The regional employment impacts of renewable energy expenditures: The case for modelling

One aspect of the case for policy support for renewable energy developments is the wider economic benefits that are expected to be generated. Within Scotland, as with other regions of the UK, there is a focus on encouraging domesticallyâ€based renewable technologies. In this paper, we use a regional computable general equilibrium framework to model the impact on the Scottish economy of expenditures relating to marine energy installations. The results illustrate the potential for (considerable) ‘legacy’ effects after expenditures cease. In identifying the specific sectoral expenditures with the largest impact on (lifetime) regional employment, this approach offers important policy guidance.Renewable energy policy; regional economic impacts; computable general equilibrium modelling.

HIV-1 Subtype B and C Envelope Glycoprotein based immunogens as preventative vaccines

A thesis submitted to Faculty of Health Sciences, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg, September 2017.The ability to induce a potent and broadly neutralizing antibody (bNAb) response following vaccination is critical in developing an effective HIV-1 vaccine. To date, no HIV-1 envelope glycoprotein (Env) immunogens have elicited bNAbs in preclinical or human clinical trials. This study compared the antigenicity and immunogenicity of a panel of HIV-1 subtype B and C Env-based immunogens in various immunization regimens in a small animal model. The Env-based immunogens used included matched monomeric (gp120) and trimeric (gp140GCN4(+)) conformations of 6 subtype C Env’s (IN26191, IN25710, IN25925, ZACAP45, ZACAP210 and ZA706010164; all designed during the course of this study), and subtype B stabilized Env derivatives Cyc4OD gp120 cyclic permutant, gp140 cyclic permutant h-CMP V1cyc 144-142, ODECCOBPICS gp120 fragment, VRC01 engrafted scaffold peptides 1WR2 and 1ORC, and DNA (Wt-JRFL-Env, JRFL Env-570D and JRLF Env-SEKS; all obtained from collaborators). The six HIV-1 subtype C Env sequences (IN26191, IN25710, IN25925, ZACAP45, ZACAP210 and ZA706010164) were selected, matched gp120 and gp140GCN4(+) constructs were designed, codon optimized and cloned into a mammalian expression vector. All 12 env constructs were expressed in HEK293T or 293FS cell lines, and the Env purified by lectin affinity chromatography, followed by size exclusion chromatography. Additionally, two domain soluble CD4 (2dCD4) wildtype, folding defective and an S60C mutant were expressed in a bacterial system and purified by nickel affinity chromatography. 2dCD4S60C-liganded Env was prepared, and purified further, as required. The antigenicity of all 12 Env’s was evaluated against 2dCD4 and a panel of bNAbs using surface plasmon resonance (SPR). The immunogenicity of two of these subtype C Env variants (liganded and unliganded to 2dCD4S60C) were subsequently compared to that of the subtype B immunogens in rabbits, using various prime-boost regimens. Rabbit sera were subsequently tested for anti-Env binding antibody titres by enzyme linked immunosorbent assay (ELISA), and neutralization by an in vitro phenotypic neutralization assay against a panel of HIV-1 pseudoviruses. All 12 recombinant Envs were successfully expressed and purified to homogeneity. Binding of all the gp120/gp140GCN4(+) Env variants to 2dCD4 variants (Wt and S60C) confirmed that they were all functional and conformationally intact with an accessible CD4 binding site (CD4bs). Binding to a panel of CD4bs directed bNAbs (IgG1b12, VRC01, HJ16, VRC-CH31, NIH45-46G54W, VRC03) revealed that overall, the trimeric gp140GCN4(+) variants showed higher binding affinities to these bNAbs compared to the matched monomeric gp120, attributed to their resemblance to the native trimer on the viral surface. With the exception of VRC03 and IgG1b12, the Indian Env variants bound with an approximately 10-fold higher affinity compared to the South African Env’s. Overall, nine different immunization regimens were performed. Immunization of rabbits induced high titres of antibodies (Abs) for all the immunogens tested, as determined by ELISA, however, minimal neutralization breadth (against Tier 1 pseudoviruses) was obtained for the Env-only variants for subtype B and C immunogens. Of these, the VRC01 engrafted scaffold peptide (1ORC) showed improved neutralization of the Tier 1 pseudovirus SF162 compared to the other Env only based immunogens. The only promising neutralization results were obtained from rabbits immunized with the Env/2dCD4S60C liganded immunogens that potently neutralized both subtype B and C, Tier 1, 2 and 3 pseudoviruses. This response was improved for the trimeric Env/2dCD4S60C complexes compared to the monomeric ones and was consistently elicited regardless of the Env sequence used. The neutralization response is likely either due to Abs targeting one or more epitopes on 2dCD4 or Env or both. Therefore, the use of CD4 liganded Env immunogens in vaccine design should be investigated further as they provide a promising “Ibalizumab-like” neutralization response. Overall, based on emerging evidence on how the bNAb responses evolve in HIV-1 infected individuals, the findings in this study are promising and lay the groundwork for further testing of these HIV-1 Env based immunogens in various combinations using sequential prime-boost strategies to optimally drive affinity maturation of the appropriate B cell lineages.LG201

