Memory of recessions.

This paper reviews the evidence on the effects of recessions on potential output. In contrast to the assumption in mainstream macroeconomic models that economic fluctuations do not change potential output paths, the evidence is that they do in the case of recessions. A model is proposed to explain this phenomenon, based on an analogy with water flows inporous media. Because of the discrete adjustments made by heterogeneous economic agents in such a world, potential output displays hysteresis with regard to aggregate demand shocks, and thus retains a memory of the shocks associated with recessions.Recessions, Permanent Effects, Hydraulic Keynesianism, Porous Media, Hysteresis.

Hysteresis in the fundamentals of macroeconomics.

Two fundamental problems in economic analysis concern the determination of aggregate output, and the determination of market prices and quantities. The way economic adjustments are made at the micro level suggests that the history of shocks to the economic environment matters. This paper presents tractable approach for introducing hysteresis into models of how aggregate output and market prices and quantities are determined.Hysteresis, Aggregate Output, Market Supply and Demand

The Focas Institute at DIT : Origins and Development of a Research Institute

The book outlines the roots and development of a new scientific research institute called the Focas ( facility for Optical Characterisation and Spectroscopy) within the Dublin Institute of Technology

Vibrational Coupling in Conjugated π Systems with a view to Optimization of Fluorescence Yield through Phonon Confinement

A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Stokes shift also exhibited a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length. This correlation is further examined using Raman spectroscopy, whereby the integrated Raman scattering is seen to behave superlinearly with chain length. There is a clear indication that the vibrational activity and thus nonradiative decay processes are controllable through molecular structure. The correlations between the Stokes energies and the vibrational structure are also observed in a selection of PPV based polymers and a clear trend of increasing luminescence efficiency with decreasing vibrational activity and Stokes shift is observable. The implications of such structure property relationships in terms of materials design are discussed

Interaction of Carbon Nanotubes with Sugar Complexes

The interaction of carbon nanotubes with soft organic molecules such as cyclodextrins and other saccarides has recently been shown to produce water soluble composites. Such systems offer considerable advantages over polymer based composites due to their biocompatibility and noncovalent coupling which can potentially preserve the unique properties of the tubes. The mechanism of interaction for such systems has been proposed to be dominated by hydrophobic and hydrophilic interactions along the surface of the tube. However efforts to characterise and rationalise such noncovalent interactions between the sugar-based materials and the carbon nanotubes have been slow to emerge. In this study a composite system has been formed using HiPco Single Walled Carbon Nanotubes (HCNT) and starch (extracted from rice). This composite was characterised using a range of spectroscopic techniques, which showed clear evidence of an intermolecular interaction between the HCNT and starch. The characterisation of these systems will be presented and evidence to support the notion of a noncovalent interaction is clear

Memory of Recessions

This paper reviews the evidence on the effects of recessions on potential output. In contrast to the assumption in mainstream macroeconomic models that economic fluctuations do not change potential output paths, the evidence is that they do in the case of recessions. A model is proposed to explain this phenomenon, based on an analogy with water flows in porous media. Because of the discrete adjustments made by heterogeneous economic agents in such a world, potential output displays hysteresis with regard to aggregate demand shocks, and thus retains a memory of the shocks associated with recessions

Hysteresis in the Fundamentals of Macroeconomics

Two fundamental problems in economic analysis concern the determination of aggregate output, and the determination of market prices and quantities. The way economic adjustments are made at the micro level suggests that the history of shocks to the economic environment matters. This paper presents tractable approach for introducing hysteresis into models of how aggregate output and market prices and quantities are determined

Risk-averse foraging in bees: a comment on the model of harder and real

Within foraging theory, it has been common to take the reward currency to be the net amount of energy that is gained. Some care is needed in defining risk-sensitive foraging in this context. Where there is only one choice between two feeding options and each option takes the same amount of time to exploit, then it is reasonable to define an animal to be risk sensitive in reward magnitude if both the mean and the variance in energy gained influence preference

Long-term morbidity and mortality following bloodstream infection: a systematic literature review

Bloodstream infection results in significant short-term morbidity and mortality. No literature review has studied the long-term outcome following a bloodstream infection. This PROSPERO registered systematic review evaluated studies, which measured the association of a bloodstream infection with long-term morbidity and mortality.Databases were systematically searched for studies of adult patients reporting morbidity and/or mortality one year or more following a bloodstream infection in comparison to a matched cohort without a bloodstream infection.Ten observational studies were included in the final analysis. Five studies assessed only mortality, two assessed morbidity and mortality and three studies assessed morbidity only. The one year mortality ranged from between 8 and 48% for patients with bloodstream infection. The pooled risk ratio of death at one year was significantly higher for patients with bloodstream infection when compared to the matched cohort (RR 4.04 [95% CI 1.84-8.87]).Bloodstream infection was associated with poor long-term outcome measured at one year when compared to matched controls. More evidence is needed to determine if this association is causative