Selection of a Realistic Viscous Vortex Tangential Velocity Profile for Computer Simulation of Vortex-Structure Interaction

Structure loading by vortices is a relevant phenomenon in numerous fields of engineering significance. Computer modelling is a powerful tool that can be used to study the loading produced on structures by impacting vortices. Realistic simulation of vortex-loading of structures necessitates the use of a realistic vortex tangential velocity profile (TVP). The present study compiles measured TVPs from various types of experimentally-produced vortices as well as real-world tornado and hurricane vortices. The measured TVPs are compared with commonly-used, analytical TVPs. Analytical TVPs that realistically represent the range of measured TVPs are identified and selected for use in future computer simulation studies

1420 MHz Continuum Absorption Towards Extragalactic Sources in the Galactic Plane

We present a 21-cm emission-absorption study towards extragalactic sources in the Canadian Galactic Plane Survey (CGPS). We have analyzed HI spectra towards 437 sources with S > 150 mJy, giving us a source density of 0.6 sources per square degree at arcminute resolution. We present the results of a first analysis of the HI temperatures, densities, and feature statistics. Particular emphasis is placed on 5 features with observed spin temperatures below 40 K. We find most spin temperatures in the range from 40 K to 300 K. A simple HI two-component model constrains the bulk of the cold component to temperatures (T_c) between 40 K and 100 K. T_c peaks in the Perseus arm region and clearly drops off with Galactocentric radius, R, beyond that. The HI density follows this trend, ranging from a local value of 0.4 cm^{-3} to less than 0.1 cm^{-3} at R = 20 kpc. We find that HI emission alone on average traces about 75% of the total HI column density, as compared to the total inferred by the emission and absorption. Comparing the neutral hydrogen absorption to CO emission no correlation is found in general, but all strong CO emission is accompanied by a visible HI spectral feature. Finally, the number of spectral HI absorption features per kpc drop off exponentially with increasing R.Comment: 13 pages, 13 figures, Accepted for March 2004 Ap

Immune consequences of exercise in hypoxia: A narrative review.

Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type, dose (frequency/duration, intensity), and individual characteristics. Similarly, reduced availability of ambient oxygen (hypoxia) modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia. How combined exercise and hypoxia (e.g., high-altitude training) sculpts immune responses is not well understood, although such combinations are becoming increasingly popular. Therefore, in this paper, we summarize the impact on immune responses of exercise and of hypoxia, both independently and together, with a focus on specialized cells in the innate and adaptive immune system. We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia, then we discuss how they may be modulated by nutritional strategies. Mitochondrial, antioxidant, and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism, resilience, and overall immune functions by regulating the survival, differentiation, activation, and migration of immune cells. This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions. Appropriate acclimatization, training, and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state

A mapping approach to synchronization in the "Zajfman trap": stability conditions and the synchronization mechanism

We present a two particle model to explain the mechanism that stabilizes a bunch of positively charged ions in an "ion trap resonator" [Pedersen etal, Phys. Rev. Lett. 87 (2001) 055001]. The model decomposes the motion of the two ions into two mappings for the free motion in different parts of the trap and one for a compressing momentum kick. The ions' interaction is modelled by a time delay, which then changes the balance between adjacent momentum kicks. Through these mappings we identify the microscopic process that is responsible for synchronization and give the conditions for that regime.Comment: 12 pages, 9 figures; submitted to Phys Rev

Structure of sufficient quantum coarse-grainings

Let H and K be Hilbert spaces and T be a coarse-graining from B(H) to B(K). Assume that density matrices D_1 and D_2 acting on H are given. In the paper the consequences of the existence of a coarse-graining S from B(K) to B(H) satisfying ST(D_1)=D_1 and ST(D_2)=D_2 are given. (This condition means the sufficiency of T for D_1 and D_2.) Sufficiency implies a particular decomposition of the density matrices. This decomposition allows to deduce the exact condition for equality in the strong subadditivity of the von Neumann entropy.Comment: 13 pages, LATE

Evaluating the clinical management of severely malnourished children--a study of two rural district hospitals.

BACKGROUND: Severe malnutrition is an important cause of preventable mortality in most South African hospitals. Work recently done in two rural Eastern Cape hospitals supports the literature which shows that many deaths occur as a result of outdated clinical practices and that improving these practices reduces case fatality rates. Rapid assessment of clinical management in paediatric wards is necessary to highlight areas for improvement. OBJECTIVE: To assess the management of severely malnourished children in two rural district hospitals and to recommend improvements for their care. METHODS: Based on draft World Health Organisation (WHO) guidelines for inpatient care of children with severe malnutrition, data collection instruments were developed in conjunction with the district nutrition team to assess the quality of care given to malnourished children in two Mount Frere hospitals, Eastern Cape. Data were collected through retrospective review of case records, with detailed studies of selected cases, structured observations of the paediatric wards, and interviews with ward sisters and doctors. RESULTS: The combined case fatality rate for severe malnutrition was 32%. Inadequate feeding, poor management of rehydration and infection, lack of resources, and a lack of knowledge and motivation among staff were identified as areas that need attention. CONCLUSION: The clinical management of severely malnourished children can be rapidly assessed to highlight areas for improvement. Involving staff in the assessment process has led to their active involvement in improving the management of malnourished children in their hospitals

Rapid synthesis of supported single metal nanoparticles and effective removal of stabilizing ligands

A method is introduced to rapidly (<30 min) synthesize single metal nanoparticles with narrow size distribution in a simple way. It is based on the electrospraying of a metal precursor solution into a surfactant solution, which acts as a reducing and stabilizing agent. This synthesis method is demonstrated for the production of Ag and Au nanoparticles, which are incorporated onto carbonaceous and non-carbonaceous supports. The nanoparticle size depends on the internal diameter of the spraying nozzle. The removal of the stabilizing surfactant (dodecylamine; DDA) is also examined via thermal annealing and oxygen plasma treatments. Thermal annealing at a low temperature rate is found to be the most effective, as it completely removes DDA from the metal nanoparticles without inducing changes in their particle size. To verify that the supported Ag nanoparticles post calcination are surfactant-free and, thus, their surface sites are active, their oxygen reduction reaction (ORR) activity is measured in alkaline media, demonstrating similar values to the ones reported in the literature

Nasal administration of diacetylmorphine improved the adherence in a patient receiving heroin-assisted treatment

Background: Traditional heroin-assisted treatment in Switzerland consists of oral and injectable diacetylmorphine (pharmaceutical heroin) administration. To date, no suitable treatment option is available for patients who crave rapid onset (“rush”) but are either unable to inject or primarily sniff or inhale illicit heroin. We present a patient who successfully switched to intranasal heroin-assisted treatment following several unsuccessful treatment attempts. Case presentation: A 29-year-old male with severe opioid use disorder, injection substance use, and concomitant cocaine use, previously prescribed slow-release oral morphine, was started on intravenous diacetylmorphine. Due to complications and harms associated with intravenous injections, nasal diacetylmorphine was prescribed. With this novel route of administration, the patient who had previously been unable to adhere to other OAT options remained in treatment. Health outcomes improved by reduction of injection-related harms, increased adherence to the heroin-assisted treatment regimen, and increased collaboration with the therapeutic staff. Conclusions: Nasal heroin-assisted treatment can be a feasible therapeutic option for individuals with severe opioid use disorder who crave the fast onset of effect of diacetylmorphine but are unable to inject intravenously