Correspondence between sound propagation in discrete and continuous random media with application to forest acoustics

Although sound propagation in a forest is important in several applications, there are currently no rigorous yet computationally tractable prediction methods. Due to the complexity of sound scattering in a forest, it is natural to formulate the problem stochastically. In this paper, it is demonstrated that the equations for the statistical moments of the sound field propagating in a forest have the same form as those for sound propagation in a turbulent atmosphere if the scattering properties of the two media are expressed in terms of the differential scattering and total cross sections. Using the existing theories for sound propagation in a turbulent atmosphere, this analogy enables the derivation of several results for predicting forest acoustics. In particular, the second-moment parabolic equation is formulated for the spatial correlation function of the sound field propagating above an impedance ground in a forest with micrometeorology. Effective numerical techniques for solving this equation have been developed in atmospheric acoustics. In another example, formulas are obtained that describe the effect of a forest on the interference between the direct and ground-reflected waves. The formulated correspondence between wave propagation in discrete and continuous random media can also be used in other fields of physics

How rare was the august 2016 south-central louisiana heavy rainfall event?

This study examines the spatiotemporal characteristics of the historic 10-14 August 2016 south-central Louisiana precipitation event. The storm was the result of a moisture-rich, tropical low pressure system, also known as a tropical easterly wave, that slowly tracked westward along the Gulf Coast from Florida to Texas. Once over south-central Louisiana, the storm was able to take advantage of anomalously high precipitable water, broad low-level instability, and continuous moisture inflow from the Gulf of Mexico to produce historic rainfall. Totals exceeded 254mm (10 in.) for much of southern Louisiana, while locations adjacent to Baton Rouge and Lafayette received upward of 635mm (25 in.). One station measured a 48-h rainfall total of 797.3mm (31.39 in.)—the greatest 48-h total on record for Louisiana. Using calibrated radar data, the Storm Precipitation Analysis System (SPAS) revealed that one location likely received.864mm (34 in.) of precipitation during the duration of the storm, well over the estimated 1000-yr return interval. A synoptic discussion of the event and analysis of the storm’s recurrence interval helps place this storm in a historical context

The interaction of bacterial pathogens with platelets.

In recent years, the frequency of serious cardiovascular infections such as endocarditis has increased, particularly in association with nosocomially acquired antibiotic-resistant pathogens. Growing evidence suggests a crucial role for the interaction of bacteria with human platelets in the pathogenesis of cardiovascular infections. Here, we review the nature of the interactions between platelets and bacteria, and the role of these interactions in the pathogenesis of endocarditis and other cardiovascular diseases

Subsequent Event Risk in Individuals with Established Coronary Heart Disease:Design and Rationale of the GENIUS-CHD Consortium

BACKGROUND: The "GENetIcs of sUbSequent Coronary Heart Disease" (GENIUS-CHD) consortium was established to facilitate discovery and validation of genetic variants and biomarkers for risk of subsequent CHD events, in individuals with established CHD. METHODS: The consortium currently includes 57 studies from 18 countries, recruiting 185,614 participants with either acute coronary syndrome, stable CHD or a mixture of both at baseline. All studies collected biological samples and followed-up study participants prospectively for subsequent events. RESULTS: Enrollment into the individual studies took place between 1985 to present day with duration of follow up ranging from 9 months to 15 years. Within each study, participants with CHD are predominantly of self-reported European descent (38%-100%), mostly male (44%-91%) with mean ages at recruitment ranging from 40 to 75 years. Initial feasibility analyses, using a federated analysis approach, yielded expected associations between age (HR 1.15 95% CI 1.14-1.16) per 5-year increase, male sex (HR 1.17, 95% CI 1.13-1.21) and smoking (HR 1.43, 95% CI 1.35-1.51) with risk of subsequent CHD death or myocardial infarction, and differing associations with other individual and composite cardiovascular endpoints. CONCLUSIONS: GENIUS-CHD is a global collaboration seeking to elucidate genetic and non-genetic determinants of subsequent event risk in individuals with established CHD, in order to improve residual risk prediction and identify novel drug targets for secondary prevention. Initial analyses demonstrate the feasibility and reliability of a federated analysis approach. The consortium now plans to initiate and test novel hypotheses as well as supporting replication and validation analyses for other investigators

Challenges for adaptation in agent societies

The final publication is available at Springer via http://dx.doi.org/[insert DOIAdaptation in multiagent systems societies provides a paradigm for allowing these societies to change dynamically in order to satisfy the current requirements of the system. This support is especially required for the next generation of systems that focus on open, dynamic, and adaptive applications. In this paper, we analyze the current state of the art regarding approaches that tackle the adaptation issue in these agent societies. We survey the most relevant works up to now in order to highlight the most remarkable features according to what they support and how this support is provided. In order to compare these approaches, we also identify different characteristics of the adaptation process that are grouped in different phases. 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Prognostic value of interleukin-1 receptor antagonist gene polymorphism and cytomegalovirus seroprevalence in patients with coronary artery disease

