The Information Content of Standard & Poor\u27s Common Stock Ranking Changes

This study examines the information content of Standard & Poor\u27s common stock ranking changes. These rankings are derived from a system which begins with a computer-generated score for per-share growth, stability, and cyclicality of earnings and dividends for the most recent ten years of available data. Standard & Poor\u27s then makes adjustments to the scores based on firm size, sales volume, relative current standing,\u271 and special considerations. The eight rankings are as follows: A+ (Highest), A (High), A- (Above Average), B+ (Average), B (Below Average), B- (Lower), C (Lowest), and D (In Reorganization). Although the rankings are not purported to be buy or sell recommendations, they do incorporate information provided by standard & Poor\u27s on which investors may base investment decisions. Haugen [1979], and Muller, Fielitz, and Greene [1983, 1984] find that the rankings are closely related to risk, as measured by beta and the standard deviation of returns, while the rankings are not a reliable measure of return. Standard & Poor\u27s makes common stock ranking changes daily. A ranking change can be either an upgrade, a downgrade, the initiation of a ranking, or the withdrawal of a ranking. The ranking changes are initially revealed by Standard & Poor\u27s via internal memoranda. The memoranda are released daily to a time-share service which provides the information to its customers. The ranking changes are subsequently published at the end of the month in the Stock Guide. Daily memoranda for the 1,879 ranking changes from June 1985 to May 1987 were obtained from Standard & Poor\u27s. Using the market model, stock prices are found to be fully adjusted by day 0, the memorandum date, for both the All Upgrades and the All Downgrades portfolios. However, the adjustment process differs by type of ranking change. The results from a Wall Street Journal Index search indicate that Standard & Poor\u27s changes rankings following earnings announcements. While no relation is found between rankings and return, a close relation is found between rankings and risk, both before and after a ranking change. Also, a statistically significant fall in the mean beta for the All Upgrades portfolio is found following the memorandum date. Thus, firms upgraded by Standard & Poor\u27s are found to have less risk in the post-event period than in the pre-event period

A study of the heat transfer characteristics in a fin type evaporator

M.S.R. S. King and A. D. Hollan

The Fundamental Interactions Between Hydrogen and group III-VI and IV-VI van der Waals Crystals

Eighteen years since the exfoliation of graphene was first demonstrated, van der Waals (vdW) materials have attracted incredible fundamental and applied research interest. The sustained level of interest can be attributed to the unique properties and the diversity of vdW crystals, which can be readily exfoliated via the simple method first used for graphene. Over the same period, a renewed wave of hydrogen research has emerged with the aim of reducing greenhouse gas emissions. As such, the two fields have often intersected, with the properties of vdW materials often well suited to applications in hydrogen storage, sensing, generation and purification. This PhD considers the fundamental interactions of vdW materials with hydrogen. Specifically, the focus of this work is on the interactions with the vdW semiconductors SnS2, SnS, γ-InSe and ϵ-GaSe. It was found that SnS2 can be converted to SnS upon hydrogen exposure, producing a heterostructure with surprising uniformity and a step-like interface. Exposure of γ-InSe to H-ions modifies its optical and vibrational properties, whilst theoretical studies reveal an exciting modification to the phonon modes upon H2 incorporation. Finally, water exposed ϵ-GaSe is partially oxidised, modifying its electronic band structure, relevant to solar water splitting applications. These results are of fundamental interest and relevant to both hydrogen and semiconductor technologies, ranging from engineered vdW heterostructures and optoelectronics, to hydrogen storage and generation

The Fundamental Interactions Between Hydrogen and group III-VI and IV-VI van der Waals Crystals

Eighteen years since the exfoliation of graphene was first demonstrated, van der Waals (vdW) materials have attracted incredible fundamental and applied research interest. The sustained level of interest can be attributed to the unique properties and the diversity of vdW crystals, which can be readily exfoliated via the simple method first used for graphene. Over the same period, a renewed wave of hydrogen research has emerged with the aim of reducing greenhouse gas emissions. As such, the two fields have often intersected, with the properties of vdW materials often well suited to applications in hydrogen storage, sensing, generation and purification. This PhD considers the fundamental interactions of vdW materials with hydrogen. Specifically, the focus of this work is on the interactions with the vdW semiconductors SnS2, SnS, γ-InSe and ϵ-GaSe. It was found that SnS2 can be converted to SnS upon hydrogen exposure, producing a heterostructure with surprising uniformity and a step-like interface. Exposure of γ-InSe to H-ions modifies its optical and vibrational properties, whilst theoretical studies reveal an exciting modification to the phonon modes upon H2 incorporation. Finally, water exposed ϵ-GaSe is partially oxidised, modifying its electronic band structure, relevant to solar water splitting applications. These results are of fundamental interest and relevant to both hydrogen and semiconductor technologies, ranging from engineered vdW heterostructures and optoelectronics, to hydrogen storage and generation

