Management Strategies in Cardiac Surgery for Postoperative Atrial Fibrillation: Contemporary Prophylaxis and Futuristic Anticoagulant Possibilities

With more than a third of patients expected to endure the arrhythmia at any given time point, atrial fibrillation after cardiac surgery becomes a vexing problem in the postoperative care of cardiac surgery patients. The impact on patient care covers a spectrum from the more common clinically insignificant sequelae to debilitating embolic events. Despite this, postoperative atrial fibrillation generally masquerades as being insignificant, or at most as an anticipated inherent risk, merely extending one's hospital stay by a few days. As an independent risk factor for stroke, early and late mortality, and being a multibillion dollar strain on the healthcare system annually, postoperative atrial fibrillation is far more flagrant than a mere inherent risk. It is a serious medical quandary, which is not recognized as such. Though complete prevention is unrealistic, a step-wise treatment strategy that incorporates multiple preventative modalities can significantly reduce the impact of postoperative atrial fibrillation on patient care. The aims of this review are to present a brief overview of the arrhythmia's etiology, risk factors, and preventative strategies to reduce associated morbidities. Newer anticoagulants and the potential role of these drugs on future treatment paradigms are also discussed

An Experimental Study of Effects of Overlaying Tissues on HIFU Lesion

Understanding the effect of overlaying tissues on HIFU lesion is crucial for estimating HIFU dose distribution at a target tissue. We have run a series of experiments to systematically observe the effects of the overlaying tissues on the HIFU beam and ultimately the lesion created in the target tissue. First, we mapped out the HIFU transducer beam (in low power) under water without and with different overlaying tissue layers. Then, we performed a series of experiments in high power to create lesions in target tissues (e.g., liver) without and with overlaying tissues (e.g. muscle). The lesions are characterized by slicing the tissues and reconstructing the 3D lesion from calibrated pictures of the target tissue slices. The low power beam measurements show significant effects in terms of severe beam wave‐field amplitude distortion due to phase aberration introduced by velocity inhomogeneity in the overlaying tissues. These results compare well qualitatively with the computational models. The results from the high power HIFU lesions in a similar setup using various tissues, including liver and muscle, provide understanding of the significance of phase aberration in overlaying tissues and could prove useful towards high precision HIFU therapy

Limited rigor in studies of raptor mortality and mitigation at wind power facilities

Wind power is an expanding source of renewable energy. However, there are ecological challenges related to wind energy generation, including collisions of wildlife with turbines. Lack of rigor, and variation in study design, together limit efforts to understand the broad-scale effects of wind power infrastructure on wildlife populations. It is not clear, however, whether these types of limitations apply to groups of birds such as raptors that are particularly vulnerable to negative effects of wind energy. We reviewed 672 peer-reviewed publications, unpublished reports, and citations from 321 wind facilities in 12 countries to evaluate methods used to monitor and mitigate for wind facility impacts on raptors. Most reports that included raptor monitoring (86 %, n = 461) only conducted post-construction monitoring for raptor fatalities, while few (12 %; n = 65) estimated preconstruction raptor use. Only 27 % of facilities (n = 62) provided estimates of fatalities or raptor use across multiple construction phases, and the percentage of facilities with data available from multiple construction periods has not changed over time. A formal experimental study design was incorporated into surveys at only 29 % of facilities. Finally, mitigation practices to reduce impacts on raptors were only reported at 23 % of facilities. Our results suggest that rigorous data collection on wind energy impacts to raptors is rare, and that mitigation of detrimental effects is seldom reported. Expanding the use of rigorous research approaches and increasing data availability would improve understanding of the regional and global effects of wind energy on raptor populations

The Herschel Stripe 82 Survey (HerS): maps and early catalog

We present the first set of maps and band-merged catalog from the Herschel Stripe 82 Survey (HerS). Observations at 250, 350, and 500μm were taken with the Spectral and Photometric Imaging Receiver instrument aboard the Herschel Space Observatory. HerS covers 79deg 2 along the SDSS Stripe 82 to an average depth of 13.0, 12.9, and 14.8mJybeam −1 (including confusion) at 250, 350, and 500μm, respectively. HerS was designed to measure correlations with external tracers of the dark matter density field—either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing)—in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty star-forming galaxies and active galactic nuclei. By locating HerS in Stripe 82, we maximize the overlap with available and upcoming cosmological surveys. The band-merged catalog contains 3.3 × 10 4 sources detected at a significance of ?3σ (including confusion noise). The maps and catalog are available at http://www.astro.caltech.edu/hers/

