On arterial contractility, energetic requirements of the cardiovascular system, and the formation of arterial sclerosis

The aorta has been viewed as a passive distribution manifold for blood whose elasticity allows it to store blood during cardiac ejection (systole), and release it during relaxation (diastole). This capacitance, or compliance, lowers peak cardiac work input and maintains peripheral sanguine irrigation throughout the cardiac cycle. The compliance of the human and canine circulatory systems have been described either as constant throughout the cycle (Toy et al. 1985) or as some inverse function of pressure (Li et al. 1990, Cappelo et al. 1995). This work shows that a compliance value that is higher during systole than diastole (equivalent to a direct function of pressure) leads to a reduction in the energetic input to the cardiovascular system (CV), even when accounting for the energy required to change compliance. This conclusion is obtained numerically, based on a 3-element lumped-parameter model of the CV, then demonstrated in a physical model built for the purpose. It is then shown, based on the numerical and physical models, on analytical considerations of elastic tubes, and on the analysis of arterial volume as a function of pressure measured in vivo (Armentano et al. 1995), that the mechanical effects of a presupposed arterial contraction are consistent with those of energetically beneficial changes in compliance during the cardiac cycle. Although the amount of energy potentially saved with rhythmically contracting arteries is small (mean 0.55% for the cases studied) the importance of the phenomenon lies in its possible relation to another function of the arterial smooth muscle (ASM): synthesis of wall matrix macromolecules. It is speculated that a reduction in the rate of collagen synthesis by the ASM is implicated in the formation of arteriosclerosis. ^

An assessment of computer usage within the Bahamian public school system and recommended guidelines towards the development of a strategic national computer plan

Computers have dramatically changed the way we live, conduct business, and deliver education. They have infiltrated the Bahamian public school system to the extent that many educators now feel the need for a national plan. The development of such a plan is a challenging undertaking, especially in developing countries where physical, financial, and human resources are scarce. This study assessed the situation with regard to computers within the Bahamian public school system, and provided recommended guidelines to the Bahamian government based on the results of a survey, the body of knowledge about trends in computer usage in schools, and the country's needs. ^ This was a descriptive study for which an extensive review of literature in areas of computer hardware, software, teacher training, research, curriculum, support services and local context variables was undertaken. One objective of the study was to establish what should or could be relative to the state-of-the-art in educational computing. A survey was conducted involving 201 teachers and 51 school administrators from 60 randomly selected Bahamian public schools. A random stratified cluster sampling technique was used. ^ This study used both quantitative and qualitative research methodologies. Quantitative methods were used to summarize the data about numbers and types of computers, categories of software available, peripheral equipment, and related topics through the use of forced-choice questions in a survey instrument. Results of these were displayed in tables and charts. Qualitative methods, data synthesis and content analysis, were used to analyze the non-numeric data obtained from open-ended questions on teachers' and school administrators' questionnaires, such as those regarding teachers' perceptions and attitudes about computers and their use in classrooms. Also, interpretative methodologies were used to analyze the qualitative results of several interviews conducted with senior public school system's officials. Content analysis was used to gather data from the literature on topics pertaining to the study. ^ Based on the literature review and the data gathered for this study a number of recommendations are presented. These recommendations may be used by the government of the Commonwealth of The Bahamas to establish policies with regard to the use of computers within the public school system. ^

Characterization of L-Serine Deaminase and its Potential Role in the Pathogenicity of Pseudomonas aeruginosa

