The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma-ray spectrometry data

Airborne Gamma Spectrometry (AGS) is well suited to the mapping of radioactivity in the environment. Flight parameters (e.g. speed and line spacing) directly affect the rate of area coverage, cost, and data quality of any survey. The influences of line spacing have been investigated for data from inter‐tidal, coastal and upland environments with a range of <sup>137</sup>Cs activity concentrations and depositional histories. Estimates of the integrated <sup>137</sup>Cs activity (‘inventory’) within specified areas and the shapes of depositional features were calculated for subsets of the data at different line spacings. Features with dimensions greater than the line spacing show variations in inventory and area of less than 3%, and features with dimensions less than the line spacing show larger variations and a decreased probability of detection. The choice of line spacing for a task is dependent on the dimensions of the features of interest and required edge definition. Options for line spacing for different tasks are suggested. It is noted that for regional mapping, even 5–10 km line spacing can produce useful data

A Geographical Location Model for Targeted Implementation of Lure-and-Kill Strategies Against Disease-Transmitting Mosquitoes in Rural Areas

Outdoor devices for luring and killing disease-transmitting mosquitoes have been proposed as potential com- plementary interventions alongside existing intra-domiciliary methods namely insecticide treated nets and house spraying with residual insecticides. To enhance effectiveness of such outdoor interventions, it is essential to optimally locate them in such a way that they target most of the outdoor mosquitoes. Using odour-baited lure and kill stations (OBS) as an example, we describe a map model derived from: 1) com-munity participatory mapping conducted to identify mosquito breeding habitats, 2) entomological field studies conducted to estimate outdoor mosquito densities and to determine safe distances of the OBS from human dwellings, and 3) field surveys conducted to map households, roads, outdoor human aggregations and landmarks. The resulting data were combined in a Ge- ographical Information Systems (GIS) environment and analysed to determine optimal locations for the OBS. Separately, a GIS-interpolated map produced by asking community members to rank different zones of the study area and show where they expected to find most mosquitoes, was visually compared to another map interpolated from the entomological survey of outdoor mosquito densities. An easy-to-interpret suitability map showing optimal sites for placing OBS was produced, which clearly depicted areas least suitable and areas most suitable for locating the devices. Comparative visual interpretation of maps derived from interpolating the community knowledge and entomological data revealed major similarities between the two maps. Using distribution patterns of human and mosquito populations as well as characteristics of candidate outdoor interventions, it is possible to readily determine suitable areas for targeted positioning of the interventions, thus improve effectiveness. This study also highlights possibilities of relying on community knowledge to approximate areas where mosquitoes are most abundant and where to locate outdoor complementary interventions such as odour-baited lure and kill stations for controlling disease-transmitting mosquitoes.\u

Algorithmic approach to adiabatic quantum optimization

It is believed that the presence of anticrossings with exponentially small gaps between the lowest two energy levels of the system Hamiltonian, can render adiabatic quantum optimization inefficient. Here, we present a simple adiabatic quantum algorithm designed to eliminate exponentially small gaps caused by anticrossings between eigenstates that correspond with the local and global minima of the problem Hamiltonian. In each iteration of the algorithm, information is gathered about the local minima that are reached after passing the anticrossing non-adiabatically. This information is then used to penalize pathways to the corresponding local minima, by adjusting the initial Hamiltonian. This is repeated for multiple clusters of local minima as needed. We generate 64-qubit random instances of the maximum independent set problem, skewed to be extremely hard, with between 10^5 and 10^6 highly-degenerate local minima. Using quantum Monte Carlo simulations, it is found that the algorithm can trivially solve all the instances in ~10 iterations.Comment: 7 pages, 3 figure

New hurdles for translational research

New guidelines for the collection and use of human tissues for research will impose new requirements on researchers to seek ethical approval and patient consent. This extends to the use of surplus tissue, such as breast cancer excision biopsies, which, until recently, have been regarded as having been 'abandoned' by the patient. This article argues that some of these new constraints provide hurdles to translational research that are unnecessary for patient protection. This is particularly significant when emerging technologies are expected to elicit major advances in clinical cancer research

