Beam to Chart: A Case Study of the LIDAR Survey of the Sound of Harris

Tenix LADS Corporation conducted the LIDAR survey of the Sound of Harris in March 2004, for the Maritime and Coastguard Agency (MCA). The survey was conducted using the LADS Mk II system. The survey area was most complex with many islands, shoals and narrow channels (see Figure 1). Survey data extended from topographic heights up to 50 metres above the sea surface to maximum depths of 25 metres below chart datum.Tenix LADS Corporation llevô a cabo un levantamiento LIDAR del Pasaje de Harris para la Agenda Marîtima y de Guardacostas (AMG), en Marzo del 2004. El levantamiento fue realizado utilizando el sistema LADS Mk II. El ârea del levantamiento era bastante compleja, con muchas islas, bajos fondos y canales angostos (ver Figura 1). Los datos del levantamiento comprendieron desde alturas topogrâficas de hasta 50 metros sobre la superficie del mar, hasta profundidades mâximas de 25 metros por debajo del dâtum de la carta.Tenix LADS Corporation a exécuté un levé LIDAR du passage Harris en mars 2004, pour la MCA (Maritime and Coastguard Agency). Le levé a été effectué à l ’aide du système LADS Mk II. La zone de levé était très complexe, avec de nombreuses îles ainsi que de nombreux hauts fonds et passages étroits (voir Figure 1). Les données des levés vont de hauteurs topographiques atteignant 50 mètres au-dessus de la surface de la mer jusqu’à des profondeurs maximum de 25 mètres au-dessous du niveau de référence des cartes marines

On Differential Rotation and Convection in the Sun

We show that the differential rotation profile of the solar convection zone, apart from inner and outer boundary layers, can be reproduced with great accu- racy if the isorotation contours correspond to characteristics of the thermal wind equation. This requires that there be a formal quantitative relationship involving the entropy and the angular velocity. Earlier work has suggested that this could arise from magnetohydrodynamic stability constraints; here we argue that purely hydrodynamical processes could also lead to such a result. Of special importance to the hydrodynamical solution is the fact that the thermal wind equation is insensitive to radial entropy gradients. This allows a much more general class of solutions to fit the solar isorotation contours, beyond just those in which the entropy itself must be a function of the angular velocity. In particular, for this expanded class, the thermal wind solution of the solar rotation profile remains valid even when large radial entropy gradients are present. A clear and explicit example of this class of solution appears to be present in published numerical simulations of the solar convective zone. Though hydrodynamical in character, the theory is not sensitive to the presence of weak magnetic fields. Thus, the identification of solar isorotation contours with the characteristics of the thermal wind equation appears to be robust, accommodating, but by no means requiring, magnetic field dynamics.Comment: 16 pages, 2 figures. Accepted for publication in MNRA

Aggregation Kinetics and Filament Structure of a Tau Fragment Are Influenced by the Sulfation Pattern of the Cofactor Heparin

A pathological signature of Alzheimer’s disease (AD) is the formation of neurofibrillary tangles comprising filamentous aggregates of the microtubule associated protein tau. Tau self-assembly is accelerated by polyanions including heparin, an analogue of heparan sulfate. Tau filaments colocalize with heparan sulfate proteoglycans (HSPGs) in vivo, and HSPGs may also assist the transcellular propagation of tau aggregates. Here, we investigate the role of the sulfate moieties of heparin in the aggregation of a recombinant tau fragment Δtau187, comprising residues 255–441 of the C-terminal microtubule-binding domain. The effects that the selective removal of the N-, 2-O-, and 6-O-sulfate groups from heparin have on the kinetics of tau aggregation, aggregate morphology, and protein structure and dynamics were examined. Aggregation kinetics monitored by thioflavin T (ThT) fluorescence revealed that aggregation is considerably slower in the presence of 2-O-desulfated heparin than with N- or 6-O-desulfated heparin. Transmission electron microscopy revealed that tau filaments induced by 2-O-desulfated heparin were more slender than filaments formed in the presence of intact heparin or 6-O-desulfated heparin. The 2-O-desulfated heparin-induced filaments had more extensive regions of flexibility than the other filaments, according to circular dichroism and solid-state NMR spectroscopy. These results indicate that the sulfation pattern of heparin regulates tau aggregation, not purely though electrostatic forces but also through conformational perturbations of heparin when the 2-O-sulfate is removed. These findings may have implications for the progression of AD, as the sulfation pattern of GAGs is known to change during the aging process, which is the main risk factor for the disease

Functionalized micro-capillary film for the rapid at-line analysis of IgG aggregates in a cell culture bioreactor.