Pedestrian Infrastructure Improvements: Effects on Transit Use and Perceptions of the Pedestrian Environment in Portland\u27s Roseway Neighborhood

Over the past two years the Pedestrian Transportation (PTP) of the City of Portland has been engaged in a project to encourage walking and transit use through targeted infrastructure improvements. These improvements are intended to enhance pedestrian access to transit service by aiding street crossing and providing more amenities at bus stops. Other improvements include landscaping, sidewalks, curb extensions and ramps, and improved street lighting. One of the basic assumptions of this project is that the pedestrian environment is related to transportation choices. This report explores that assumption

Host plant defense produces species-specific alterations to flight muscle protein structure and flight-related fitness traits of two armyworms

Insects manifest phenotypic plasticity in their development and behavior in response to plant defenses, via molecular mechanisms that produce tissue-specific changes. Phenotypic changes might vary between species that differ in their preferred hosts and these effects could extend beyond larval stages. To test this,we manipulated the diet of southern armyworm(SAW; Spodoptera eridania) and fall armyworm (FAW; Spodoptera frugiperda) using a tomato mutant for jasmonic acid plant defense pathway (def1), and wild-type plants, and then quantified gene expression of Troponin t (Tnt) and flightmusclemetabolismof the adult insects. Differences in Tnt spliceform ratios in insect flight muscles correlate with changes to flight muscle metabolism and flight muscle output. We found that SAW adults reared on induced def1 plants had a higher relative abundance (RA) of the A isoform of Troponin t (Tnt A) in their flight muscles; in contrast, FAWadults reared on induced def1 plants had a lower RA of Tnt A in their flight muscles compared with adults reared on def1 and controls. Although massadjusted flightmetabolic rate showed no independent host plant effects in either species, higher flight metabolic rates in SAW correlated with increased RA of Tnt A. Flight muscle metabolism also showed an interaction of host plants with Tnt A in both species, suggesting that host plants might be influencing flight muscle metabolic output by altering Tnt. This study illustrates how insects respond to variation in host plant chemical defense by phenotypic modifications to their flight muscle proteins, with possible implications for dispersal

Green tea polyphenols and Tai Chi for bone health: Designing a placebo-controlled randomized trial

BACKGROUND: Osteoporosis is a major health problem in postmenopausal women. Evidence suggests the importance of oxidative stress in bone metabolism and bone loss. Tea consumption may be beneficial to osteoporosis due to its antioxidant capability. However, lack of objective data characterizing tea consumption has hindered the precise evaluation of the association between tea ingestion and bone mineral density in previous questionnaire-based epidemiological studies. On the other hand, although published studies suggest that Tai Chi (TC) exercise can benefit bone health and may reduce oxidative stress, all studies were conducted using a relatively healthy older population, instead of a high-risk one such as osteopenic postmenopausal women. Therefore, this study was designed to test an intervention including green tea polyphenol (GTP) and TC exercise for feasibility, and to quantitatively assess their individual and interactive effects on postmenopausal women with osteopenia. METHODS/DESIGN: One hundred and forty postmenopausal women with osteopenia (defined as bone mineral density T-score at the spine and/or hip between 1 to 2.5 SD below the reference database) were randomly assigned to 4 treatment arms: (1) placebo group receiving 500 mg medicinal starch daily, (2) GTP group receiving 500 mg of GTP per day, (3) placebo+TC group receiving both placebo treatment and TC training (60-minute group exercise, 3 times per week), and (4) GTP+TC group receiving both GTP and TC training for 24 weeks. The outcome measures were bone formation biomarker (serum bone alkaline phosphatase), bone resorption biomarker (serum tartrate resistant acid phosphatase), and oxidative DNA damage biomarker (urinary 8-hydroxy-2'-deoxyguanosine). All outcome measures were determined at baseline, 4, 12, and 24 weeks. Urinary and serum GTP concentrations were also determined at baseline, 4, 12, and 24 weeks for bioavailability. Liver function was monitored monthly for safety. A model of repeated measurements with random effect error terms was applied. Traditional procedures such as ANCOVA, chi-squared analysis, and regression were used for comparisons. DISCUSSION: We present the rationale, design, and methodology of a placebo-controlled randomized trial to investigate a new complementary and alternative medicine strategy featuring a dietary supplement and a mind-body exercise for alleviating bone loss in osteopenic postmenopausal women. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT0062539