Spark Plug Defects and Tests

The successful operation of the spark plug depends to a large extent on the gas tightness of the plug. Part 1 of this report describes the method used for measuring the gas tightness of aviation spark plugs. Part 2 describes the methods used in testing the electrical conductivity of the insulation material when hot. Part 3 describes the testing of the cold dielectric strength of the insulation material, the resistance to mechanical shock, and the final engine test

HIV selfscreening distribution preferences and experiences among men who have sex with men in Mpumalanga Province: Informing policy for South Africa

Current research suggests that HIV self-screening (HIVSS) is a feasible and acceptable approach to increase HIV testing among men who have sex with men (MSM). However, few data are available to shape policy around dissemination and implementation. Gaps in knowledge include preferences for distribution of HIVSS kits, potential social harms and benefits of their use, and how much test users would be willing to pay for the kits. The aim was to inform policy recommendations to optimise distribution of HIVSS kits to MSM in South Africa (SA), where there is a high HIV incidence and unmet testing needs. MSM in the high-HIV-prevalence Gert Sibande and Ehlanzeni districts of Mpumalanga Province, SA, were enrolled between October 2015 and May 2017. Participants were provided with their choice of blood or oral fluid HIVSS test kits, receiving 5 kits at enrolment and 4 additional kits at the 3-month follow-up visit. Questionnaires were administered at enrolment, 3 months and 6 months. We analysed participants’ reported social benefits and harms, and their preferences for kit distribution and pricing. Among 127 MSM screened and enrolled, 114 responded to follow-up questionnaires regarding distribution preferences, 49.3% preferred to acquire HIVSS kits at a community-based organisation (CBO) and 42.7% at a clinic, with 8% preferring a pharmacy. Participants with higher education preferred CBO sites for distribution; in other respects preferences were similar by demographic characteristics. Reported social benefits were common, including knowing one’s status, prevention knowledge gained and improved communication with partners. Despite ubiquitous interest in using the kits, the majority of MSM could not afford to purchase test kits. SA guidelines have integrated HIVSS into HIV and testing policy, but little has been published regarding distribution channels of the kits for MSM and other key populations. There is a partnership between the National Department of Health and CBOs that specialise in key population programming to ensure MSM and other populations with unmet testing needs can access affordable test kits. We observed no social harms, and there were multiple social benefits. Consequently, we recommend immediate free or low-cost distribution of HIVSS kits to MSM through community-based initiatives. Future research should continue to assess optimised linkage to care

From planning the port/city to planning the port-city : exploring the economic interface in European port cities

In last three decades, planning agencies of most ports have institutionally evolved into a (semi-) independent port authority. The rationale behind this process is that port authorities are able to react more quickly to changing logistical and spatial preferences of maritime firms, hence increasing the competitiveness of ports. Although these dedicated port authorities have proven to be largely successful, new economic, social, and environmental challenges are quickly catching up on these port governance models, and particularly leads to (spatial) policy ‘conflicts’ between port and city. This chapter starts by assessing this conflict and argue that the conflict is partly a result of dominant—often also academic—spatial representations of the port city as two separate entities. To escape this divisive conception of contemporary port cities, this chapter presents a relational visualisation method that is able to analyse the economic interface between port and city. Based on our results, we reflect back on our proposition and argue that the core challenge today for researchers and policy makers is acknowledging the bias of port/city, being arguably a self-fulfilling prophecy. Hence, we turn the idea of (planning the) port/city conflicts into planning the port-city’s strengths and weaknesses

The European Union, borders and conflict transformation: the case of Cyprus

Much of the existing literature on the European Union (EU), conflict transformation and border dynamics has been premised on the assumption that the nature of the border determines EU intervention and the consequences that flow from this in terms of EU impact. The article aims to transcend this literature through assessing how domestic interpretations influence EU border transformation in conflict situations, taking Cyprus as a case study. Moreover, the objective is to fuse the literature on EU bordering impact and perceptions of the EU’s normative projection in conflict resolution. Pursuing this line of inquiry is an attempt to depart from the notion of borders being constructed solely by unidirectional EU logics of engagement or bordering practices to a conceptualization of the border as co-constituted space, where the interpretations of the EU’s normative projections by conflict parties, and the strategies that they pursue, can determine the relative openness of the EU border