A micro-capillary film has been developed that offers the potential for an at-line analytical tool for rapid aggregate analysis during biopharmaceutical antibody production. A non-porous walled micro-capillary film (NMCF) with cation exchange functionality was demonstrated to act as a chromatography medium that could be operated with high linear fluid velocities and was highly resistant to blockage by entrained particulates, including cells. The NMCF containing 19 parallel microcapillaries was prepared using a melt extrusion process from poly(ethylene-vinyl alcohol) copolymer (EVOH). The NMCF-EVOH was modified to have cation-exchange functionality (NMCF-EVOH-SP) and shown to differentially bind monomer and aggregated species of IgG antibody directly from a bioreactor. The use of NMCF-EVOH-SP to quantify aggregate concentrations in monoclonal antibody preparations in less than 20 minutes was demonstrated.The authors would like to thank the EPSRC for the provision of a CASE Award. This study was sponsored by MedImmune, the global biologics R&D arm of AstraZeneca.This is the final version of the article. It first appeared from Taylor & Francis via http://dx.doi.org/10.1080/19420862.2015.106536

Effect of BG-Lures on the Male Aedes (Diptera: Culicidae) Sound Trap capture rates

With global expansion of the two main vectors of dengue, Aedes aegypti (Linnaeus, Diptera: Culicidae) and Aedes albopictus (Skuse, Diptera: Culicidae), there is a need to further develop cost-effective and user-friendly surveillance tools to monitor the population dynamics of these species. The abundance of Ae. aegypti and Ae. Albopictus, and associated bycatch captured by Male Aedes Sound Traps (MASTs) and BG-Sentinel (BGS) traps that were unbaited or baited with BG-Lures were compared in Cairns, Australia and Madang, Papua New Guinea. Mean male Ae. aegypti and Ae. albopictus catch rates in MASTs did not significantly differ when deployed with BG-Lures. Similarly, males of both these species were not sampled at statistically different rates in BGS traps with or without BG-Lures. However, MASTs with BG-Lures caught significantly less male Ae. aegypti than BGS traps baited with BG-Lures in Cairns, and MASTs without BG-Lures caught significantly more male Ae. albopictus than BGS traps without BG-Lures in Madang. Additionally, BG-Lures significantly increased female Ae. aegypti catch rates in BGS traps in Cairns. Lastly, bycatch capture rates in BGS traps were not significantly influenced by the addition of the BG-Lures. While this study provides useful information regarding the surveillance of Ae. aegypti and Ae. albopictus in these locations, further development and investigation is required to successfully integrate an olfactory lure into the MAST system

Designing Aedes mosquito traps: the evolution of the male Aedes sound trap by iterative evaluation insects

Effective surveillance of Aedes aegypti (Linnaeus, Diptera: Culicidae) is critical to monitoring the impact of vector control measures when mitigating disease transmission by this species. There are benefits to deploying male-specific traps, particularly when a high level of catch-specificity is desired. Here, the rationale behind the developmental process of an entirely new trap which uses a sound lure to capture male Ae. aegypti, the male Aedes sound trap (MAST), is presented as a target product profile with findings from developmental trials of key trap components and performance. Trial results suggest that the presence of a black base associated with the trap influenced male catches as did variations in size of this base, to a degree. Trap entrance shape didn’t influence catch rates, but entrance size did. No significant differences in catch rates were found when sound lures were set to intermittent or continuous playbacks, at volumes between 63–74 dB or frequencies of 450 Hz compared to 500 Hz. Additionally, adult males aged 3 days post-eclosion, were less responsive to sound lures set to 500 Hz than those 4 or 6 days old. Lastly, almost no males were caught when the MAST directly faced continual winds of 1.5 ms−1, but males were captured at low rates during intermittent winds, or if the trap faced away from the wind. The developmental process to optimising this trap is applicable to the development of alternate mosquito traps beyond Aedes sound traps and provides useful information towards the improved surveillance of these disease vectors

A low-powered and highly selective trap for male Aedes (Diptera: Culicidae) surveillance: the male Aedes sound trap