Late outcomes comparison of nonelderly patients with stented bioprosthetic and mechanical valves in the aortic position: A propensity-matched analysis

ObjectiveOur study compares late mortality and valve-related morbidities between nonelderly patients (aged <65 years) undergoing stented bioprosthetic or mechanical valve replacement in the aortic position.MethodsWe identified 1701 consecutive patients aged <65 years who underwent aortic valve replacement between 1992 and 2011. A stented bioprosthetic valve was used in 769 patients (45%) and a mechanical valve was used in 932 patients (55%). A stepwise logistic regression propensity score identified a subset of 361 evenly matched patient-pairs. Late outcomes of death, reoperation, major bleeding, and stroke were assessed.ResultsFollow-up was 99% complete. The mean age in the matched cohort was 53.9 years (bioprosthetic valve) and 53.2 years (mechanical valve) (P = .30). Fifteen additional measurable variables were statistically similar for the matched cohort. Thirty-day mortality was 1.9% (bioprosthetic valve) and 1.4% (mechanical valve) (P = .77). Survival at 5, 10, 15, and 18 years was 89%, 78%, 65%, and 60% for patients with bioprosthetic valves versus 88%, 79%, 75%, and 51% for patients with mechanical valves (P = .75). At 18 years, freedom from reoperation was 95% for patients with mechanical valves and 55% for patients with bioprosthetic valves (P = .002), whereas freedom from a major bleeding event favored patients with bioprosthetic valves (98%) versus mechanical valves (78%; P = .002). There was no difference in stroke between the 2 matched groups.ConclusionsIn patients aged <65 years, despite an increase in the rate of reoperation with stented bioprosthetic valves and an increase in major bleeding events with mechanical valves, there is no significant difference in mortality at late follow-up

Ernst Freund as Precursor of the Rational Study of Corporate Law

Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe

The Red Sea, Coastal Landscapes, and Hominin Dispersals

This chapter provides a critical assessment of environment, landscape and resources in the Red Sea region over the past five million years in relation to archaeological evidence of hominin settlement, and of current hypotheses about the role of the region as a pathway or obstacle to population dispersals between Africa and Asia and the possible significance of coastal colonization. The discussion assesses the impact of factors such as topography and the distribution of resources on land and on the seacoast, taking account of geographical variation and changes in geology, sea levels and palaeoclimate. The merits of northern and southern routes of movement at either end of the Red Sea are compared. All the evidence indicates that there has been no land connection at the southern end since the beginning of the Pliocene period, but that short sea crossings would have been possible at lowest sea-level stands with little or no technical aids. More important than the possibilities of crossing the southern channel is the nature of the resources available in the adjacent coastal zones. There were many climatic episodes wetter than today, and during these periods water draining from the Arabian escarpment provided productive conditions for large mammals and human populations in coastal regions and eastwards into the desert. During drier episodes the coastal region would have provided important refugia both in upland areas and on the emerged shelves exposed by lowered sea level, especially in the southern sector and on both sides of the Red Sea. Marine resources may have offered an added advantage in coastal areas, but evidence for their exploitation is very limited, and their role has been over-exaggerated in hypotheses of coastal colonization

Achieving a quantum smart workforce

Interest in building dedicated Quantum Information Science and Engineering (QISE) education programs has greatly expanded in recent years. These programs are inherently convergent, complex, often resource intensive and likely require collaboration with a broad variety of stakeholders. In order to address this combination of challenges, we have captured ideas from many members in the community. This manuscript not only addresses policy makers and funding agencies (both public and private and from the regional to the international level) but also contains needs identified by industry leaders and discusses the difficulties inherent in creating an inclusive QISE curriculum. We report on the status of eighteen post-secondary education programs in QISE and provide guidance for building new programs. Lastly, we encourage the development of a comprehensive strategic plan for quantum education and workforce development as a means to make the most of the ongoing substantial investments being made in QISE.Comment: 18 pages, 2 figures, 1 tabl