Investigation into the Aroma of Rosemary using Multi-Channel Silicone Rubber Traps, Off-line Olfactometry and Comprehensive Two-dimensional Gas Chromatography-Mass Spectrometry

Multi-channel polydimethylsiloxane rubber traps were used to sample the headspace of rosemary samples (two essential oils from different sources, one oleoresin and one dried herb) followed by comprehensive two-dimensional gas chromatography – time of flight mass spectrometry(GCxGC-TOFMS)orGC-MSanalyses. The aromaof different headspace samples was characterized using a custom-built olfactory apparatus. The differences between the aroma profiles were evident from bubble plots of the perceived aroma at different temperatures. The samples were heat-treated to simulate cooking of food products, and were then reassessed to determine any changes in the aroma profile. It was found that the intense menthol and cooling aromas subsided in all the samples with heating. GCxGC-TOFMS allowed for separation of the numerous components in the headspace samples. Manyterpenes and aliphatics were thus tentatively identified and the relative peak areas were compared to better understand the mixture that contributes to the rosemary aroma.KEYWORDS Rosemary, multi-channel silicone rubber traps, GCxGC-TOFMS, essential oil, off-line olfactometry

System dynamics as a tool for exploring greenhouse gas emission mitigation potential in freight transport

In this study, system dynamics modelling is used to evaluate the impacts of decisions made by different decision makers in the freight subsector on the performance of the sector, as measured in terms of greenhouse gas (GHG) emissions, direct job creation, water usage and various externality costs. The focus is on gaining a deeper understanding of opportunities for reducing GHGs, and particularly on the shift of freight from road to rail. Transport of processed food along the Cape Town-Gauteng corridor is used as a case study. Decision makers considered include the freight owners and those responsible for decisions around the vehicle fleet. In the model, decision makers respond to a number of aspects of system performance, including cost, system reliability and taxes. These aspects inform their decision to shift freight on or off rail, or to invest in efficiency interventions. Decisions made in one year impact on overall system performance, which may change a decision maker?s actions in the following year. This paper describes in detail the structure of the model and how it functions. It also discusses the necessary input data, and how this was gathered. Finally, simulation results are presented and discussed.Paper presented at the 34th Annual Southern African Transport Conference 6-9 July 2015 "Working Together to Deliver - Sakha Sonke", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US

Understanding the barriers to a shift of processed food from road to rail through system dynamics

One of the most important greenhouse gas (GHG) mitigation opportunities identified for the freight transport sector is a mode shift from road to rail. A system dynamics model was constructed to evaluate the drivers and barriers to such a mode shift and the impact on the wider economy. This paper focuses on the decision-making process that determines the movement of corridor freight, using processed food on the Cape Town-Gauteng corridor as a case study. In order that the model was an accurate representation which would facilitate discussion amongst decision makers, stakeholders were consulted as to the most important considerations in transporting processed food, their current perception of rail and the barriers to shifting to rail. Stakeholders included not only the decision makers, which included manufacturers of processed food and major retailers, but also Transnet, logistics companies, bodies lobbying government for a switch from road to rail and other experts. The paper presents the insights gained from stakeholder engagement and describes how it informed the construction of the decision-making routines in the system dynamics model. The relative importance of different decision making criteria and the tipping points in the system have begun to be identified, together with the implications of this for achieving a road to rail shift.Paper presented at the 34th Annual Southern African Transport Conference 6-9 July 2015 "Working Together to Deliver - Sakha Sonke", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US

Competitive tendering and deregulation in the British bus

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Collaboration Towards a More Inclusive Society: The Case of South African ICT4D Researchers

In this study, research collaboration in the context of South African Information and Communication for Development (ICT4D) researchers was investigated using a mixed methods approach. South Africa, a country with stark development challenges and on the other hand a well-established ICT infrastructure, provides an appropriate context for ICT4D research. Firstly, a quantitative analysis of South African research collaboration between 2003 and 2016 was conducted to determine the existing research collaboration patterns of South African ICT4D researchers. This is based on the publications in three top ICT4D journals namely the Electronic Journal of Information Systems in Developing Countries (EJISDC), Information Technologies & International Development (ITID), and Information Technology for Development (ITD). The results show that most co-authored papers were intra-institutional collaborations, with limited inter-institutional collaboration between South African authors or between South African and other African authors. Secondly, interviews were conducted with South African researchers who emerged as inter- and intra-institutional collaborators to gain insight into the technology, drivers and barriers affecting South African research collaboration. We report our findings and discuss the implications for employing research collaboration as a mechanism for addressing inequality and supporting inclusion.School of Computin

Prevalence and Determinants of Vitamin D Deficiency in 1825 Cape Town Primary Schoolchildren: A Cross-Sectional Study

Vitamin D deficiency (25-hydroxyvitamin D[25(OH)D] <50 nmol/L) is common among adults in Cape Town, South Africa, but studies investigating vitamin D status of children in this setting are lacking. We conducted a cross-sectional study to determine the prevalence and determinants of vitamin D deficiency in 1825 Cape Town schoolchildren aged 6–11 years. Prevalence of vitamin D deficiency was 7.6% (95% Confidence Interval [CI] 6.5% to 8.9%). Determinants of vitamin D deficiency included month of sampling (adjusted odds ratio [aOR] for July–September vs. January–March 10.69, 95% CI 5.02 to 22.77; aOR for October–December vs. January–March 6.73, 95% CI 2.82 to 16.08), older age (aOR 1.25 per increasing year, 95% CI: 1.01–1.53) and higher body mass index (BMI; aOR 1.24 per unit increase in BMI-for-age Z-score, 95% CI: 1.03–1.49). In a subset of 370 participants in whom parathyroid hormone (PTH) concentrations were measured; these were inversely related to serum 25(OH)D concentrations (p < 0.001). However, no association between participants with hyperparathyroidism (PTH >6.9 pmol/L) and vitamin D deficiency was seen (p = 0.42). In conclusion, we report that season is the major determinant of vitamin D status among Cape Town primary schoolchildren, with prevalence of vitamin D deficiency ranging from 1.4% in January–March to 22.8% in July–September

