Investment Patterns and Financial Leverage

This study Investigates the influence of the type of investment opportunities facing a firm on its choice of capital structure. It is shown that the more discretionary investment opportunities a firm faces,the lower its financial leverage. Inclusion of other possible determinants of capital structure, such as availability of internal funds, tax effects and risk, while significant, do not affect the importance of discretionary investment. The evidence supports (1) the existence of a moral bazzard problem which inversely relates risky debt and discretionary investment choice, and (2) a desire by most firms to use sources of internal funds prior to entering the capital market.

Brain Volumetrics, Regional Cortical Thickness and Radiographic Findings in Adults with Cyanotic Congenital Heart Disease

AbstractBackgroundChronic cyanosis in adults with congenital heart disease (CHD) may cause structural brain changes that could contribute to impaired neurological functioning. The extent of these changes has not been adequately characterized.HypothesisWe hypothesized that adults with cyanotic CHD would have widespread changes including abnormal brain volumetric measures, decreased cortical thickness and an increased burden of small and large vessel ischemic changes.MethodsTen adults with chronic cyanosis from CHD (40±4years) and mean oxygen saturations of 82±2% were investigated using quantitative MRI. Hematological and biochemical parameters were also assessed. All subjects were free from major physical or intellectual impairment. Brain volumetric results were compared with randomly selected age- and sex-matched controls from our database of normal subjects.ResultsFive of 10 cyanotic subjects had cortical lacunar infarcts. The white matter (WM) hyperintensity burden was also abnormally high (Scheltens Scale was 8±2). Quantitative MRI revealed evidence of extensive generalized WM and gray matter (GM) volumetric loss; global GM volume was reduced in cyanosed subjects (630±16 vs. 696±14mL in controls, p=0.01) as was global WM volume (471±10 vs. 564±18mL, p=0.003). Ventricular cerebrospinal fluid volume was increased (35±10 vs. 26±5mL, p=0.002). There were widespread regions of local cortical thickness reduction observed across the brain. These changes included bilateral thickness reductions in the frontal lobe including the dorsolateral prefrontal cortex and precentral gyrus, the posterior parietal lobe and the middle temporal gyrus. Sub-cortical volume changes were observed in the caudate, putamen and in the thalamus (p≤0.005 for all regions). Cortical GM volume negatively correlated with brain natriuretic peptide (R=−0.89, p=0.009), high sensitivity C-reactive protein (R=−0.964, p<0.0001) and asymmetric dimethylarginine (R=−0.75, p=0.026) but not with oxygen saturations, packed cell volume or viscosity.ConclusionsWe present the first comprehensive analysis of brain structure in adults with chronic neurocyanosis due to congenital heart disease. We demonstrate clear evidence for marked macro- and microvascular injury. Cyanotic patients show global evidence for reduced brain volume as well as specific foci of cortical thickness reduction. The GM volume loss correlated with hsCRP, BNP and ADMA suggesting that inflammation, neurohormonal activation and endothelial dysfunction may have important roles in its pathogenesis

Strategic Activity and Financial Performance of U.S. Rural Hospitals: A National Study, 1983 to 1988

This study examines the effect of 13 strategic management activities on the financial performance of a national sample of 797 U.S. rural hospitals during the period of 1983-1988. Controlled for environment-market, geographic-region, and hospital-related variables, the results show almost no measurable effect of strategic adoption on rural hospital profitability and liquidity. Where statistically significant relationships existed, they were more often negative than positive. These findings were not expected; it was hypothesized that positive effects across a broad range of strategies would emerge, other things being equal. Discussed are possible explanations for these findings as well as their implication for a rural health policy relying on individual rural hospital strategic adaptation to environmental change.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72301/1/j.1748-0361.1994.tb00225.x.pd

Lombardi Drawings of Graphs

We introduce the notion of Lombardi graph drawings, named after the American abstract artist Mark Lombardi. In these drawings, edges are represented as circular arcs rather than as line segments or polylines, and the vertices have perfect angular resolution: the edges are equally spaced around each vertex. We describe algorithms for finding Lombardi drawings of regular graphs, graphs of bounded degeneracy, and certain families of planar graphs.Comment: Expanded version of paper appearing in the 18th International Symposium on Graph Drawing (GD 2010). 13 pages, 7 figure

Interventions Delivered in Clinical Settings are Effective in Reducing Risk of HIV Transmission Among People Living with HIV: Results from the Health Resources and Services Administration (HRSA)’s Special Projects of National Significance Initiative

To support expanded prevention services for people living with HIV, the US Health Resources and Services Administration (HRSA) sponsored a 5-year initiative to test whether interventions delivered in clinical settings were effective in reducing HIV transmission risk among HIV-infected patients. Across 13 demonstration sites, patients were randomized to one of four conditions. All interventions were associated with reduced unprotected vaginal and/or anal intercourse with persons of HIV-uninfected or unknown status among the 3,556 participating patients. Compared to the standard of care, patients assigned to receive interventions from medical care providers reported a significant decrease in risk after 12 months of participation. Patients receiving prevention services from health educators, social workers or paraprofessional HIV-infected peers reported significant reduction in risk at 6 months, but not at 12 months. While clinics have a choice of effective models for implementing prevention programs for their HIV-infected patients, medical provider-delivered methods are comparatively robust

Planar and Poly-Arc Lombardi Drawings

In Lombardi drawings of graphs, edges are represented as circular arcs, and the edges incident on vertices have perfect angular resolution. However, not every graph has a Lombardi drawing, and not every planar graph has a planar Lombardi drawing. We introduce k-Lombardi drawings, in which each edge may be drawn with k circular arcs, noting that every graph has a smooth 2-Lombardi drawing. We show that every planar graph has a smooth planar 3-Lombardi drawing and further investigate topics connecting planarity and Lombardi drawings.Comment: Expanded version of paper appearing in the 19th International Symposium on Graph Drawing (GD 2011). 16 pages, 8 figure

Min-Max Coverage in Multi-interface Networks

International audienceWe consider devices equipped with multiple wired or wireless interfaces. By switching among interfaces or by combining the available interfaces, each device might establish several connections. A connection is established when the devices at its endpoints share at least one active interface. Each interface is assumed to require an activation cost. In this paper, we consider the problem of establishing the connections defined by a network G = (V,E) while keeping as low as possible the maximum cost set of active interfaces at the single nodes. Nodes V represent the devices, edges E represent the connections that must be established. We study the problem of minimizing the maximum cost set of active interfaces among the nodes of the network in order to cover all the edges. We prove that the problem is NP-hard for any fixed Δ ≥ 5 and k ≥ 16, with Δ being the maximum degree, and k being the number of different interfaces among the network. We also show that the problem cannot be approximated within Ω(ln Δ). We then provide a general approximation algorithm which guarantees a factor of O((1 + b)ln (Δ)), with b being a parameter depending on the topology of the input graph. Interestingly, b can be bounded by a constant for many graph classes. Other approximation and exact algorithms for special cases are presented