Lincoln and McClellan: The Troubled Partnership Between a President and His General

Re-examining a Tested Relationship John Waugh’s Lincoln and McClellan is a study in a troubled relationship with the future of the United States at stake. Despite his strong dislike of his commander-in-chief Abraham Lincoln, Union General George B. McClellan plotted military stra...

Shrewd Abraham: Historians Assay Lincoln\u27s Public Image, Impact, And Martyrdom

The superb essays in Lincoln and His Contemporaries were developed from the Centennial Lincoln Symposium at Lincoln Memorial University in April 1997. Edited by Charles Hubbard, executive director of that institution\u27s Abraham Lincoln Museum, the book apprises both Civil War scholar and buff ...

The Coevolution of Platform Dominance and Governance Strategies: Effects on Complementor Performance Outcomes

Multisided platforms such as Apple’s App Store and Valve’s Steam become increasingly dominant when more end users and complement producers join their ecosystems. Despite their importance to a platform’s overall success, however, we know little about complement producers and how they are affected by a platform’s dominance trajectory: How does a platform’s increasingly dominant market position affect performance outcomes for complementors? We explore this question by conducting a multiple case study on four market leading platform ecosystems over several years. We discover that, as a platform becomes increasingly dominant, the platform sponsor’s governance strategies shift from being largely supportive of the wider complement population to becoming more selective and geared toward end users. These changes are associated with shifts in complementor performance outcomes. Although the value created at the overall ecosystem level increases as a platform gains dominance, average demand for individual complements decreases and becomes progressively concentrated. Furthermore, we find that prices for complements decline, whereas the costs complementors incur increase. These findings are particularly salient in the context of digital platform ecosystems, where platform sponsors can seamlessly alter their technological infrastructures and implement changes to extend and solidify their dominant positions.AMD Data Visualizatio

ADHD: Sibling interaction or dominance: An evaluation of statistical power

Sibling interaction effects are suggested by a difference in phenotypic variance between monozygotic (MZ) twins and dizygotic (DZ) twins, and a pattern of twin correlations that is inconsistent with additive genetic influences. Notably, negative sibling interaction will result in MZ correlations which are more than twice as high as DZ correlations, a pattern also seen in the presence of genetic dominance. Negative sibling interaction effects have been reported in most genetic studies on Attention Deficit Hyperactivity Disorder (ADHD) and related phenotypes, while the presence of genetic dominance is not always considered in these studies. In the present paper the statistical power to detect both negative sibling interaction effects and genetic dominance is explored. Power calculations are presented for univariate models including sources of variation due to additive genetic influences, unique environmental influences, dominant genetic influences and a negative sibling interaction (i.e., contrast effect) between phenotypes of twins. Parameter values for heritability and contrast effects are chosen in accordance with published behavior genetic studies on ADHD and associated phenotypes. Results show that when both genetic dominance and contrast effects are truly present and using a classical twin design, genetic dominance is more likely to go undetected than the contrast effect. Failure to detect the presence of genetic dominance consequently gives rise to slightly biased estimates of additive genetic effects, unique environmental effects, and the contrast effect. Contrast effects are more easily detected in the absence of genetic dominance. If the significance of the contrast effect is evaluated while also including genetic dominance, small contrast effects are likely to go undetected, resulting in a relatively large bias in estimates of the other parameters. Alternative genetic designs, such as adding pairs of unrelated siblings reared together to a classical twin design, or adding non-twin siblings to twin pairs, greatly enhances the statistical power to detect contrast effects as well as the power to distinguish between genetic dominance and contrast effects

Import of cytochrome c into mitochondria

The import of cytochrome c into mitochondria can be resolved into a number of discrete steps. Here we report on the covalent attachment of heme to apocytochrome c by the enzyme cytochrome c heme lyase in mitochondria from Neurospora crassa. A new method was developed to measure directly the linkage of heme to apocytochrome c. This method is independent of conformational changes in the protein accompanying heme attachment. Tryptic peptides of [35S]cysteine-labelled apocytochrome c, and of enzymatically formed holocytochrome c, were resolved by reverse-phase HPLC. The cysteine-containing peptide to which heme was attached eluted later than the corresponding peptide from apocytochrome c and could be quantified by counting 35S radioactivity as a measure of holocytochrome c formation. Using this procedure, the covalent attachment of heme to apocytochrome c, which is dependent on the enzyme cytochrome c heme lyase, could be measured. Activity required heme (as hemin) and could be reversibly inhibited by the analogue deuterohemin. Holocytochrome c formation was stimulated 5–10-fold by NADH > NADPH > glutathione and was independent of a potential across the inner mitochondrial membrane. NADH was not required for the binding of apocytochrome c to mitochondria and was not involved in the reduction of the cysteine thiols prior to heme attachment. Holocytochrome c formation was also dependent on a cytosolic factor that was necessary for the heme attaching step of cytochrome c import. The factor was a heat-stable, protease-insensitive, low-molecular-mass component of unknown function. Cytochrome c heme lyase appeared to be a soluble protein located in the mitochondrial intermembrane space and was distinct from the previously identified apocytochrome c binding protein having a similar location. A model is presented in which the covalent attachment of heme by cytochrome c heme lyase also plays an essential role in the import pathway of cytochrome c

Universiteit Leiden Opleiding Informatica

Abstract S.M.A.C.K. is a small and simple operating system developed at LIACS to run on the BeagleBoard. The simple design allows students to learn how operating systems work. To keep it simple only the most essential features of an operating system are implemented. One essential feature that is missing is support for storage devices. The BeagleBoard does have an SD-card slot, but there are no drivers to use it. The only way to boot is using a RAM disk that is loaded by the boot loader. This is not very convenient. It would make S.M.A.C.K. more user friendly if it was possible to access data on SD-card and directly boot from it. This thesis will describe the implementation of an SD-card driver for S.M.A.C.K. to add a support for a permanent storage device and the implementation of two methods to improve performance: DMA and a buffer cache. Several experiments were then performed to test the effectiveness of DMA and the buffer cache on the BeagleBoard. The results show that a buffer cache and DMA transfers can improve the performance in specific situations.