Outdoor Mosquito Control Using Odour-Baited Devices: Development and Evaluation of a Potential New Strategy to Complement Indoor Malaria Prevention Methods

A considerable effort is currently underway to develop a malaria vaccine based on live Plasmodium falciparum sporozoites. The first requisite of a sporozoite vaccine is the guarantee of parasite arrest prior to the onset of the pathogenic blood stage. Immunisation with genetically attenuated parasites (GAP) that arrest in the liver forms a promising approach. Work in this thesis describes the development and characterisation of a P. berghei Δb9Δslarp GAP that fully arrests in the liver. Immunisation of multiple mouse strains with low numbers of Δb9Δslarp GAP resulted in sterile protection. The Δb9Δslarp GAP is there- fore the leading GAP vaccine candidate. Work in this the- sis further describes the effect of varying the parameters of sporozoite inoculation on parasite liver load. These findings provide a rationale for the design of clinical trials aimed at the administration of live attenuated P. falciparum sporozoites

A new species of stalked crinoid (Echinodermata) of possible Late Silurian age from central Newfoundland

A new fossil locality within a sequence previously assigned to the Middle Ordovician Baie D'Espoir Group in south-central Newfoundland contains fragmented crinoid columnals and brachiopods. Distinctive, pentastellate crinoid columnals, similar to those assigned to the monobathrid camerate Hexacrinites Austin and Austin by Russian authors, are named Hexacrinites? Pentastellatus n. sp. Nodal(?) columnals of this species have a circular, depressed articular facet, with a conical to bowl-like crenularium, a depressed, circular areola, a raised perilumen and a short, slender axial canal of pentagonal section. The oldest Hexacrinites sensu stricto are Late Silurian, suggesting that the fossiliferous strata have been incorrectly assigned to the Ordovician. Cross-sections of brachiopods from the same locality include an example that resembles several Early Silurian to Late Devonian pentameroid genera including Brooksina Kirk, 1922. Correlation with Late Silurian, bivalve-bearing strata SO km to the northeast would indicate that a major unconformity may occur above the fossiliferous Early and Middle Ordovician strata and the Early Ordovician ophiolite complexes. RÉSUMÉ Un nouvel emplacement de fossiles à I'intérieur d'une sequence auparavant attribute au groupe de l'Ordovicien moyen de Baie d'Espoir dans le centre-sud de Terre-Neuve renferme des fragments de columnales et de brachiopodes de crinoldes. Des columnales de crinoldes pentaétoilées caractéristiqucs, semblables à celles attributées à l’Hexacrinites Austin and Austin à loges monobathrides par des auteurs russes, sont baptisées nouvelle espèce pentastellatus d'Hexacrinites?. Les columnales nodales(?) de cette espèce sont pourvues d'une facette articulaire renfoncée et circulaire munie d'un crenularium allant de conique à bombé, d'une aréole circulaire renfoncie, d'un périlumen surélevé et d'un canal axial mince et court de section pentagonalc. Les plus anciens Hexacrinites, au sens strict, remontent au Silurien supérieur, ce qui permet de supposer qu'on a incorrectement attribué la strate fossilifère à l'Ordovicien. Des iéchantillons représentatifs de brachiopodes du même emplacement comprennent un exemple qui ressemble à plusieurs genres de pentaméroides datant du Silurien inférieur au Dévonien supérieur, notamment le Brooksina Kirk, 1922. Leur corrélation avec des strates renfermant des bivalves du Silurien supérieur à 50 km au nord-cst signale qu'une discordance importantc pourrait se présenter au-dessus des strates fossiliferes de l'Ordovicien inférieur ou moyen de même que des complexes d'ophiolites de l'Ordovicien inférieur. [Traduit par la rédaction