Atomic-scale modeling of the deformation of nanocrystalline metals

Nanocrystalline metals, i.e. metals with grain sizes from 5 to 50 nm, display technologically interesting properties, such as dramatically increased hardness, increasing with decreasing grain size. Due to the small grain size, direct atomic-scale simulations of plastic deformation of these materials are possible, as such a polycrystalline system can be modeled with the computational resources available today. We present molecular dynamics simulations of nanocrystalline copper with grain sizes up to 13 nm. Two different deformation mechanisms are active, one is deformation through the motion of dislocations, the other is sliding in the grain boundaries. At the grain sizes studied here the latter dominates, leading to a softening as the grain size is reduced. This implies that there is an ``optimal'' grain size, where the hardness is maximal. Since the grain boundaries participate actively in the deformation, it is interesting to study the effects of introducing impurity atoms in the grain boundaries. We study how silver atoms in the grain boundaries influence the mechanical properties of nanocrystalline copper.Comment: 10 pages, LaTeX2e, PS figures and sty files included. To appear in Mater. Res. Soc. Symp. Proc. vol 538 (invited paper). For related papers, see http://www.fysik.dtu.dk/~schiotz/publist.htm

HIV self-screening distribution preferences and experiences among men who have sex with men in Mpumalanga Province: Informing policy for South Africa

Current research suggests that HIV self-screening (HIVSS) is a feasible and acceptable approach to increase HIV testing among men who have sex with men (MSM). However, few data are available to shape policy around dissemination and implementation. Gaps in knowledge include preferences for distribution of HIVSS kits, potential social harms and benefits of their use, and how much test users would be willing to pay for the kits. The aim was to inform policy recommendations to optimise distribution of HIVSS kits to MSM in South Africa (SA), where there is a high HIV incidence and unmet testing needs. MSM in the high-HIV-prevalence Gert Sibande and Ehlanzeni districts of Mpumalanga Province, SA, were enrolled between October 2015 and May 2017. Participants were provided with their choice of blood or oral fluid HIVSS test kits, receiving 5 kits at enrolment and 4 additional kits at the 3-month follow-up visit. Questionnaires were administered at enrolment, 3 months and 6 months. We analysed participants’ reported social benefits and harms, and their preferences for kit distribution and pricing. Among 127 MSM screened and enrolled, 114 responded to follow-up questionnaires regarding distribution preferences, 49.3% preferred to acquire HIVSS kits at a community-based organisation (CBO) and 42.7% at a clinic, with 8% preferring a pharmacy. Participants with higher education preferred CBO sites for distribution; in other respects preferences were similar by demographic characteristics. Reported social benefits were common, including knowing one’s status, prevention knowledge gained and improved communication with partners. Despite ubiquitous interest in using the kits, the majority of MSM could not afford to purchase test kits. SA guidelines have integrated HIVSS into HIV and testing policy, but little has been published regarding distribution channels of the kits for MSM and other key populations. There is a partnership between the National Department of Health and CBOs that specialise in key population programming to ensure MSM and other populations with unmet testing needs can access affordable test kits. We observed no social harms, and there were multiple social benefits. Consequently, we recommend immediate free or low-cost distribution of HIVSS kits to MSM through community-based initiatives. Future research should continue to assess optimised linkage to care

Cellular and humoral immune responses and protection against schistosomes induced by a radiation-attenuated vaccine in chimpanzees

