What inspires birders to migrate South towards Africa? A quantitative measure of international avitourist motivation

Despite the rapid growth of avitourism (birding) globally, the international market potential of avitourism is not fully utilised. This research endeavoured to develop a multidimensional measure of avitourist motivation and to investigate the relative importance of the different dimensions or factors of avitourist motivation. Based on an in-depth review of the literature, a measure of birder motivation was developed. The research instrument was evaluated by a group of birding experts. The instrument was further evaluated and refined based on primary data gathered from 439 visitors to the British Birdwatching Fair and the Dutch Vogelfestival. Confirmatory factor analysis was used to evaluate the dimensionality and fit of the instrument based on the proposed factorial structure. Finally, a second-order confirmatory factor analysis model for avitourist motivation revealed higher-order constructs, namely wellbeing, intellectual activity, social interaction and photography. The results suggest that the photography dimension could be excluded as a motivational factor, and that birders consider aspects of wellbeing (emotional, spiritual, physical and mental stimulation) as the most important factors that motivate birding.Keywords: avitourism (birding tourism), bird fairs, travel motivations, second-orderconfirmatory factor analysi

Two-dimensional boson-fermion mixtures

Using mean-field theory, we study the equilibrium properties of boson-fermion mixtures confined in a harmonic pancake-shaped trap at zero temperature. When the modulus of the s-wave scattering lengths are comparable to the mixture thickness, two-dimensional scattering events introduce a logarithmic dependence on density in the coupling constants, greatly modifying the density profiles themselves. We show that for the case of a negative boson-fermion three-dimensional s-wave scattering length, the dimensional crossover stabilizes the mixture against collapse and drives it towards spatial demixing.Comment: 9 pages, 4 figure

Difference schemes of high order accuracy for mathematical physics problems in arbitrary domains

In the present paper the difference schemes of high order accuracy for two‐dimensional equations of mathematical physics in an arbitrary domain are constructed. The computational domain is covered by a uniform rectangular grid. The second order accuracy of local approximation by spatial variables is achieved near‐boundary nodes. No increase of a standard grid scheme template is required. A priori estimates of the stability are obtained. Didelio tikslumo baigtinių skirtumų schemos Santrauka Darbe nagrinejami matematines fizikos uždaviniai, kai apibrežimo srities kontūras yra bet kokia glodi uždara kreive. Ši sritis pakeičiama tolygiu stačiakampiu tinklu. Panaudojant specialias aproksimavimo formules ir pasienio taškuose aproksimacijos paklaidos eile yra antroji. Svarbi naujojo algoritmo savybe yra tai, kad visuose taškuose naudojamas toks pat diskrečiojo tinklo šablonas. Irodomi aprioriniai stabilumo iverčiai ir ivertinamas diskrečiojo sprendinio konvergavimo greitis. Pateikti skaičiavimo eksperimento, kuriame naujoji schema palyginama su dviem kitomis žinomomis baigtiniu skirtumu schemomis, rezultatai. First Published Online: 14 Oct 201

Stream-field interactions in the magnetic accretor AO Piscium

UV spectra of the magnetic accretor AO Psc show absorption features for half the binary orbit. The absorption is unlike the wind-formed features often seen in similar stars. Instead, we attribute it to a fraction of the stream that overflows the impact with the accretion disk. Rapid velocity variations can be explained by changes in the trajectory of the stream depending on the orientation of the white-dwarf's magnetic field. Hence we are directly observing the interaction of an accretion stream with a rotating field. We compare this behavior to that seen in other intermediate polars and in SW Sex stars.Comment: Accepted for ApJ; 6 page

Simulations of Spinodal Nucleation in Systems with Elastic Interactions

Systems with long-range interactions quenched into a metastable state near the pseudospinodal exhibit nucleation that is qualitatively different than the classical nucleation observed near the coexistence curve. We have observed nucleation droplets in our Langevin simulations of a two-dimensional model of martensitic transformations and have determined that the structure of the nucleating droplet differs from the stable martensite structure. Our results, together with experimental measurements of the phonon dispersion curve, allow us to predict the nature of the droplet. These results have implications for nucleation in many solid-solid transitions and the structure of the final state

Tuberculosis infection control in a South African rural regional hospital emergency centre: Prioritisation for patients and healthcare workers

South Africa (SA) is in the midst of a tuberculosis (TB) epidemic and has one of the highest TB incidence rates globally. Despite increasing global commitment to eliminate TB, SA appears to be falling behind in this regard. This article examines key challenges to effective TB infection control from a rural regional hospital perspective. It uses the Eden District in Western Cape Province as an example to share lessons learnt. This quality-improvement project identifies four priorities for improving TB infection control in George Hospital and the Eden District: (i) prioritising TB infection control in local policy; (ii) improving the quality of TB screening in the emergency centre; (iii) increasing the number of TB patients followed up; and (iv) implementing TB infection control training for all staff. This project demonstrates the role of an emergency centre in TB screening, highlighting that this should not only be a priority for primary care, but also for secondary and tertiary care. Simple interventions, such as training of local healthcare workers in TB infection control and good-quality TB screening, can initiate a behavioural change. It also stresses the importance of good communication and co-ordination of care across primary and secondary care, ensuring that patients are not lost to follow-up. Local policy needs to reflect these straightforward interventions, empowering local healthcare workers and managers to increase responsibility and accountability for TB infection control.TB is preventable, and infection control needs to become a priority throughout SA primary, secondary and tertiary care. This project highlights that simple interventions, such as engaging local healthcare workers in a co-ordinated multisystem and multidisciplinary approach, could help to reduce the number of missing TB cases and bring SA’s TB epidemic under control

