An artificial hormone system for self-organization of networked nodes

The rising complexity of distributed computer systems give reason to investigate self-organization mechanism to build systems that are self-managing in the sense of Autonomic and Organic Computing. In this paper we propose the Artificial Hormone System (AHS) as a general approach to build self-organizing systems based on networked nodes. The Artificial Hormone System implements a similar information exchange between networked nodes like the human hormone system does between cells. The artificial hormone values are piggy-backed on messages to minimize communication overhead. To show the efficiency of the mechanism even for large scale systems we implemented a simulation environment in Java to evaluate different optimization strategies. The evaluations show that local information is enough to meet global optimization criterion.1st IFIP International Conference on Biologically Inspired Cooperative Computing - Biological Inspiration 2Red de Universidades con Carreras en Informática (RedUNCI

An artificial hormone system for self-organization of networked nodes

The rising complexity of distributed computer systems give reason to investigate self-organization mechanism to build systems that are self-managing in the sense of Autonomic and Organic Computing. In this paper we propose the Artificial Hormone System (AHS) as a general approach to build self-organizing systems based on networked nodes. The Artificial Hormone System implements a similar information exchange between networked nodes like the human hormone system does between cells. The artificial hormone values are piggy-backed on messages to minimize communication overhead. To show the efficiency of the mechanism even for large scale systems we implemented a simulation environment in Java to evaluate different optimization strategies. The evaluations show that local information is enough to meet global optimization criterion.1st IFIP International Conference on Biologically Inspired Cooperative Computing - Biological Inspiration 2Red de Universidades con Carreras en Informática (RedUNCI

Dissecting grain yield pathways and their interactions with grain dry matter content by a two-step correlation approach with maize seedling transcriptome

<p>Abstract</p> <p>Background</p> <p>The importance of maize for human and animal nutrition, but also as a source for bio-energy is rapidly increasing. Maize yield is a quantitative trait controlled by many genes with small effects, spread throughout the genome. The precise location of the genes and the identity of the gene networks underlying maize grain yield is unknown. The objective of our study was to contribute to the knowledge of these genes and gene networks by transcription profiling with microarrays.</p> <p>Results</p> <p>We assessed the grain yield and grain dry matter content (an indicator for early maturity) of 98 maize hybrids in multi-environment field trials. The gene expression in seedlings of the parental inbred lines, which have four different genetic backgrounds, was assessed with genome-scale oligonucleotide arrays. We identified genes associated with grain yield and grain dry matter content using a newly developed two-step correlation approach and found overlapping gene networks for both traits. The underlying metabolic pathways and biological processes were elucidated. Genes involved in sucrose degradation and glycolysis, as well as genes involved in cell expansion and endocycle were found to be associated with grain yield.</p> <p>Conclusions</p> <p>Our results indicate that the capability of providing energy and substrates, as well as expanding the cell at the seedling stage, highly influences the grain yield of hybrids. Knowledge of these genes underlying grain yield in maize can contribute to the development of new high yielding varieties.</p

Recursive Definitions of Monadic Functions

Using standard domain-theoretic fixed-points, we present an approach for defining recursive functions that are formulated in monadic style. The method works both in the simple option monad and the state-exception monad of Isabelle/HOL's imperative programming extension, which results in a convenient definition principle for imperative programs, which were previously hard to define. For such monadic functions, the recursion equation can always be derived without preconditions, even if the function is partial. The construction is easy to automate, and convenient induction principles can be derived automatically.Comment: In Proceedings PAR 2010, arXiv:1012.455

Influence of Stimulant Medication and Response Speed on Lateralization of Movement-Related Potentials in Attention-Deficit/Hyperactivity Disorder