BACKGROUND: Chronic inflammatory stimuli such as cytomegalovirus (CMV) infection and various genetic polymorphisms determining the inflammatory response are assumed to be important risk factors in atherosclerosis. We investigated whether patients with stable coronary artery disease (CAD) and homozygous for allele 2 of the interleukin 1 receptor antagonist (IL-1RA) gene and seropositive for CMV represent a group particular susceptible for recurrent cardiovascular events. METHODS: In a series of 300 consecutive patients with angiographically defined CAD a prospective follow-up was conducted (mean age 57.9 years, median follow-up time 38.2 months). RESULTS: No statistically significant relationship was found between CMV serostatus and IL-1RN*2 (alone or in combination) and risk for future cardiovascular events (CVE). The hazard ratio (HR) for a CVE given positive CMV-serology and IL-1RN*2 was 1.07 (95% confidence interval (CI) 0.32–3.72) in the fully adjusted model compared to seronegative CMV patients not carrying the IL-1RN*2 allele. In this prospective cohort study involving 300 patients with angiographically defined CAD at baseline, homozygousity for allele 2 of the IL-1 RA and seropositivity to CMV alone and in combination were not associated with an increased risk for cardiovascular events during follow-up; in addition, combination of the CMV-seropositivity and IL-1RN*2 allele were not associated with a proinflammatory response CONCLUSION: Our study suggests that seropositivity to CMV and IL-1RA*2 genotype alone or in combination might not be a strong risk factor for recurrent cardiovascular events in patients with manifest CAD, and is not associated with levels of established inflammatory markers

Antithrombotic Therapy in Patients with Acute Coronary Syndrome in the Intermountain Heart Collaborative Study

Objective. To determine factors associated with single antiplatelet (SAP) or dual antiplatelet (DAP) therapy and anticoagulants (AC) use in hospital and after discharge among patients with acute coronary syndrome (ACS). Methods. We evaluated 5,294 ACS patients in the Intermountain Heart Collaborative Study from 2004 to 2009. Multivariable logistic regressions were used to determine predictors of AC or AP use. Results. In hospital, 99% received an AC, 79% DAP, and 19% SAP; 78% had DAP + AC. Coronary stents were the strongest predictors of DAP use in hospital compared to SAP (P<0.001). After discharge, 77% received DAP, 20% SAP, and 9% AC; 5% had DAP + AC. DAP compared to SAP was less likely for patients on AC (odds ratio [OR] = 0.30, P<0.0001) after discharge. Placement of a stent increased the likelihood of DAP (bare metal: OR = 54.8, P<0.0001; drug eluting: OR = 59.4, P<0.0001). 923 had atrial fibrillation and 337 had a history of venous thromboembolism; these patients had increased use of AC (29% and 40%, resp.). Conclusion. While in-hospital use of AC was nearly universal, postdischarge AC use was rare. Concern for providing the best antithrombotic therapy, while maintaining an acceptable bleeding risk, may explain the selection decisions

Higher docosahexaenoic acid levels lower the protective impact of eicosapentaenoic acid on long-term major cardiovascular events

IntroductionLong-chain omega-3 polyunsaturated fatty acids (OM3 PUFA) are commonly used for cardiovascular disease prevention. High-dose eicosapentaenoic acid (EPA) is reported to reduce major adverse cardiovascular events (MACE); however, a combined EPA and docosahexaenoic acid (DHA) supplementation has not been proven to do so. This study aimed to evaluate the potential interaction between EPA and DHA levels on long-term MACE.MethodsWe studied a cohort of 987 randomly selected subjects enrolled in the INSPIRE biobank registry who underwent coronary angiography. We used rapid throughput liquid chromatography-mass spectrometry to quantify the EPA and DHA plasma levels and examined their impact unadjusted, adjusted for one another, and fully adjusted for comorbidities, EPA + DHA, and the EPA/DHA ratio on long-term (10-year) MACE (all-cause death, myocardial infarction, stroke, heart failure hospitalization).ResultsThe average subject age was 61.5 ± 12.2 years, 57% were male, 41% were obese, 42% had severe coronary artery disease (CAD), and 311 (31.5%) had a MACE. The 10-year MACE unadjusted hazard ratio (HR) for the highest (fourth) vs. lowest (first) quartile (Q) of EPA was HR = 0.48 (95% CI: 0.35, 0.67). The adjustment for DHA changed the HR to 0.30 (CI: 0.19, 0.49), and an additional adjustment for baseline differences changed the HR to 0.36 (CI: 0.22, 0.58). Conversely, unadjusted DHA did not significantly predict MACE, but adjustment for EPA resulted in a 1.81-fold higher risk of MACE (CI: 1.14, 2.90) for Q4 vs. Q1. However, after the adjustment for baseline differences, the risk of MACE was not significant for DHA (HR = 1.37; CI: 0.85, 2.20). An EPA/DHA ratio ≥1 resulted in a lower rate of 10-year MACE outcomes (27% vs. 37%, adjusted p-value = 0.013).ConclusionsHigher levels of EPA, but not DHA, are associated with a lower risk of MACE. When combined with EPA, higher DHA blunts the benefit of EPA and is associated with a higher risk of MACE in the presence of low EPA. These findings can help explain the discrepant results of EPA-only and EPA/DHA mixed clinical supplementation trials

The Myocardial Ischemia Reduction with Acute Cholesterol Lowering trial: MIRACuLous or not, it's time to change current practice

The Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study was the first trial to assess whether statins might be of clinical benefit in those with recently unstable coronary disease. MIRACL found that high-dose atorvastatin was safe and reduced the incidence of the composite endpoint, death, non-fatal myocardial infarction, resuscitated sudden cardiac death or emergent rehospitalization for recurrent ischemia at 16 weeks when compared with placebo. Despite a number of important study limitations, MIRACL's findings and the prior observation that inpatient initiation of lipid-lowering therapy is associated with higher rates of subsequent utilization, suggest that it is prudent to begin statin therapy when patients present with an acute coronary syndrome