Effect of 405 nm high-intensity narrow-spectrum light on osteoblast function

A significant portion of medical devices fail due to acquired infection, with infection rates after arthroplasty surgery between 1-4%, and considerably higher after revision surgery. To reduce the associated costs of infection, a new preventative method is required. High intensity narrow spectrum (HINS) 405 nm light is a new technology shown to have bactericidal effects on a range of medically important bacteria[1]. The effect of HINS-light on osteoblasts and bacteria were investigated to determine the potential of this technology to contribute to infection prevention in operating theatres, during surgery and postoperative dressing changes

Mild acute stress improves response speed without impairing accuracy or interference control in two selective attention tasks: Implications for theories of stress and cognition.

Acute stress is generally thought to impair performance on tasks thought to rely on selective attention. This effect has been well established for moderate to severe stressors, but no study has examined how a mild stressor-the most common type of stressor-influences selective attention. In addition, no study to date has examined how stress influences the component processes involved in overall selective attention task performance, such as controlled attention, automatic attentional activation, decision-making, and motor abilities. To address these issues, we randomly assigned 107 participants to a mild acute stress or control condition. As expected, the mild acute stress condition showed a small but significant increase in cortisol relative to the control condition. Following the stressor, we assessed attention with two separate flanker tasks. One of these tasks was optimized to investigate component attentional processes using computational cognitive modeling, whereas the other task employed mouse-tracking to illustrate how response conflict unfolded over time. The results for both tasks showed that mild acute stress decreased response time (i.e., increased response speed) without influencing accuracy or interference control. Further, computational modeling and mouse-tracking analyses indicated that these effects were due to faster motor action execution time for chosen actions. Intriguingly, however, cortisol responses were unrelated to any of the observed effects of mild stress. These results have implications for theories of stress and cognition, and highlight the importance of considering motor processes in understanding the effects of stress on cognitive task performance

405 nm light exposure of osteoblasts and inactivation of bacterial isolates from arthroplasty patients : potential for new disinfection applications?

Infection rates after arthroplasty surgery are between 1-4 %, rising significantly after revision procedures. To reduce the associated costs of treating these infections, and the patients' post-operative discomfort and trauma, a new preventative method is required. High intensity narrow spectrum (HINS) 405 nm light has bactericidal effects on a wide range of medically important bacteria, and it reduced bacterial bioburden when used as an environmental disinfection method in a Medical Burns Unit. To prove its safety for use for environmental disinfection in orthopaedic theatres during surgery, cultured osteoblasts were exposed to HINS-light of intensities up to 15 mW/cm2 for 1 h (54 J/cm2). Intensities of up to 5 mW/cm2 for 1 h had no effect on cell morphology, activity of alkaline phosphatase, synthesis of collagen or osteocalcin expression, demonstrating that under these conditions this dose is the maximum safe exposure for osteoblasts; after exposure to 15 mW/cm2 all parameters of osteoblast function were significantly decreased. Viability (measured by protein content and Crystal Violet staining) of the osteoblasts was not influenced by exposure to 5 mW/cm2 for at least 2 h. At 5 mW/cm2 HINS-light is an effective bactericide. It killed 98.1 % of Staphylococcus aureus and 83.2 % Staphylococcus epidermis populations seeded on agar surfaces, and is active against both laboratory strains and clinical isolates from infected hip and knee arthroplasties. HINS-light could have potential for development as a method of disinfection to reduce transmission of bacteria during arthroplasty, with wider applications in diverse surgical procedures involving implantation of a medical device. With kind permission of full reproduction from eCM journal (www.ecmjournal.org). Founded by scientists for the benefit of Science rather than profit

The development and evaluation of Baculovirus formulations for the biological control of the African cotton bollworm

