Electronic band structure of calcium oxide

We employed electron momentum spectroscopy (EMS) to measure the bulk electronic structure of calcium oxide. We extracted the electron momentum density (EMD), density of occupied states (DOS), band dispersions, bandwidths and intervalence bandgaps from the data. The results are compared with calculations based on the full potential linear muffin-tin orbital(FP-LMTO) approximation. While the bandwidths of 0.6±0.2 and 1.2±0.1 eV for the s- and p-bands, respectively, and their dispersions agree well with the LMTO calculation, the relative intensity of the two bands is at odds with the theory. The measured intervalence bandgap at the Γ-point of 16.5±0.2 eV is larger by 2.1 eV than that from the LMTO calculation. The experimental bandwidth of the Ca 3p semi-core level of 0.7±0.1 eV agrees with the LMTO prediction. The measured bandgap between this level and the s-band is 3.6±0.2 eV. The Ca 3s-3p level splitting is in excellent agreement with the literature. © 2004 Elsevier B.V. All rights reserved

The Transition from Heavy Fermion to Mixed Valence in Ce1-xYxAl3: A Quantitative Comparison with the Anderson Impurity Model

We present a neutron scattering investigation of Ce1-xYxAl3 as a function of chemical pressure, which induces a transition from heavy-fermion behavior in CeAl3 (TK=5 K) to a mixed-valence state at x=0.5 (TK=150 K). The crossover can be modeled accurately on an absolute intensity scale by an increase in the k-f hybridization, Vkf, within the Anderson impurity model. Surprisingly, the principal effect of the increasing Vkf is not to broaden the low-energy components of the dynamic magnetic susceptibility but to transfer spectral weight to high energy.Comment: 4 pages, 5 figure

The role of convection in stellar models

This thesis reviews the essential ingredients of local, time-independent mixing-length theory, the convective stability of uid elements in the stellar interior, the origins and in uence of convection zones in stars, and the numerical implementation of convection in some popular stellar evolution codes. The thesis concludes with a brief discussion of the future role of mixing-length theory in stellar modelling

Communications Biophysics

Contains reports on six research projects.U. S. Air Force under Contract AF19(604)-4112

Refining prediction accuracy for pest blackfly outbreaks using Bayesian networks, Orange River, Northern Cape, South Africa.

Master of Science in Geography. University of KwaZulu-Natal, Pietermaritzburg, 2018Construction of dams, impoundments and Inter-Basin Transfer schemes (IBTs) along the Orange River are aimed to provide useable water for multiple sectors. However, operation of these water schemes had led to changes in flow regimes, seston concentrations and water temperatures, which has led to an escalation of pest blackfly (S.chutteri) outbreaks along the lower to middle reaches of the Orange River. Pest blackfly bite livestock, poultry and humans asthey require a blood meal to complete ovarian development. During outbreak periods, livestock farming and the grape industries are affected negatively by pest blackflies along the Orange River. The blackfly control programme has been operating for over twenty years, and aims to control blackfly outbreaks by applying larvicides along the Orange River. Although this programme is in place, periodic outbreaks occur and losses in livestock and productivity can amount to an estimated R300 million during an outbreak (2013). Therefore, other methods should need to be integrated with this programme to achieve blackfly control. Predictive modelling was identified as a method to assist the blackfly problem. Being able to predict when, where and the severity of an outbreak, will assist management in control planning. Bayesian network (Bn) models were identified as a suitable predictive model,as multiple variables can be used in understanding the cause and effects of a response variable.The aim of the research was to refine prediction accuracy of blackfly outbreaks along the middle to lower reaches of the Orange River, using Bns. Fourteen sites were sampled along the Orange River, for which abiotic and biotic data were collected during four sampling periods. These data were used in assisting quantitative components of the Bns, whilst the qualitative components were based of previous Bns with additions on new nodes that were identified as affecting blackfly outbreaks. Water temperature data showed that sites were split into two distinct groupings, for which Bns were constructed.These were termed the upper and lower stream models. The upper stream model had the higher outbreak probabilities, whilst it was predicted for both models that summer would be the season most likely for an outbreak to occur. The species most likely to cause an outbreak was identified to be either S.chutteri or S.damnosum, with switching in dominance throughout sampling periods potentially due to switching in seston concentrations. Future outbreak probabilities based on scenarios of increased discharge and water temperatures indicate that the blackfly problem is likely to worsen, with increases in discharge resulting in greater habitat availability for pest species and increases in water temperature resulting in shorter life cycles and more rapid reproduction.The Bns constructed show promise in assisting management as blackfly outbreak probabilities were refined on a spatial and temporal scale along the middle to lower reaches of the Orange River

The effectiveness of long-term psychoanalytic therapy: A systematic review of empirical studies.

Background: There is a gap in the research literature on the effectiveness of long-term psychoanalytic therapies (LPT). Aim: To present a systematic review of studies dealing with LPT effectiveness and published from 1970 onward. Methods: A systematic literature search for studies dealing with the effectiveness of individual LPT in ambulatory, adult patients. Data about the overall effectiveness of LPT, its impact on symptom reduction, and its effect on personality changes were pooled both at treatment termination and at follow-up, using effect sizes (ESs) and success rates. Results:We found 27 studies (n= 5063). Psychotherapy yielded large mean ESs (0.78 at termination; 0.94 at follow-up) and high mean overall success rates (64% at termination; 55% at follow-up) in moderate/mixed pathology. The mean ES was larger for symptom reduction (1.03) than for personality change (0.54). In severe pathology, the results were similar. Psychoanalysis achieved large mean ESs (0.87 at termination; 1.18 at follow-up) and high mean overall success rates (71% at termination; 54% at follow-up) in moderate pathology. The mean ES for symptom reduction was larger (1.38) than for personality change (0.76). Conclusion: Our data suggest that LPT is effective treatment for a large range of pathologies, with moderate to large effects. (HARV REV PSYCHIATRY 2009;17:1–23.

Seventeen-year outcome of surgical management of severe early onset kyphoscoliosis in a patient with arthrochalasia-type Ehlers-Danlos

We report on the surgical management of severe early onset kyphoscoliosis in a 5-year-old patient with the rare arthrochalasia subtype of Ehlers–Danlos syndrome, who we have followed for 17 years post-operatively. Successful correction of the deformity with an excellent outcome was achieved with minimal morbidity using MAGEC™ (MAGnetic Expansion Control) growth rods instead of traditional growth rods, undertaken with the close involvement of plastic surgical colleagues. Our patient suffered only one minor surgical complication (thought to be allergic rather than traumatic in origin), despite having skin so fragile that rubbing his skin with a disinfectant wipe was sufficient to cause skin breakdown. The non-invasive lengthening that the MAGEC rods allowed enabled us to avoid repeated open surgeries which would have had a high risk of complications, most notably wound breakdown with poor healing, and we advocate their use in similar cases