Treatment for depression following mild traumatic brain injury in adults: A meta-analysis

Primary objective: Development of depression after TBI is linked to poorer outcomes. The aim of this manuscript is to review evidence for the effectiveness of current treatments. Research design: Two meta-analyses were undertaken to examine the effectiveness of both pharmacological and non-pharmacological interventions for depression after mild TBI Method and procedures: PubMed, Medline, PsychInfo, Web of Science and Digital Dissertations were searched and 13 studies located. Meta Analyst Beta 3.13 was used to conduct analyses of pre- vs post-effects then to examine treatment group vs control group effects. Main outcomes and results: Studies using a pre–post design produced an overall effect size of 1.89 (95% CI = 1.20–2.58, p < 0.001), suggesting that treatments were effective; however, the overall effect for controlled trials was 0.46 (95% CI = −0.44–1.36, p < 0.001), which favoured the control rather than treatment groups. Conclusions: This study highlights the need for additional large well-controlled trials of effective treatments for depression post-TBI

The Integration of Connectionism and First-Order Knowledge Representation and Reasoning as a Challenge for Artificial Intelligence

Intelligent systems based on first-order logic on the one hand, and on artificial neural networks (also called connectionist systems) on the other, differ substantially. It would be very desirable to combine the robust neural networking machinery with symbolic knowledge representation and reasoning paradigms like logic programming in such a way that the strengths of either paradigm will be retained. Current state-of-the-art research, however, fails by far to achieve this ultimate goal. As one of the main obstacles to be overcome we perceive the question how symbolic knowledge can be encoded by means of connectionist systems: Satisfactory answers to this will naturally lead the way to knowledge extraction algorithms and to integrated neural-symbolic systems.Comment: In Proceedings of INFORMATION'2004, Tokyo, Japan, to appear. 12 page

L\'evy-type diffusion on one-dimensional directed Cantor Graphs

L\'evy-type walks with correlated jumps, induced by the topology of the medium, are studied on a class of one-dimensional deterministic graphs built from generalized Cantor and Smith-Volterra-Cantor sets. The particle performs a standard random walk on the sets but is also allowed to move ballistically throughout the empty regions. Using scaling relations and the mapping onto the electric network problem, we obtain the exact values of the scaling exponents for the asymptotic return probability, the resistivity and the mean square displacement as a function of the topological parameters of the sets. Interestingly, the systems undergoes a transition from superdiffusive to diffusive behavior as a function of the filling of the fractal. The deterministic topology also allows us to discuss the importance of the choice of the initial condition. In particular, we demonstrate that local and average measurements can display different asymptotic behavior. The analytic results are compared with the numerical solution of the master equation of the process.Comment: 9 pages, 9 figure

Sovereign credit ratings and their impact on recent financial crises

This paper discusses the role of the credit rating agencies during the recent financial crises. In particular, it examines whether the agencies can add to the dynamics of emerging market crises. Academics and investors often argue that sovereign credit ratings are responsible for pronounced boom-bust cycles in emerging-markets lending. Using a vector autoregressive system this paper examines how US dollar bond yield spreads and the short-term international liquidity position react to an unexpected sovereign credit rating change. Contrary to common belief and previous studies, the empirical results suggest that an abrupt downgrade does not necessarily intensify a financial crisis

The adjustment of credit ratings of defaulted issuers

We provide insights into determinants of the rating level of 371 issuers which defaulted in the years 1999 to 2003, and into the leader-follower relationship between Moody’s and S&P. The evidence for the rating level suggests that Moody’s assigns lower ratings than S&P for all observed periods before the default event. Furthermore, we observe two-way Granger causal-ity, which signifies information flow between the two rating agencies. Since lagged rating changes influence the magnitude of the agencies’ own rating changes it would appear that the two rating agencies apply a policy of taking a severe downgrade through several mild down-grades. Further, our analysis of rating changes shows that issuers with headquarters in the US are less sharply downgraded than non-US issuers. For rating changes by Moody’s we also find that larger issuers seem to be downgraded less severely than smaller issuers

Macroecology of methane-oxidizing bacteria: the β-diversity of pmoA genotypes in tropical and subtropical rice paddies