Wettable powder and suspension formulations of a Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearSNPV) biopesticide were developed for the control of the African cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae). Greenhouse trials of an unformulated suspension of HearSNPV were conducted on tomato plants artificially infested with H. armigera larvae to determine the efficacy of the virus without formulation additives. Two greenhouse trials were carried out. An application rate of 1.00 x 1013 occlusion bodies per hectare (OBs/ha) significantly reduced the number of larvae per plant compared to the control group in greenhouse trial 1, and application rates ranging between 4.80 x 1011 to 4.80 x 1012 OBs/ha significantly reduced the number of larvae compared to the control group in greenhouse trial 2. In terms of pest reduction, the HearSNPV treatments in greenhouse trial 2 were comparable to a commercially available biopesticide (Dipel, containing Bacillus thuringiensis). The effect of the purity, in terms of bacterial contamination, of the inoculum used to infect H. armigera insects was compared at three different storage temperatures (4, 25 and 37 °C) for three different storage periods (7, 30 and 90 days). No significant difference was found between the bacterial counts of the homogenates prior to storage. However, the total bacterial aerobic counts increased on storage and were highest for homogenates prepared from the crude inoculum which averaged 5.16 log cfu/mg, compared to 3.92 log cfu/mg and 2.90 log cfu/mg for the purified and control (sterile distilled water) inoculums respectively. The contaminating bacteria were identified using 16S rDNA sequence analysis, and found to be a Bacillus and Enterococcus species. This suggests that bacterial contamination should be minimized from the start of baculovirus production, since the microbial load can increase on storage. Additives, namely Instant Starch (IS) and Xanthan Gum (XG) were used to prepare HearSNPV suspensions and these were evaluated under accelerated storage conditions, corresponding to storage at room temperature for two years. The IS suspension completely lost its insecticidal activity after storage, while the XG and Unformulated (UF) suspensions were 4.8 and 3 times respectively, less insecticidal after storage. The microbial load decreased from an initial total aerobic count of 8.0 log cfu/ml each, to 3.24 log cfu/ml, 6.86 log cfu/ml and 4.26 log cfu/ml for the IS, UF and XG suspensions respectively. Two bacterial genera were isolated from these samples, namely Bacillus and Paenibacillus. The pH of the suspensions remained near neutral, with the exception of the IS suspension, which had a pH of approximately 3.5 after storage. The XG suspension displayed the best stability on storage, followed by the UF suspension. A spray-dryer was used to develop a wettable baculovirus powder and Response Surface methodology was used to optimize the process. Two carriers, namely Polysaccharide-MS and Polysaccharide-WM were used and inlet temperature, air speed and feed flow rate were used as the model factors. The response factors monitored were powder yield (mg/ml), active ingredient yield of the occlusion bodies (OBs/mg), and moisture content (%). The effect of spray-drying on the microbial load of the samples was also examined. The optimal conditions for Polysaccharide-WM were determined to be an inlet temperature of 130 °C, air speed dial setting of 45 and feed flow rate of 9 ml/minute. According to the predictive models obtained, this would give a powder yield of 337.5 mg, active ingredient yield of 8.0 x 105 OBs/mg and moisture content of 4.8 %. The optimal conditions for Polysaccharide-MS were determined to be an inlet temperature of 130 °C, air speed dial setting of 45 and feed flow rate of 9 ml/minute. According to the predictive models obtained, this would give a powder yield of 110.9 mg/ml, active ingredient yield of 1.0 x 106 OBs/mg and moisture content of 4 %. Spraydrying reduced the microbial load of the sample four-fold. Baculovirus biopesticides in the form of suspensions and wettable powders were developed and evaluated in this project and will form the foundation for the development of commercial biopesticides for the control of the African cotton bollworm

Evolutionary tracks for Betelgeuse

We have constructed a series of non-rotating quasi-hydrostatic evolutionary models for the M2 Iab supergiant Betelgeuse ($\alpha~Orionis$). Our models are constrained by multiple observed values for the temperature, luminosity, surface composition and mass loss for this star, along with the parallax distance and high resolution imagery that determines its radius. We have then applied our best-fit models to analyze the observed variations in surface luminosity and the size of detected surface bright spots as the result of up-flowing convective material from regions of high temperature in the surface convective zone. We also attempt to explain the intermittently observed periodic variability in a simple radial linear adiabatic pulsation model. Based upon the best fit to all observed data, we suggest a best progenitor mass estimate of $20 ^{+5}_{-3} M_\odot$ and a current age from the start of the zero-age main sequence of $8.0 - 8.5$ Myr based upon the observed ejected mass while on the giant branch.Comment: 27 pages, 11 figures, Revised per referee suggestions, Accepted for publication in the Astrophysical Journa

Private Property in America: Land Use and the Ethics of Owning Land

Private property in the United States arose out of a tradition that emphasized the individual freedom to control holdings without interference from governmental influences. A sharp distinction between society as a whole and individual rights isolated ownership of private property from a notion of the common good. This dualistic framework excludes the possibility for forms of property that do not fall completely into either category. Property ownership attitudes are central to issues that often divide environmentalists and landowners. Property rights must be put in the context to understand the divergence between landowner attitudes and provisions made when the institution of private property was created. Finally, land itself as a type of property should be considered ethically distinct from other forms of property because of the interdependencies of human and nonhuman interests that the science of ecology has revealed