All pathogens require high energetic influxes to counterattack the host immune system and without this energy bacterial infections are easily cleared. This study is an investigation into one highly bioenergetic pathway in Pseudomonas aeruginosa involving the amino acid L-serine and the enzyme L-serine deaminase (L-SD). P. aeruginosa is an opportunistic pathogen causing infections in patients with compromised immune systems as well as patients with cystic fibrosis. Recent evidence has linked L-SD directly to the pathogenicity of several organisms including but not limited to Campylobacter jejuni, Mycobacterium bovis, Streptococcus pyogenes, and Yersinia pestis. We hypothesized that P. aeruginosa L-SD is likely to be critical for its virulence. Genome sequence analysis revealed the presence of two L-SD homo logs encoded by sdaA and sdaB. We analyzed the ability of P. aeruginosa to utilize serine and the role of SdaA and SdaB in serine deamination by comparing mutant strains of sdaA (PAOsdaA) and sdaB (PAOsdaB) with their isogenic parent P. aeruginosa P AO 1. We demonstrated that P. aeruginosa is unable to use serine as a sole carbon source. However, serine utilization is enhanced in the presence of glycine and this glycine-dependent induction of L-SD activity requires the inducer serine. The amino acid leucine was shown to inhibit L-SD activity from both SdaA and SdaB and the net contribution to L-serine deamination by SdaA and SdaB was ascertained at 34% and 66 %, respectively. These results suggest that P. aeruginosa LSD is quite different from the characterized E. coli L-SD that is glycine-independent but leucine-dependent for activation. Growth mutants able to use serine as a sole carbon source were also isolated and in addition, suicide vectors were constructed which allow for selective mutation of the sdaA and sdaB genes on any P. aeruginosa strain of interest. Future studies with a double mutant will reveal the importance of these genes for pathogenicity.

Application of a PERT-Type System and "Crashing" in a Food Service Operation

A pert-type system, a combination of the program evaluation and review technique (PERT) and the critical path method (CPM), might be used by the hospitality industry to improve planning and control of complex functions. The author discusses this management science technique and how it can assist.

Cuba's Judicial System and Transition: Lecture by Antonio G. Rodiles and Amelia Maria Rodríguez Cala

This flyer promotes the event "Cuba's Judicial System and Transition: Lecture by Antonio G. Rodiles and Amelia Maria Rodríguez Cala" cosponsored by the FlU College of Law and the Vaclav Hável Initiative for Human Rights and Diplomacy.

Event mining for system and service management

Modern IT infrastructures are constructed by large scale computing systems and administered by IT service providers. Manually maintaining such large computing systems is costly and inefficient. Service providers often seek automatic or semi-automatic methodologies of detecting and resolving system issues to improve their service quality and efficiency. This dissertation investigates several data-driven approaches for assisting service providers in achieving this goal. The detailed problems studied by these approaches can be categorized into the three aspects in the service workflow: 1) preprocessing raw textual system logs to structural events; 2) refining monitoring configurations for eliminating false positives and false negatives; 3) improving the efficiency of system diagnosis on detected alerts. Solving these problems usually requires a huge amount of domain knowledge about the particular computing systems. The approaches investigated by this dissertation are developed based on event mining algorithms, which are able to automatically derive part of that knowledge from the historical system logs, events and tickets. ^ In particular, two textual clustering algorithms are developed for converting raw textual logs into system events. For refining the monitoring configuration, a rule based alert prediction algorithm is proposed for eliminating false alerts (false positives) without losing any real alert and a textual classification method is applied to identify the missing alerts (false negatives) from manual incident tickets. For system diagnosis, this dissertation presents an efficient algorithm for discovering the temporal dependencies between system events with corresponding time lags, which can help the administrators to determine the redundancies of deployed monitoring situations and dependencies of system components. To improve the efficiency of incident ticket resolving, several KNN-based algorithms that recommend relevant historical tickets with resolutions for incoming tickets are investigated. Finally, this dissertation offers a novel algorithm for searching similar textual event segments over large system logs that assists administrators to locate similar system behaviors in the logs. Extensive empirical evaluation on system logs, events and tickets from real IT infrastructures demonstrates the effectiveness and efficiency of the proposed approaches.^

The Prison System and the Media: How “Orange Is The New Black” Engages with the Prison as a Normalizing Agent

The purpose of this project is to ascertain the ways in which Orange is the New Black uses its platform to either complicate or reify narratives about the prison system, prisoners and their relationship to the state. This research uses the works of Giorgio Agamben, Colin Dayan, Michelle Alexander and Lisa Guenther to situate the ways the state uses the prison and social narratives about the prison to extend its control on certain populations beyond prison walls through police presence, parole, the war on drugs and prison fees. From that basis, this work argues that while Orange does challenge some narratives about race and sexuality, because of its reliance on “bad choices” as a humanizing trope and its reliance on certain racialized stereotypes for entertainment, the show ultimately does more to reify existing narratives that support state interests.