Draft genome sequences of <i>Pantoea agglomerans</i> and <i>Pantoea vagans</i> isolates associated with termites

The genus Pantoea incorporates many economically and clinically important species. The plant-associated species, Pantoea agglomerans and Pantoea vagans, are closely related and are often isolated from similar environments. Plasmids conferring certain metabolic capabilities are also shared amongst these two species. The genomes of two isolates obtained from fungus-growing termites in South Africa were sequenced, assembled and annotated. A high number of orthologous genes are conserved within and between these species. The difference in genome size between P. agglomerans MP2 (4,733,829 bp) and P. vagans MP7 (4,598,703 bp) can largely be attributed to the differences in plasmid content. The genome sequences of these isolates may shed light on the common traits that enable P. agglomerans and P. vagans to co-occur in plant- and insect-associated niches.The Danish Council for Independent Research, Natural Sciences (STENO grant: Michael Poulsen), the National Research Foundation (NRF) (RCA Fellowship: Pieter De Maayer) and the NRF/Dept. of Science and Technology Centre of Excellence in Tree Health Biotechnology (CTHB), South Africa.http://www.standardsingenomics.org/index.php/sigenam2016Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant Patholog

The effect of pinholes of different sizes on visual acuity under different refracting states and ambient lighting conditions*

Purpose: The purpose of this pilot study was to investigate the effect of different size pinholes on visual acuity (VA) at near (0.4 m) while various factors were altered. The alterations made involved accommodation and illumination. Method: Four subjects were selected and their ages ranged from 7 to 14 years. Subjective refractions were performed and then near visual acuities were measured at 0.4 m under two different lighting conditions (460 lux and 1 lux) by adding stigmatic (or spherical) lenses of positive and negative powers in front of pinholes of diameters 1.5 mm and 2 mm. Results: The results showed that there was an improvement in VA in most, however, the size of the pinhole played a minor role. Low illumination did have a drastic effect on our results not only by decreasing the amount of lenses used for near that gave more positive results, but also when the pinhole was placed in front of the subjects. According to Borish, the pinhole does improve VA by a straight forward process of elimination produced by spherical aberrations of the eye. However, this did not seem to be the case in this study under conditions of low illumination. Conclusion: The pinhole effect offers improvement in VA at near by reducing the amount of blupresented to the retina. This study showed that alsubjects had an improvement in VA of at least two lines in high illumination. Pinhole size did not alte the results sufficiently thus suggesting that a pinhole, no matter the size, should increase the VA. However this was not the case when illumination was decreased

A prospective observational study of preoperative natriuretic peptide testing in adult non-cardiac surgical patients in hospitals in Western Cape Province, South Africa

Background. International guidelines recommend risk stratification to identify high-risk non-cardiac surgical patients. It is also recommended that all patients aged ≥45 years with significant cardiovascular disease should have preoperative natriuretic peptide (NP) testing. Abnormal preoperative B-type NPs have a strong association with postoperative cardiac complications. In South African hospitals, it is not known how many patients with significant cardiovascular disease scheduled for intermediate- to high-risk surgery will have raised NPs.Objectives. To determine the prevalence of abnormal (raised) NPs in non-cardiac surgical patients with cardiac clinical risk factors. A secondary objective was to develop a model to identify surgical patients who may benefit from preoperative NP screening.Methods. The inclusion criteria were patients aged ≥45 years presenting for elective, non-obstetric, intermediate- to high-risk non-cardiac surgery with at least one of the following cardiovascular risk factors: a history of ischaemic heart disease or peripheral vascular disease (coronary equivalent); a history of stroke or transient ischaemic attack; a history of congestive cardiac failure; diabetes mellitus currently on an oral hypoglycaemic agent or insulin; and serum creatinine level &gt;175 µmol/L (&gt;2.0 mg/dL). Blood samples for N-terminal-prohormone B-type NP (NT-proBNP) were collected before induction of anaesthesia. The preoperative prognostic threshold for abnormal (raised) NT-proBNP was ≥300 pg/mL. A generalised linear mixed model was used to determine the association between the risk factors and an abnormal NT-proBNP level.Results. Of 172 patients, 63 (37%) had an elevated preoperative NT-proBNP level. The comorbidities independently associated with elevated preoperative NT-proBNP were coronary artery disease or peripheral vascular disease, congestive cardiac failure, diabetes mellitus, and a creatinine level &gt;175 µmol/L.Conclusions. We strongly recommend that non-cardiac surgical patients aged ≥45 years undergoing intermediate- or high-risk non-cardiac surgery with a history of coronary artery disease/peripheral vascular disease, congestive cardiac failure, diabetes mellitus or elevated creatinine have preoperative NP testing as part of risk stratification

Harmonically trapped fermion gases: exact and asymptotic results in arbitrary dimensions

We investigate the particle and kinetic energy densities of harmonically trapped fermion gases at zero temperature in arbitrary dimensions. We derive analytically a differential equation connecting these densities, which so far have been proven only in one or two dimensions, and give other interesting relations involving several densities or the particle density alone. We show that in the asymptotic limit of large particle numbers, the densities go over into the semi-classical Thomas-Fermi (TF) densities. Hereby the Fermi energy to be used in the TF densities is identified uniquely. We derive an analytical expansion for the remaining oscillating parts and obtain very simple closed forms for the leading-order oscillating densities. Finally, we show that the simple TF functional relation $\tau_{TF}[\rho]$ between kinetic and particle density is fulfilled also for the asymptotic quantum densities $\tau(r)$ and $\rho(r)$ including their leading-order oscillating terms.Comment: LaTeX, 22 pages with 6 figures (*.eps), to be submitted to J. Phys.