Biochemical characterization of Acacia schweinfurthii serine proteinase inhibitor

One of the many control mechanisms of serine proteinases is their specific inhibition by protein proteinase inhibitors. An extract of Acacia schweinfurthii was screened for potential serine proteinase inhibition. It was successfully purified to homogeneity by precipitating with 80% (v/v) acetone and sequential chromatographic steps, including ion-exchange, affinity purifica- Q2 tion and RP-HPLC. Reducing SDS-PAGE conditions revealed an inhibitor (ASTI) consisting of two polypeptide chains A and B of approximate molecular weights of 16 and 10 kDa, respectively, and under non-reducing conditions, 26 kDa was observed. The inhibitor was shown to inhibit bovine trypsin (Ki of 3.45 nM) at an approximate molar ratio of inhibitor: trypsin (1:1). The A- and B-chains revealed complete sequences of 140 and 40 amino acid residues, respectively. Sequence similarity (70%) was reported between ASTI A-chain and ACTI A-chain (Acacia confusa) using the ClustalW. The B-chain produced a 76% sequence similarity between ASTI and Leucaena leucocephala trypsin inhibitor

Genetic inhibition of neurotransmission reveals role of glutamatergic input to dopamine neurons in high-effort behavior

Midbrain dopamine neurons are crucial for many behavioral and cognitive functions. As the major excitatory input, glutamatergic afferents are important for control of the activity and plasticity of dopamine neurons. However, the role of glutamatergic input as a whole onto dopamine neurons remains unclear. Here we developed a mouse line in which glutamatergic inputs onto dopamine neurons are specifically impaired, and utilized this genetic model to directly test the role of glutamatergic inputs in dopamine-related functions. We found that while motor coordination and reward learning were largely unchanged, these animals showed prominent deficits in effort-related behavioral tasks. These results provide genetic evidence that glutamatergic transmission onto dopaminergic neurons underlies incentive motivation, a willingness to exert high levels of effort to obtain reinforcers, and have important implications for understanding the normal function of the midbrain dopamine system.Fil: Hutchison, M. A.. National Institutes of Health; Estados UnidosFil: Gu, X.. National Institutes of Health; Estados UnidosFil: Adrover, Martín Federico. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Lee, M. R.. National Institutes of Health; Estados UnidosFil: Hnasko, T. S.. University of California at San Diego; Estados UnidosFil: Alvarez, V. A.. National Institutes of Health; Estados UnidosFil: Lu, W.. National Institutes of Health; Estados Unido

Measuring the intensity of conflicts in conservation

Conflicts between the interests of biodiversity conservation and other human activities pose a major threat to natural ecosystems and human well‐being, yet few methods exist to quantify their intensity and model their dynamics. We develop a categorization of conflict intensity based on the curve of conflict, a model originally used to track the escalation and deescalation of armed conflicts. Our categorization assigns six intensity levels reflecting the discourse and actions of stakeholders involved in a given conflict, from coexistence or collaboration to physical violence. Using a range of case studies, we demonstrate the value of our approach in quantifying conflict trends, estimating transition probabilities between conflict stages, and modeling conflict intensity as a function of relevant covariates. By taking an evidence‐based approach to quantifying stakeholder behavior, the proposed framework allows for a better understanding of the drivers of conservation conflict development across a diverse range of socioecological scenarios

Outcomes of laboratory-confirmed SARS-CoV-2 infection during resurgence driven by Omicron lineages BA.4 and BA.5 compared with previous waves in the Western Cape Province, South Africa

OBJECTIVE: We aimed to compare clinical severity of Omicron BA.4/BA.5 infection with BA.1 and earlier variant infections among laboratory-confirmed SARS-CoV-2 cases in the Western Cape, South Africa, using timing of infection to infer the lineage/variant causing infection. METHODS: We included public sector patients aged ≥20 years with laboratory-confirmed COVID-19 between 1-21 May 2022 (BA.4/BA.5 wave) and equivalent prior wave periods. We compared the risk between waves of (i) death and (ii) severe hospitalization/death (all within 21 days of diagnosis) using Cox regression adjusted for demographics, comorbidities, admission pressure, vaccination and prior infection. RESULTS: Among 3,793 patients from the BA.4/BA.5 wave and 190,836 patients from previous waves the risk of severe hospitalization/death was similar in the BA.4/BA.5 and BA.1 waves (adjusted hazard ratio (aHR) 1.12; 95% confidence interval (CI) 0.93; 1.34). Both Omicron waves had lower risk of severe outcomes than previous waves. Prior infection (aHR 0.29, 95% CI 0.24; 0.36) and vaccination (aHR 0.17; 95% CI 0.07; 0.40 for at least 3 doses vs. no vaccine) were protective. CONCLUSION: Disease severity was similar amongst diagnosed COVID-19 cases in the BA.4/BA.5 and BA.1 periods in the context of growing immunity against SARS-CoV-2 due to prior infection and vaccination, both of which were strongly protective