As Aedes aegypti (Linnaeus, Diptera: Culicidae) expands its global distribution and vectors a range of debilitating arboviruses there is an increased need for enhanced mosquito surveillance. Consequently, we developed a Male Aedes Sound Trap (MAST) that requires minimal power and is highly species-specific. Two different versions of the MAST were developed, one that uses synthetic pyrethroid to kill captured mosquitoes (MAST Spray) and another which has an internal divider to create a killing chamber in which a sticky panel can be placed to capture mosquitoes (MAST Sticky). We compared weekly capture rates of male Ae. aegypti and bycatch from the two MAST versions to those from BG-Sentinel (BGS) traps and Sound-producing BG-Gravid Aedes Traps (SGATs) throughout Cairns, northern Australia. Weekly mean male Ae. aegypti catches did not significantly differ between trap types. However, the rate of positive weekly detections of male Ae. aegypti was lower for the MAST Sticky than the other three trap types. The MASTs sampled significantly fewer mosquitoes other than male Ae. aegypti, than either the BGS trap or the SGAT. Also, the MASTs and SGATs all caught significantly less non-Culicidae bycatch than the BGS traps. Consequently, we have developed a versatile male Ae. aegypti trap which is potentially of great benefit to Ae. aegypti surveillance programs

Circular dichroism spectroscopy identifies the β-adrenoceptor agonist salbutamol as a direct inhibitor of tau filament formation in vitro.

Potential drug treatments for Alzheimer’s disease (AD) may be found by identifying compounds that block the assembly of the microtubule-associated protein tau into neurofibrillar tangles associated with neuron destabilisation and cell death. Here, a small library of structurally diverse compounds was screened in vitro for the ability to inhibit tau aggregation, using high-throughput synchrotron radiation circular dichroism (HT-SRCD) as a novel tool to monitor the structural changes in the protein as it assembles into filaments. The catecholamine epinephrine was found to be the most effective tau aggregation inhibitor of all 88 compounds screened. Subsequently, we tested chemically-similar phenolamine drugs from the β-adrenergic receptor (βAR) agonist class, using conventional circular dichroism spectroscopy, thioflavin T fluorescence and transmission electron microscopy. Two compounds, salbutamol and dobutamine, used widely in the treatment of respiratory and cardiovascular disease, impede the aggregation of tau in vitro. Dobutamine reduces both the rate and yield of tau filament formation over 24 hours, although it has little effect on the structural transition of tau into β-sheet structures over 24 hours. Salbutamol also reduces the yield and rate of filament formation, and additionally inhibits tau’s structural change into β-sheet rich aggregates. Salbutamol has a good safety profile and a half-life that facilitates permeation through the blood brain barrier and could represent an expediated approach to developing AD therapeutics. These results provide the motivation for in vivo evaluation of pre-existing β-adrenergic receptor agonists as a potential therapy for AD through the reduction of tau deposition in AD

Assistants, Guides, Collaborators, Friends: The Concealed Figures of Conflict Research

Recent scholarship has demonstrated an increasing awareness of the need for more grounded, empirical research into the micro-level dynamics of violent contexts. Research in these difficult, dangerous, and potentially violent conflict or post-conflict settings necessitates the formation of new relationships of dependency, and assistants, friends, collaborators, and guides become central figures in the field. However, all too often, these figures are written out of academic accounts and silenced in our analyses. This not only does them a significant disservice, but it also obscures potential biases, complexities, and ethical dilemmas that emerge in the way in which such research is carried out. Drawing upon fieldwork exploring the 2007–2008 Kenyan postelection violence, this paper argues that reliance upon insider-assistants is essential in conflict settings and explores the challenges inherent in these relationships. As researchers become increasingly engaged in micro-level studies of violent contexts, we must interrogate the realities of how our knowledge has been produced and engage in more open and honest discussions of the methodological and ethical challenges of conflict research

The qualification of collective absolutes and the individuality of persons and events in mid-nineteenth-century Spain

This article argues, on the basis of intellectual, literary, and art history, against the view that mid-nineteenth-century notions of individuality in Spain were products of a social structure based around a bourgeoisie, or, in other accounts, based around a failed effort to establish a bourgeoisie. Instead, it argues that an emphasis on individuality could take radically different forms, that there was no core shared idea of 'individuality'. The article argues that the key motivating factor in these varying notions of individuality was a conflict between and concerning different factions within an oligarchic elite over the future of that elite