Hyperactivity is one of the core symptoms in attention deficit hyperactivity disorder (ADHD). However, it remains unclear in which way the motor system itself and its development are affected by the disorder. Movement-related potentials (MRP) can separate different stages of movement execution, from the programming of a movement to motor post-processing and memory traces. Pre-movement MRP are absent or positive during early childhood and display a developmental increase of negativity. We examined the influences of response-speed, an indicator of the level of attention, and stimulant medication on lateralized MRP in 16 children with combined type ADHD compared to 20 matched healthy controls. We detected a significantly diminished lateralisation of MRP over the pre-motor and primary motor cortex during movement execution (initial motor potential peak, iMP) in patients with ADHD. Fast reactions (indicating increased visuo-motor attention) led to increased lateralized negativity during movement execution only in healthy controls, while in children with ADHD faster reaction times were associated with more positive amplitudes. Even though stimulant medication had some effect on attenuating group differences in lateralized MRP, this effect was insufficient to normalize lateralized iMP amplitudes.A reduced focal (lateralized) motor cortex activation during the command to muscle contraction points towards an immature motor system and a maturation delay of the (pre-) motor cortex in children with ADHD. A delayed maturation of the neuronal circuitry, which involves primary motor cortex, may contribute to ADHD pathophysiology

It’s the tail-risk, stupid! : precluding regulatory arbitrage in shadow banking with a normatively charged approach to supervision capitalizing on multipolar regulatory dialogues

The use of contractual engineering to create channels of credit intermediation outside of the realm of banking regulation has been a recurring activity in Western financial systems over the last 50 years. After the financial crisis of 2007 and 2008, this phenomenon, at that time commonly referred to as ‘shadow banking’, evoked a large-scale regulatory backlash, including several specific regulatory constraints being placed on non-bank financial institutions (NBFI). This paper proposes a different avenue for regulators to keep regulatory arbitrage under control and preserve sufficient space for efficient financial innovation. Rather than engaging in the proverbial race between hare and hedgehog that is emerging with increasingly specific regulation of particular contractual arrangements, this paper argues for a normative approach to supervision. We outline this approach in detail by showing that regulators should primarily analyse the allocation of tail risk inherent in the respective contractual arrangements. Our paper proposes to assign regulatory burdens equivalent to prudential banking regulation, in case these arrangements become only viable through indirect or direct access to an (ad hoc) public backstop. In order to make the pivotal assessment, regulators will need information about recent contractual innovations and their risk-allocating characteristics. According to the scholarship on regulatory networks serving as communities of interpretation, we suggest in particular how regulators should structure their relationships with semi-public gatekeepers such as lawyers, auditors and consultants to keep abreast of the real-world implications of evolving transactional structures. This paper then uses the rise of credit funds as a non-bank entities economically engaged in credit intermediation to apply this normative framework, pointing to recent contractual innovations that call for more regulatory scrutiny in a multipolar regulatory dialogue

The case for a normatively charged approach to regulating shadow banking : multipolar regulatory dialogues as a means to detect tail risks and preclude regulatory arbitrage

This paper contributes to the debate on the adequate regulatory treatment of non-bank financial intermediation (NBFI). It proposes an avenue for regulators to keep regulatory arbitrage under control and preserve sufficient space for efficient financial innovation at the same time. We argue for a normative approach to supervision that can overcome the proverbial race between hare and hedgehog in financial regulation and demonstrate how such an approach can be implemented in practice. We first show that regulators should primarily analyse the allocation of tail risk inherent in NBFI. Our paper proposes to apply regulatory burdens equivalent to prudential banking regulation if the respective transactional structures become only viable through indirect or direct access to (ad hoc) public backstops. Second, we use insights from the scholarship on regulatory networks as communities of interpretation to demonstrate how regulators can retrieve the information on transactional innovations and their risk-allocating characteristics that they need to make the pivotal determination. We suggest in particular how supervisors should structure their relationships with semi-public gatekeepers such as lawyers, auditors and consultants to keep abreast of the risk-allocating features of evolving transactional structures. Finally, this paper uses the example of credit funds as non-bank entities economically engaged in credit intermediation to illustrate the merits of the proposed normative framework and to highlight that multipolar regulatory dialogues are needed to shed light on the specific risk-allocating characteristics of recent contractual innovations