Continuous Workout Mortgages (CWMs) in an economic environment with refinancings and prepayments by employing a market-observable variable such as the house price index of the pertaining locality. Our main results include: (a) explicit modelling of repayment and interest-only CWMs; (b) closed form formulae for mortgage payment and mortgage balance of a repayment CWM; (c) a closed form formula for the actuarially fair mortgage rate of an interest-only CWM. For repayment CWMs we extend our analysis to include two negotiable parameters: adjustable “workout proportion” and adjustable “workout threshold.” These results are of importance as they not only help understanding the mechanics of CWMs and estimating key contract parameters. These results are of importance as they not only help in the understanding of the mechanics of CWMs and estimating key contract parameters, but they also provide guidance on how to enhance the resilience of the financial architecture and mitigate systemic risk

Essays in Factor Investing

This thesis advances the theory and practice of factor investing by exploring the rich set of developed factors to explain portfolio performances in the equity and multi-asset space. Chapter 1 characterizes the strong performance of equal-weighted (EW) portfolios in relation to their value-weighted counterparts by utilizing various factor models. Unsurprisingly, EW investing comes with a highly significant positive size factor exposure but is also found to benefit from short-term reversal effects while suffering from negative momentum exposure due to its acyclic rebalancing character. Given that EW investing effectively emerges as factor investing in disguise, it seems natural to adopt a direct factor investing approach. To this end, the literature has proposed a multitude of firm characteristics for explaining the cross-section of stock returns, yet Chapter 2 demonstrates only about 15 factors to be relevant for spanning the entire factor zoo from an alpha perspective. Whilst these salient factors change through time, they fall into persistent factor style categories. Further broadening the scope, the thesis moves on to explain the cross-section of asset classes through a macro factor lens. Specifically, Chapter 3 investigates macroeconomic factor allocation based on macro factor-mimicking portfolios that consider style factors and individual asset classes alike. Chapter 4 investigates such macro factor investing over a century of data, demonstrating it to be robust in different economic regimes. Incorporating business cycle-based macro and style factor views in a Black-Litterman fashion we additionally accommodate the notion of factor timing to improve upon a diversified macro factor risk-parity strategy