Keeping Public Colleges Affordable: A Study of Persistence in Indiana\u27s Public Colleges and Universities

It is important for states to assess periodically the effects of student aid on persistence in the public systems of higher education. Recently, a workable persistence model has emerged that can be used for this purpose. This paper uses the model to examine the influence of student aid on persistence by full-time resident undergraduates enrolled in Indiana\u27s public system of higher education during the 1997-98 academic year. The analysis reveals that student financial aid was adequate, largely due to a substantial state investment in need-based grants

Persistence by Undergraduates in an Urban Public University: Understanding the Effects of Financial Aid

The decline in federal grants over the past two decades could be problematic for urban higher education because of the concentration of poverty in urban settings. This case study examines the effects of student aid on within-year persistence at an urban public university in the 1990s. The analyses indicate that aid packages remained adequate at this urban university. It appears that state and institutional grants play an increasingly important role in maintaining affordability in this new context of higher tuition and higher loans

Optimizing the Optoelectronic Properties of Conjugated Polymers Through Metal-Ligand Coordination

From the phones at our fingertips to the solar panels on our roofs, humans are becoming increasingly dependent on electronics for information, entertainment, and to power their daily lives. Further advancements are paving the way for a new age of high-performance, flexible devices. Organic electronics made from conjugated semiconducting polymers are showing great potential as a softer and more processable material than brittle silicon used in today’s devices, while exhibiting comparable charge transport to silicon. However, one key challenge with these organic polymers is the difficulty to control their optical properties and charge transport in devices. Electronics must interact with and alter their lighting while efficiently conducting electricity. Therefore, the desired material must be tuneable to precisely control these important properties. In this research, a novel organic diketopyrrolopyrrole-based conjugated polymer is presented as a leading candidate for optoelectronics. This polymer uses noncovalent metal-ligand interactions, enabled by using specific terpyridine ligands, to fine-tune its ability to emit light and transport electrons. Various transition metal ions, including Fe2+, Co2+, Zn2+, and Mn2+, were introduced into the polymer to determine which species would coordinate most efficiently with the ligand, altering its optical nature. Results from fluorescence and absorption spectroscopies showed that the manganese ion coordinated the weakest to the ligand, while iron and cobalt ions bound the most efficiently and optimally altered emission intensity. Thus, iron and cobalt were identified as great candidates for metal-ligand coordination within the polymer for optimal optoelectronic capabilities. These findings contribute to the continued pursuit of creating efficient organic optoelectronics through the promising technique of metal-ligand interactions. Keywords: organic electronics, conjugated polymer, optoelectronics, metal-ligand interaction

Energy Relaxation in Nonlinear One-Dimensional Lattices

We study energy relaxation in thermalized one-dimensional nonlinear arrays of the Fermi-Pasta-Ulam type. The ends of the thermalized systems are placed in contact with a zero-temperature reservoir via damping forces. Harmonic arrays relax by sequential phonon decay into the cold reservoir, the lower frequency modes relaxing first. The relaxation pathway for purely anharmonic arrays involves the degradation of higher-energy nonlinear modes into lower energy ones. The lowest energy modes are absorbed by the cold reservoir, but a small amount of energy is persistently left behind in the array in the form of almost stationary low-frequency localized modes. Arrays with interactions that contain both a harmonic and an anharmonic contribution exhibit behavior that involves the interplay of phonon modes and breather modes. At long times relaxation is extremely slow due to the spontaneous appearance and persistence of energetic high-frequency stationary breathers. Breather behavior is further ascertained by explicitly injecting a localized excitation into the thermalized array and observing the relaxation behavior

Increased hyperpolarized [1-13 C] lactate production in a model of joint inflammation is not accompanied by tissue acidosis as assessed using hyperpolarized 13 C-labelled bicarbonate.

Arthritic conditions are a major source of chronic pain. Furthering our understanding of disease mechanisms creates the opportunity to develop more targeted therapeutics. In rheumatoid arthritis (RA), measurements of pH in human synovial fluid suggest that acidosis occurs, but that this is highly variable between individuals. Here we sought to determine if tissue acidosis occurs in a widely used rodent arthritis model: complete Freund's adjuvant (CFA)-induced inflammation. CFA robustly evoked paw and ankle swelling, concomitant with worsening clinical scores over time. We used magnetic resonance spectroscopic imaging of hyperpolarized [1-13 C]pyruvate metabolism to demonstrate that CFA induces an increase in the lactate-to-pyruvate ratio. This increase is indicative of enhanced glycolysis and an increased lactate concentration, as has been observed in the synovial fluid from RA patients, and which was correlated with acidosis. We also measured the 13 CO2 /H13 CO3- ratio, in animals injected with hyperpolarized H13 CO3- , to estimate extracellular tissue pH and showed that despite the apparent increase in glycolytic activity in CFA-induced inflammation there was no accompanying decrease in extracellular pH. The pH was 7.23 ± 0.06 in control paws and 7.32 ± 0.09 in inflamed paws. These results could explain why mice lacking acid-sensing ion channel subunits 1, 2 and 3 do not display any changes in mechanical or thermal hyperalgesia in CFA-induced inflammation

An evaluation of whole blood testing for Helicobacter pylori infection in the Chinese population

Background: Near patient tests for Helicobacter pylori were developed to assist in the management of dyspepsia patients in general practice. Most studies were performed in western populations. Aim: To evaluate the rapid whole blood test (Flexpack HP) for H. pylori in the Chinese population. Methods: Consecutive dyspeptic patients referred for upper endoscopy were recruited. During upper endoscopy, biopsies were taken from the antrum and corpus for rapid urease test (CLO test) and histological examination. After endoscopy, the whole blood test (FlexPack HP) was performed according to the manufacturer's instruction. Patients then received a 13C-urea breath test. Results of the whole blood test were compared with the gold standard (CLO test, histology and 13C-urea breath test). Results: A total of 294 consecutive patients gave a valid Flexpack HP result for interpretation. The mean age of patients was 47.7 (range 15-85) years. Analysis showed a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 58%, 92%, 91%, 63% and 73% respectively. Conclusion: The FlexPack HP whole blood test showed good specificity but lacked sensitivity. It is not sensitive enough to be used in a general practice setting for the test-and-treat approach in the Chinese population.postprin

Antralization at the edge of proximal gastric ulcers: Does Helicobacter pylori infection play a role?

Aim: To determine the prevalence of antralization at the edge of proximal gastric ulcers, and the effect of H. pylori eradication on the mucosal appearances. Methods: Biopsies were taken from the antrum, body and the ulcer edge of patients with benign proximal gastric ulcers before and one year after treatment. Gastric mucosa was classified as antral, transitional or body type. H. pylori positive patients received either triple therapy, or omeprazole. Results: Patients with index ulcers in the incisura, body or fundus (n=116) were analyzed. Antral-type mucosa was more prevalent at the ulcer edge in H. pylori-positive patients than H. pylori-negative patients (93 % vs 60 %, OR=8.95, 95 %CI: 2.47-32.4, P=0.001). At one year, there was a significant reduction in the prevalence of antralization (from 93 % to 61 %, P=0.004) at the ulcer edge in patients with H. pylori being eradicated. However, there was no difference in the prevalence of antralization at the ulcer edge in those with persistent infection. Conclusion: H. pylori infection is associated with antralization at the edge of proximal gastric ulcers, which may be reversible in some patients after eradication of the infection.published_or_final_versio