Behavior of The Southern Pine Beetle on the Bark of Host Trees During Mass Attack

Twenty-two percent of the southern pine beetles, Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae), that landed on the bark during the 1st 4 days of mass attack in East Texas, eventually entered the tree. Other beetles either flew away (43%), dropped off the host (32%), or were eaten (2%). No significant difference in searching time or distance traveled was found for day of attack or beetle sex. Males spent significantly less total time on the bark than females

Trends in Heart Failure Incidence in the Community: A Gathering Storm

In populations around the world, a gathering storm of cardiovascular disease occurrence is building on the horizon, the likes of which we have not seen in decades. Between 1970 and 2010, age-adjusted cardiovascular mortality rates declined dramatically in almost all Western nations; in many countries, rates fell by ≥70%. However, in 2016, Sidney et al1 reported that in the United States, a substantial deceleration in the decline of all cardiovascular disease, coronary heart disease, and stroke mortality rates began over the past 5 years, signaling a dramatic shift. Prompted by this report, Lloyd-Jones suggested that perhaps we are now just beginning to “reap what we have sown” in the obesity epidemic over the past several decades. It is not a new concept that the Western world’s obesity epidemic can affect population health. What is less well documented is whether the epidemic obesity is beginning to reverse long-standing declines in disease incidence. A recent report from the Centers of Disease Control and Prevention indicates that between 2014 and 2015, age-adjusted death rates in the United States increased for 8 of 10 leading causes of death, including cardiovascular disease rates. Given that heart disease accounts for >30% of all deaths in the United States, the 0.9% increase in age-adjusted mortality from heart disease is of particular concern

A Simple Shell Model for Quantum Dots in a Tilted Magnetic Field

A model for quantum dots is proposed, in which the motion of a few electrons in a three-dimensional harmonic oscillator potential under the influence of a homogeneous magnetic field of arbitrary direction is studied. The spectrum and the wave functions are obtained by solving the classical problem. The ground state of the Fermi-system is obtained by minimizing the total energy with regard to the confining frequencies. From this a dependence of the equilibrium shape of the quantum dot on the electron number, the magnetic field parameters and the slab thickness is found.Comment: 15 pages (Latex), 3 epsi figures, to appear in PhysRev B, 55 Nr. 20 (1997

Earthworms cause furrow infiltration increase

Infiltration rates into furrows in Southern Idaho, after decreasing toward a base rate, often increase. The increase is caused by earthworms piercing the furrow wetted perimeter during the irrigation and water entering and infiltrating from their interconnected burrow systems

A Lanczos algorithm for linear response

An iterative algorithm is presented for solving the RPA equations of linear response. The method optimally computes the energy-weighted moments of the strength function, allowing one to match the computational effort to the intrinsic accuracy of the basic mean-field approximation, avoiding the problem of solving very large matrices. For local interactions, the computational effort for the method scales with the number of particles N_p as O(N_p^3).Comment: 12 pages including 3 figures; Late

Theory of Melting and the Optical Properties of Gold/DNA Nanocomposites

We describe a simple model for the melting and optical properties of a DNA/gold nanoparticle aggregate. The optical properties at fixed wavelength change dramatically at the melting transition, which is found to be higher and narrower in temperature for larger particles, and much sharper than that of an isolated DNA link. All these features are in agreement with available experiments. The aggregate is modeled as a cluster of gold nanoparticles on a periodic lattice connected by DNA bonds, and the extinction coefficient is computed using the discrete dipole approximation. Melting takes place as an increasing number of these bonds break with increasing temperature. The melting temperature corresponds approximately to the bond percolation threshold.Comment: 5 pages, 4 figure. To be published in Phys. Rev.

Strengthening surgical and anaesthetic services at district level in the African region: issues, challenges and proposed actions

Health care delivery systems are organized at several levels with the district hospital serving as the first referral for comprehensive care in the majority of countries worldwide. The provision of comprehensive surgical services requires several inputs and tools to be in place, among which are an adequately trained surgical, anaesthesia and obstetric healthcare workforce, infrastructure and functioning equipment, and essential medicines and supplies. These, however, are not in place in the majority of commonly received surgical cases, such as trauma, obstetric, abdominal and orthopedic emergencies, thus limiting the capacity of district hospitals to address them. Global and regional public health initiatives have traditionally neglected the necessity of the provision of surgical services despite the fact that these constitute an essential component of comprehensive primary healthcare (PHC)1. In fact, because surgery so frequently cannot be safely postponed, this deficiency prevents the transfer of patients to a secondary or tertiarylevel hospital where further care can be provided.