The radiation-attenuated Schistosoma mansoni vaccine is highly effective in rodents and primates but has never been tested in humans, primarily for safety reasons. To strengthen its status as a paradigm for a human recombinant antigen vaccine, we have undertaken a small-scale vaccination and challenge experiment in chimpanzees (Pan troglodytes). Immunological, clinical, and parasitological parameters were measured in three animals after multiple vaccinations, together with three controls, during the acute and chronic stages of challenge infection up to chemotherapeutic cure. Vaccination induced a strong in vitro proliferative response and early gamma interferon production, but type 2 cytokines were dominant by the time of challenge. The controls showed little response to challenge infection before the acute stage of the disease, initiated by egg deposition. In contrast, the responses of vaccinated animals were muted throughout the challenge period. Vaccination also induced parasite-specific immunoglobulin M (IgM) and IgG, which reached high levels at the time of challenge, while in control animals levels did not rise markedly before egg deposition. The protective effects of vaccination were manifested as an amelioration of acute disease and overall morbidity, revealed by differences in gamma-glutamyl transferase level, leukocytosis, eosinophilia, and hematocrit. Moreover, vaccinated chimpanzees had a 46% lower level of circulating cathodic antigen and a 38% reduction in fecal egg output, compared to controls, during the chronic phase of infection

Evaluation of Phage Display Discovered Peptides as Ligands for Prostate-Specific Membrane Antigen (PSMA)

The aim of this study was to identify potential ligands of PSMA suitable for further development as novel PSMA-targeted peptides using phage display technology. The human PSMA protein was immobilized as a target followed by incubation with a 15-mer phage display random peptide library. After one round of prescreening and two rounds of screening, high-stringency screening at the third round of panning was performed to identify the highest affinity binders. Phages which had a specific binding activity to PSMA in human prostate cancer cells were isolated and the DNA corresponding to the 15-mers were sequenced to provide three consensus sequences: GDHSPFT, SHFSVGS and EVPRLSLLAVFL as well as other sequences that did not display consensus. Two of the peptide sequences deduced from DNA sequencing of binding phages, SHSFSVGSGDHSPFT and GRFLTGGTGRLLRIS were labeled with 5-carboxyfluorescein and shown to bind and co-internalize with PSMA on human prostate cancer cells by fluorescence microscopy. The high stringency requirements yielded peptides with affinities KD∼1 μM or greater which are suitable starting points for affinity maturation. While these values were less than anticipated, the high stringency did yield peptide sequences that apparently bound to different surfaces on PSMA. These peptide sequences could be the basis for further development of peptides for prostate cancer tumor imaging and therapy. © 2013 Shen et al

Top quark physics in hadron collisions

The top quark is the heaviest elementary particle observed to date. Its large mass makes the top quark an ideal laboratory to test predictions of perturbation theory concerning heavy quark production at hadron colliders. The top quark is also a powerful probe for new phenomena beyond the Standard Model of particle physics. In addition, the top quark mass is a crucial parameter for scrutinizing the Standard Model in electroweak precision tests and for predicting the mass of the yet unobserved Higgs boson. Ten years after the discovery of the top quark at the Fermilab Tevatron top quark physics has entered an era where detailed measurements of top quark properties are undertaken. In this review article an introduction to the phenomenology of top quark production in hadron collisions is given, the lessons learned in Tevatron Run I are summarized, and first Run II results are discussed. A brief outlook to the possibilities of top quark research a the Large Hadron Collider, currently under construction at CERN, is included.Comment: 84 pages, 32 figures, accepted for publication by Reports on Progress in Physic

The impact of predation by marine mammals on Patagonian toothfish longline fisheries

Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited and focused in areas of putative migration routes, and the impact is compounded as a result of the fishery also concentrating in those areas at those times. Understanding the seasonal behaviour of orcas and the spatial and temporal distribution of “depredation hot spots” can reduce marine mammal interactions, will improve assessment and management of the stock and contribute to increased operational efficiency of the fishery. Such information is valuable in the effort to resolve the human-mammal conflict for resources