Trading volume and firm‐specific announcements: Implications for the market model

The market model is commonly used in finance to study events and to evaluate security performance. With daily data, it is not uncommon to find low R‐squares, in the range 0–10%. Prior studies have attempted to improve the fit of the model by excluding observations associated with high trading volume. In this study, we compare the results of the high‐volume‐exclusion approach with the more direct firm‐specific announcement exclusion approach. The announcement approach excludes observations associated with Wall Street Journal Index news items regarding the firm. By excluding the [−1,0] fays relative to such news in a sample of 68 firms, we find that R‐squares increase significantly by about 5%. By excluding the days relative to earnings announcements only, R‐squares increase by about 4%. These results are then compared to the high‐volume‐exclusion approach. It is found that this approach is more efficient as an 8% increase in R‐squares is produced.The results of this study provide valuable evidence to empiricists by comparing the two approaches to improving the fit of the market model. The high‐volume ‐exclusion approach provides higher R‐squares. However, the relative efficiency of the two approaches should be balanced against the arguments for the methodologically correct approach. The advantage of using the firm‐specific announcement exclusion approach is that there is more confidence of excluding only firm‐specific movements from the estimation of the market model. It also allows a researcher to quickly and unambiguously identify the announcements and delete the corresponding observations. Furthermore, we find that about 50% of the improved fit, relative to the volume approach, can be accomplished by excluding earnings announcements. The methodological disadvantage of using the high‐volume‐exclusion approach is that it is affected not only by firm‐specific announcements but also by other factors, such as the heterogeneity of investor expectations. These factors may influence the choice of using firm‐specific announcements rather than the high‐volume approach despite the lower increment in R‐squares.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142312/1/rfe183.pd

A Baldrige Portfolio: Does Quality Outperform The Market?

This paper investigates the claim, by the Department of Commerce, that a portfolio of Baldrige National Quality Award winners outperforms the market.  They find that there is a 92 percent return for Baldrige winners as compared to a 33 percent return on the S&P 500 index.  Their results are published and used to promote “quality” in Department of Commerce press releases.  Our findings do not support their claim that investors can handsomely outperform the market by investing in a Baldrige portfolio.  We find that their study is sensitive to risk measurement and that extending the time horizon alone eliminates any advantage.  Our examination of long-run stock price performance of Baldrige firms also does not support their claim of outperforming the market

Capital Budgeting and State Approval of Power Plants

John A. Helmuth is an Associate Professor of Finance in the Department of Accounting and Finance, College of Business Administration at Rochester Institute of Technology. Donald Kent is an Assistant Professor of Accounting at Robert Wesleyan College, Rochester, New York. Jeffrey P. Lessard is an Assistant Professor of Finance in the Department of Accounting and Finance, College of Business Administration at Rochester lnstitute of Technology

Peripheral blood lymphocyte proviral DNA predicts neurocognitive impairment in clade C HIV

CITATION: Ruhanya, V. et al. 2020. Peripheral blood lymphocyte proviral DNA predicts neurocognitive impairment in clade C HIV. Journal of NeuroVirology, 26:920–928, doi:10.1007/s13365-020-00882-9.The original publication is available at https://link.springer.comIt is not known if proviral DNA in the periphery corresponds to cognitive status in clade C as it does in clade B and recombinant forms. A cross-sectional study was conducted on participants investigated for HIV-associated neurocognitive impairment in South Africa. HIV-1 proviral DNA was quantified using a PCR assay targeting a highly conserved HIV-1 LTR-gag region. Fifty-four (36.7%) participants were cognitively impaired and 93 (63.3%) were not impaired. Forty-three (79.6%) of the cognitively impaired participants were female and 11 (20.4%) were male. There was no significant age difference between cognitively impaired and unimpaired participants (p = 0.42). HIV-1 DNA in cognitively impaired PLWH was significantly higher than in cognitively normal individuals (p = .016). Considering impaired participants, lymphocyte HIV-1 DNA was significantly higher in males than females (p = 0.02). There was a modest positive correlation between lymphocyte HIV-1 DNA and global deficit scores (GDS) r = 0.176; p = 0.03). The two measures of viral load, lymphocyte HIV-1 DNA copies/million and plasma RNA copies/ml, were positively correlated (r = 0.39; p < .001). After adjusting for other covariates, age, sex, treatment status, and the interactions between impairment and treatment, the multivariate regression showed association between proviral load and neurocognitive impairment; omega effect size was 0.04, p value = 0.010. The burden of HIV-1 peripheral blood lymphocyte proviral DNA corresponds to neurocognitive impairment among individuals infected with clade C disease. Therefore, therapeutic strategies to reduce the HIV-1 proviral DNA reservoir in lymphocytes may improve neurocognitive outcomes in PLWH.Poliomyelitis Research Foundation (PRF)National Research Foundation (NRF)South African Medical Research Council (SAMRC)Publisher's versio

Spiders from Mexico.

19 p. : ill. ; 24 cm.Includes bibliographical references

Warming and Resource Availability Shift Food Web Structure and Metabolism

Experimental warming of a marine food web suggests that ocean warming can lead to greater consumer abundance but reduced overall biomass, providing a potentially species-independent response to environmental warming

Thermal Stress and Coral Cover as Drivers of Coral Disease Outbreaks

Very little is known about how environmental changes such as increasing temperature affect disease dynamics in the ocean, especially at large spatial scales. We asked whether the frequency of warm temperature anomalies is positively related to the frequency of coral disease across 1,500 km of Australia's Great Barrier Reef. We used a new high-resolution satellite dataset of ocean temperature and 6 y of coral disease and coral cover data from annual surveys of 48 reefs to answer this question. We found a highly significant relationship between the frequencies of warm temperature anomalies and of white syndrome, an emergent disease, or potentially, a group of diseases, of Pacific reef-building corals. The effect of temperature was highly dependent on coral cover because white syndrome outbreaks followed warm years, but only on high (>50%) cover reefs, suggesting an important role of host density as a threshold for outbreaks. Our results indicate that the frequency of temperature anomalies, which is predicted to increase in most tropical oceans, can increase the susceptibility of corals to disease, leading to outbreaks where corals are abundant

The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (v(r)*) (v(r)* 5 0 indicating excellent agreement and v(r)* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1-4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1-4.4) for panel members and 4.5 (95% CI 4.3-4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1-4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9-4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (v(r)*) for both cohorts was 0.026 (95% CI 0.019-0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.Peer reviewe

Swimming with Predators and Pesticides: How Environmental Stressors Affect the Thermal Physiology of Tadpoles

To forecast biological responses to changing environments, we need to understand how a species’s physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4uC higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5uC, while exposure to the herbicide marginally lowered Topt by 0.4uC. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5uC higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.Peer reviewe