Effect of aerosolized uridine 5′-triphosphate on mucociliary clearance in mild chronic bronchitis

Previous studies show that uridine 5′-triphosphate (UTP), a P2Y2 receptor agonist, is effective at acutely enhancing mucociliary clearance in healthy, nonsmoking adults. UTP solution for inhalation is being developed by Inspire Pharmaceuticals under the compound number INS316. In a double-blind, randomized, crossover, placebo-controlled study we tested the single-dose effect of UTP in chronic smokers with mild chronic bronchitis (n = 15) by measuring the clearance of 99mTc-Fe2O3 particles (4.0 μm mass median aerodynamic diameter [MMAD]) after inhalation of nebulized placebo (0.9% saline) and two doses of UTP (20 and 100 mg in the nebulizer). On each study day, gamma camera scanning was performed over a 2-h period. After an initial deposition scan, subjects inhaled placebo or UTP during the first 20 min of scanning. Analysis of whole lung clearance showed that the retention-time curves for each day were biphasic and that the earliest break point in the average curves occurred at 50 min. Mean particle clearance rate (Clr in %/min) through 50 min for placebo treatment was Clr = 0.65 ± 0.27 whereas treatment with UTP showed Clr significantly increased to 0.95 ± 0.48 and 0.93 ± 0.44 for the 20-mg and 100-mg dose respectively, p &lt0.005 for both as compared with placebo. These data show that mucociliary clearance associated with mild chronic bronchitis is acutely improved with minimal doses of aerosolized UTP, presumably because of its stimulation of ciliary beating and hydration of airway secretions

Dynamics of Excited Electrons in Copper and Ferromagnetic Transition Metals: Theory and Experiment

Both theoretical and experimental results for the dynamics of photoexcited electrons at surfaces of Cu and the ferromagnetic transition metals Fe, Co, and Ni are presented. A model for the dynamics of excited electrons is developed, which is based on the Boltzmann equation and includes effects of photoexcitation, electron-electron scattering, secondary electrons (cascade and Auger electrons), and transport of excited carriers out of the detection region. From this we determine the time-resolved two-photon photoemission (TR-2PPE). Thus a direct comparison of calculated relaxation times with experimental results by means of TR-2PPE becomes possible. The comparison indicates that the magnitudes of the spin-averaged relaxation time \tau and of the ratio \tau_\uparrow/\tau_\downarrow of majority and minority relaxation times for the different ferromagnetic transition metals result not only from density-of-states effects, but also from different Coulomb matrix elements M. Taking M_Fe > M_Cu > M_Ni = M_Co we get reasonable agreement with experiments.Comment: 23 pages, 11 figures, added a figure and an appendix, updated reference

Delivery of Automated External Defibrillators via Drones in Simulated Cardiac Arrest: Users' Experiences and the Human-Drone Interaction

Background: Survival after out-of-hospital cardiac arrest (OHCA) in the United States is approximately 10%. Automatic external defibrillators (AEDs) are effective when applied early, yet public access AEDs are used in <2% of OHCAs. AEDs are often challenging for bystanders to locate and are rarely available in homes, where 70% of OHCAs occur. Drones have the potential to deliver AEDs to bystanders efficiently; however, little is known about the human-drone interface in AED delivery. Objectives: To describe user experiences with AED-equipped drones in a feasibility study of simulated OHCA in a community setting. Methods: We simulated an OHCA in a series of trials with age-group/sex-matched participant pairs, with one participant randomized to search for a public access AED and the other to call a mock 9-1-1 telephone number that initiated the dispatch of an AED-equipped drone. We investigated user experience of 17 of the 35 drone recipient participants via semi-structured qualitative interviews and analyzed audio-recordings for key aspects of user experience. Results: Drone recipient participants reported largely positive experiences, highlighting that this delivery method enabled them to stay with the victim and continue cardiopulmonary resuscitation. Concerns were few but included drone arrival timing and direction as well as bystander safety. Participants provided suggestions for improvements in the AED-equipped drone design and delivery procedures. Conclusion: Participants reported positive experiences interacting with an AED-equipped drone for a simulated OHCA in a community setting. Early findings suggest a role for drone-delivered AEDs to improve bystander AED use and improve outcomes for OHCA victims