Educating and Training Library Practitioners: A Comparative History with Trends and Recommendations

published or submitted for publicatio

Robust multi-year climate impacts of volcanic eruptions in decadal prediction systems

Major tropical volcanic eruptions have a large impact on climate, but there have only been three major eruptions during the recent relatively well-observed period. Models are therefore an important tool to understand and predict the impacts of an eruption. This study uses five state-of-the-art decadal prediction systems that have been initialized with the observed state before volcanic aerosols are introduced. The impact of the volcanic aerosols is found by subtracting the results of a reference experiment where the volcanic aerosols are omitted. We look for the robust impact across models and volcanoes by combining all the experiments, which helps reveal a signal even if it is weak in the models. The models used in this study simulate realistic levels of warming in the stratosphere, but zonal winds are weaker than the observations. As a consequence, models can produce a pattern similar to the North Atlantic Oscillation in the first winter following the eruption, but the response and impact on surface temperatures is weaker than in observations. Reproducing the pattern, but not the amplitude, may be related to a known model error. There are also impacts in the Pacific and Atlantic Oceans. This work contributes towards improving the interpretation of decadal predictions in the case of a future large tropical volcanic eruption

Dielectrophoresis of nanocolloids: a molecular dynamics study

Dielectrophoresis (DEP), the motion of polarizable particles in non-uniform electric fields, has become an important tool for the transport, separation, and characterization of microparticles in biomedical and nanoelectronics research. In this article we present, to our knowledge, the first molecular dynamics simulations of DEP of nanometer-sized colloidal particles. We introduce a simplified model for polarizable nanoparticles, consisting of a large charged macroion and oppositely charged microions, in an explicit solvent. The model is then used to study DEP motion of the particle at different combinations of temperature and electric field strength. In accord with linear response theory, the particle drift velocities are shown to be proportional to the DEP force. Analysis of the colloid DEP mobility shows a clear time dependence, demonstrating the variation of friction under non-equilibrium. The time dependence of the mobility further results in an apparent weak variation of the DEP displacements with temperature

Management Accounting & Academe

Management accounting offers rewarding research opportunities. If researchers are able to identify more efficient ways to analyze internal accounting data, these new methods can be adopted immediately by interested companies. Breakthroughs in management accounting research do not have to filter through a standard-setting body before they can have an impact on practice. Due to the absence of management accounting rules, the great demand for management accounting research, and the availability of management accounting data, it is not surprising that academic research is beginning to drive the field of management accounting

The Internal Control Paradox: What Every Manager Should Know

Examines some conflicting trends concerning internal control systems of companies in the 1990s. Definition of internal control; Trends toward internal control; Trends away from internal control; Balanced view of internal control; Solution to the internal control paradox

Examining reliability of seasonal to decadal sea surface temperature forecasts: the role of ensemble dispersion

Useful probabilistic climate forecasts on decadal timescales should be reliable (i.e. forecast probabilities match the observed relative frequencies) but this is seldom examined. This paper assesses a necessary condition for reliability, that the ratio of ensemble spread to forecast error being close to one, for seasonal to decadal sea surface temperature retrospective forecasts from the Met Office Decadal Prediction System (DePreSys). Factors which may affect reliability are diagnosed by comparing this spread-error ratio for an initial condition ensemble and two perturbed physics ensembles for initialized and uninitialized predictions. At lead times less than 2 years, the initialized ensembles tend to be under-dispersed, and hence produce overconfident and hence unreliable forecasts. For longer lead times, all three ensembles are predominantly over-dispersed. Such over-dispersion is primarily related to excessive inter-annual variability in the climate model. These findings highlight the need to carefully evaluate simulated variability in seasonal and decadal prediction systems.Useful probabilistic climate forecasts on decadal timescales should be reliable (i.e. forecast probabilities match the observed relative frequencies) but this is seldom examined. This paper assesses a necessary condition for reliability, that the ratio of ensemble spread to forecast error being close to one, for seasonal to decadal sea surface temperature retrospective forecasts from the Met Office Decadal Prediction System (DePreSys). Factors which may affect reliability are diagnosed by comparing this spread-error ratio for an initial condition ensemble and two perturbed physics ensembles for initialized and uninitialized predictions. At lead times less than 2 years, the initialized ensembles tend to be under-dispersed, and hence produce overconfident and hence unreliable forecasts. For longer lead times, all three ensembles are predominantly over-dispersed. Such over-dispersion is primarily related to excessive inter-annual variability in the climate model. These findings highlight the need to carefully evaluate simulated variability in seasonal and decadal prediction systems

Organizational Control Systems: Matching Controls with Organizational Levels

Companies today face a number of risks, such as environmental liabilities, losses from misuse of derivatives or harassment suits, which underscore the need for better control systems. Clearly, there is a tradeoff between having too much versus too little control. However, in addition to the amount of control, the mix of controls is important in maintaining the right balance within an organization. A framework is proposed that should help managers determine the appropriate matching of control types and control levels in their organizations. The matching is discussed for both traditional companies and modern, information-age companies

COSO: More Relevant Now than Ever

In 1992 when the Committee of Sponsoring Organizations of the Treadway Commission (COSO) issued its internal control framework, few would have guessed that the framework would become an integral part of corporate accountability a decade later, but things are moving in that direction. COSO\u27s framework may become an important tool for implementing the directives set forth in the Sarbanes-Oxley Act of 2002. With the newly mandated reporting on controls and other directives set forth in the Sarbanes-Oxley Act, the full effect of COSO\u27s internal control vision may finally be realized. COSO\u27s framework may help to address compliance with the new internal control reporting requirements. Although the primary focus of the COSO report is internal control, the framework has implications for other areas of the Sarbanes-Oxley Act as well

Fine structure of excitons in Cu2_2O

Three experimental observations on 1s-excitons in Cu$_2$O are not consistent with the picture of the exciton as a simple hydrogenic bound state: the energies of the 1s-excitons deviate from the Rydberg formula, the total exciton mass exceeds the sum of the electron and hole effective masses, and the triplet-state excitons lie above the singlet. Incorporating the band structure of the material, we calculate the corrections to this simple picture arising from the fact that the exciton Bohr radius is comparable to the lattice constant. By means of a self-consistent variational calculation of the total exciton mass as well as the ground-state energy of the singlet and the triplet-state excitons, we find excellent agreement with experiment.Comment: Revised abstract; 10 pages, revtex, 3 figures available from G. Kavoulakis, Physics Department, University of Illinois, Urban