Leading-edge vortices elevate lift of autorotating plant seeds

As they descend, the autorotating seeds of maples and some other trees generate unexpectedly high lift, but how they attain this elevated performance is unknown. To elucidate the mechanisms responsible, we measured the three-dimensional flow around dynamically scaled models of maple and hornbeam seeds. Our results indicate that these seeds attain high lift by generating a stable leading-edge vortex (LEV) as they descend. The compact LEV, which we verified on real specimens, allows maple seeds to remain in the air more effectively than do a variety of nonautorotating seeds. LEVs also explain the high lift generated by hovering insects, bats, and possibly birds, suggesting that the use of LEVs represents a convergent aerodynamic solution in the evolution of flight performance in both animals and plants

Differential Hox expression in murine embryonic stem cell models of normal and malignant hematopoiesis

The Hox family are master transcriptional regulators of developmental processes, including hematopoiesis. The Hox regulators, caudal homeobox factors (Cdx1-4), and Meis1, along with several individual Hox proteins, are implicated in stem cell expansion during embryonic development, with gene dosage playing a significant role in the overall function of the integrated Hox network. To investigate the role of this network in normal and aberrant, early hematopoiesis, we employed an in vitro embryonic stem cell differentiation system, which recapitulates mouse developmental hematopoiesis. Expression profiles of Hox, Pbx1, and Meis1 genes were quantified at distinct stages during the hematopoietic differentiation process and compared with the effects of expressing the leukemic oncogene Tel/PDGFR;2. During normal differentiation the Hoxa cluster, Pbx1 and Meis1 predominated, with a marked reduction in the majority of Hox genes (27/39) and Meis1 occurring during hematopoietic commitment. Only the posterior Hoxa cluster genes (a9, a10, a11, and a13) maintained or increased expression at the hematopoietic colony stage. Cdx4, Meis1, and a subset of Hox genes, including a7 and a9, were differentially expressed after short-term oncogenic (Tel/PDGFR;2) induction. Whereas Hoxa4-10, b1, b2, b4, and b9 were upregulated during oncogenic driven myelomonocytic differentiation. Heterodimers between Hoxa7/Hoxa9, Meis1, and Pbx have previously been implicated in regulating target genes involved in hematopoietic stem cell (HSC) expansion and leukemic progression. These results provide direct evidence that transcriptional flux through the Hox network occurs at very early stages during hematopoietic differentiation and validates embryonic stem cell models for gaining insights into the genetic regulation of normal and malignant hematopoiesis

Interviewing suspects: examining the association between skills, questioning, evidence disclosure, and interview outcomes

The interviewing of suspects is an important element in the investigation of crime. However, studies concerning actual performance of investigators when undertaking such interviews remain sparse. Nevertheless, in England and Wales, since the introduction of a prescribed framework over 20 years ago, field studies have generally shown an improvement in interviewing performance, notwithstanding ongoing concerns largely relating to the more demanding aspects (such as building/maintaining rapport, intermittent summarising and the logical development of topics). Using a sample of 70 real-life interviews, the present study examined questioning and various evidence disclosure strategies (which have also been found demanding), examining their relationships between interview skills and interview outcomes. It was found that when evidence was disclosed gradually (but revealed later), interviews were generally both more skilled and involved the gaining of comprehensive accounts, whereas when evidence was disclosed either early or very late, interviews were found to be both less skilled and less likely to involve this outcome. These findings contribute towards an increased research base for the prescribed framework

Application of the ALAP concept to occupational exposure at operating light water reactors

The application of the as-low-as-practicable (ALAP) concept to radiation exposure of workers at light-water reactors (LWR's) has recently received increased attention. The purpose of the project described is to investigate the means by which occupational exposure at operating LWR's can be reduced to the lowest practicable levels. Nine LWR stations, including 16 operating reactors, were studied in Phase I of the project to identify significant sources of exposure and to determine the magnitude of the exposures. A complete site review consists of compiling information from safety analysis reports, plant technical specifications, and radiation exposure records coupled with an on-site visit for discussions with plant personnel, observation of procedures, and measurement of radiation levels. In Phase II, specific problem areas are being studied in-depth with regard to corrective measures to reduce exposure. Information has been collected on exposure from valve maintenance and repair. Corrective measures will be evaluated with respect to ease of application and cost effectiveness. The results presented will serve as technical backup for the preparation of regulatory guides. (auth