Studies addressing microbial biogeography have increased during the past decade, but research on microbial distribution patterns is still in its infancies, and many aspects are only poorly understood. Here, we compared the methanotroph community in paddy soils sampled in Indonesia, Vietnam, China and Italy, focusing on the distance-decay relationship. We used the pmoA gene as marker for methanotroph diversity in terminal restriction fragment length polymorphism, microarray and pyrosequencing approaches. We could observe a significant increase of -diversity with geographical distance across continents (12000km). Measured environmental parameters explained only a small amount of data variation, and we found no evidence for dispersal limitation. Thus, we propose historical contingencies being responsible for the observed patterns. Furthermore, we performed an in-depth analysis of type II methanotroph pmoA distribution at the sequence level. We used ordination analysis to project sequence dissimilarities into a three-dimensional space (multidimensional scaling). The ordination suggests that type II methanotrophs in paddy fields can be divided into five major groups. However, these groups were found to be distributed in all soils independent of the geographic origin. By including tropical field sites (Indonesia and Vietnam) into the analysis, we further observed the first paddy fields harbouring a methanotroph community depleted in type II methanotrophs

Heterogeneity in the Relationship between Disinfection By-Products in Drinking Water and Cancer: A Systematic Review.

The epidemiological evidence demonstrating the effect of disinfection by-products (DBPs) from drinking water on colon and rectal cancers is well documented. However, no systematic assessment has been conducted to assess the potential effect measure modification (EMM) in the relationship between DBPs and cancer. The objective of this paper is to conduct a systematic literature review to determine the extent to which EMM has been assessed in the relationship between DBPs in drinking water in past epidemiological studies. Selected articles (n = 19) were reviewed, and effect estimates and covariates that could have been used in an EMM assessment were gathered. Approximately half of the studies assess EMM (n = 10), but the majority of studies only estimate it relative to sex subgroups (n = 6 for bladder cancer and n = 2 both for rectal and colon cancers). Although EMM is rarely assessed, several variables that could have a potential modification effect are routinely collected in these studies, such as socioeconomic status or age. The role of environmental exposures through drinking water can play an important role and contribute to cancer disparities. We encourage a systematic use of subgroup analysis to understand which populations or territories are more vulnerable to the health impacts of DBPs

The covarion model of molecular evolution : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Biology at Massey University

Current methods for constructing evolutionary trees generally do not work well for sequences in which multiple substitutions have occurred. The covarion hypothesis may provide a solution to this problem. This hypothesis states that only a limited number of the codons in a given sequence are free to vary, but that the set of variable codons may change as mutations are fixed in the population. Although this is reasonable from a biological point of view, it is a difficult hypothesis to test scientifically because the apparent large number of parameters involved makes it very hard to analyse statistically. In this study, computer simulations were carried out on up to 51 machines running in parallel, using a simple covarion model based on a hidden Markov model (HMM) approach. This model required two new parameters—the proportion of sites that are variable at any given time, and the rate of exchange between fixed and variable states. These two parameters were both varied in the simulations. Sequence and distance data were simulated on a given tree under this covarion model, and these data were used to test the performance of standard tree-building methods at recovering the original tree The neighbour joining and maximum likelihood methods tested were found to perform better with data generated under the covarion model than with data generated under a simpler model in which all sites vary at the same rate. This suggests that current tree-building methods may perform better with biological data than computer simulation studies suggest

Counterparty credit risk management in industrial corporates

Ever since the financial crisis of the banking system of 2008 - 2010 the paradigm that deposits or other exposures towards major banks are safe has been fundamentally questioned. This put industrial corporates, who to support their business usually need to manage significant cash holdings or incur counterparty credit risk via derivatives, in the situation to develop or extend their resources for counterparty credit risk management. This paper provides a comprehensive overview over the practical issues into the subject benefitting largely from the findings of an interview series conducted with the respective heads of counterparty and customer credit risk management in the time period April - September 2011 of 25 large european enterprises with a large subset being members of the German DAX Index.Financial Risk Management; Credit Risk; Counterparty Credit Risk; CCR Management; Organisation; Financial Controlling; Financial Institutions; Banks