Transformation of crown gall resistant and susceptible Vitis genotypes by Agrobacterium vitis

Transformation of crown gall-susceptible and -resistant Vitis genotypes by Agrobacterium vitis strain CG49 was studied using uidA (GUS) in the p35SGUSINT construct. When greenhouse-grown material propagated through tissue culture was inoculated with CG49(p35SGUSINT) in vitro, the highly crown gall-susceptible V. vinifera Cabernet Sauvignon displayed GUS activity on 53 % of inoculated explants vs. 5 % for the resistant V. amurensis and 0 % for the resistant Couderc 3309. Response of Cabernet Sauvignon suggested a strong effect of shoot polarity on transformation. Inoculation of basal vs. apical explant surface in Cabernet Sauvignon indicated transformation in 88 % of basal inoculated explants with no transformation from apical inoculation. Basal inoculations indicated no transformation of V. amurensis and transformation in 10 % of Couderc 3309 explants. Inoculation of intact plants with CG49(p35SGUSINT) produced GUS-positive sites at 56 % of inoculated sites in Cabernet Sauvignon, 10 % of V. amurensis inoculated sites and 9 % of Couderc 3309 inoculated sites. Resistance to crown gall in these genotypes appears to be due to reduced susceptibility to transformation by A. vitis rather than post-transformation phenomena. These studies were complicated by production of GUS-positive spots from in vitro inoculations using wild-type CG49. Resident microorganisms producing b-glucuronidase may proliferate after tissue degradation by A. vitis-induced cell disruption. Use of in vitro internodal explants from tissue culture-propagated vines greatly reduced GUS expression from control CG49 inoculations and these were readily distinguished (by appearance and location) from GUS-positive spots resulting from transformation with uidA

Endophytic Agrobacterium in crown gall-resistant and -susceptible Vitis genotypes

Several methods were used to study endophytic colonization of Vitis genotypes by Agrobacterium vitis (AV). AV was seldom detected except at inoculated sites, indicating little systemic movement of the bacterium under the conditions of these experiments. AV populations at inoculated sites were evaluated for 10 months following inoculation of crown gall-resistant and -susceptible genotypes. Two months after inoculation, V. amurensis selections had significantly smaller populations than V. vinifera (Cabernet Sauvignon) or V. riparia x V. rupestris (C3309). All crown gall-resistant genotypes had significantly lower populations than Cabernet Sauvignon 10 months after inoculation. Examination of vines one year after inoculation indicated that AV populations were much higher at inoculated sites when crown galls developed. However, even when no galls were apparent, Cabernet Sauvignon had significantly higher AV populations than V. amurensis 689 (6-fold higher) and C3309 (70-fold higher). Crown gall-resistant genotypes appear to support lower populations of AV than the crow gall-susceptible Cabernet Sauvignon. Freezing followed by a two-day incubation significantly increased recovery of Agrobacterium using vascular fluid displacement in naturally-infected and artifically-inoculated vines and therefore increased the sensitivity of indexing for AV in grapevines

Exploring the psychological rewards of a familiar semirural landscape: connecting to local nature through a mindful approach

This study analyses a 53,000 word diary of a year engaging with nature through over 200 trips to a semi-rural landscape. Thematic analysis revealed two themes; the transition from observer to nature connectedness and the ways in which the natural environment was experienced once a connection was made. These themes are discussed in relation to theories that seek to explain the positive effect of nature and nature connectedness. The findings are important as they suggest that repeated engagement with local semi-rural countryside can lead to a mindful approach and psychological rewards that do not require travel into the wilderness. The work informs further research into outcomes and processes of nature based interventions such as: trip frequency, duration and diary keeping

Methodological approaches to determining the marine radiocarbon reservoir effect

The marine radiocarbon reservoir effect is an offset in 14C age between contemporaneous organisms from the terrestrial environment and organisms that derive their carbon from the marine environment. Quantification of this effect is of crucial importance for correct calibration of the <sup>14</sup>C ages of marine-influenced samples to the calendrical timescale. This is fundamental to the construction of archaeological and palaeoenvironmental chronologies when such samples are employed in <sup>14</sup>C analysis. Quantitative measurements of temporal variations in regional marine reservoir ages also have the potential to be used as a measure of process changes within Earth surface systems, due to their link with climatic and oceanic changes. The various approaches to quantification of the marine radiocarbon reservoir effect are assessed, focusing particularly on the North Atlantic Ocean. Currently, the global average marine reservoir age of surface waters, R(t), is c. 400 radiocarbon years; however, regional values deviate from this as a function of climate and oceanic circulation systems. These local deviations from R(t) are expressed as +R values. Hence, polar waters exhibit greater reservoir ages (δR = c. +400 to +800 <sup>14</sup>C y) than equatorial waters (δR = c. 0 <sup>14</sup>C y). Observed temporal variations in δR appear to reflect climatic and oceanographic changes. We assess three approaches to quantification of marine reservoir effects using known age samples (from museum collections), tephra isochrones (present onshore/offshore) and paired marine/terrestrial samples (from the same context in, for example, archaeological sites). The strengths and limitations of these approaches are evaluated using examples from the North Atlantic region. It is proposed that, with a suitable protocol, accelerator mass spectrometry (AMS) measurements on paired, short-lived, single entity marine and terrestrial samples from archaeological deposits is the most promising approach to constraining changes over at least the last 5 ky BP

Sedimentology and climatic environment of alluvial fans in the Martian Saheki Crater and a comparison with terrestrial fans in the Atacama Desert

The deflated surfaces of the alluvial fans in Saheki crater reveal the most detailed record of fan stratigraphy and evolution found, to date, on Mars. During deposition of at least the uppermost 100 m of fan deposits, discharges from the source basin consisted of channelized flows transporting sediment (which we infer to be primarily sand- and gravel-sized) as bedload coupled with extensive overbank mud-rich flows depositing planar beds of sand-sized or finer sediment. Flow events are inferred to have been of modest magnitude (probably less than ~60 m3/s), of short duration, and probably occupied only a few distributaries during any individual flow event. Occasional channel avulsions resulted in the distribution of sediment across the entire fan. A comparison with fine-grained alluvial fans in Chile’s Atacama Desert provides insights into the processes responsible for constructing the Saheki crater fans: sediment is deposited by channelized flows (transporting sand through boulder-sized material) and overbank mudflows (sand size and finer) and wind erosion leaves channels expressed in inverted topographic relief. The most likely source of water was snowmelt released after annual or epochal accumulation of snow in the headwater source basin on the interior crater rim during the Hesperian to Amazonian periods. We infer the Saheki fans to have been constructed by many hundreds of separate flow events, and accumulation of the necessary snow and release of meltwater may have required favorable orbital configurations or transient global warming

Lines, Circles, Planes and Spheres

Let $S$ be a set of $n$ points in $\mathbb{R}^3$, no three collinear and not all coplanar. If at most $n-k$ are coplanar and $n$ is sufficiently large, the total number of planes determined is at least $1 + k \binom{n-k}{2}-\binom{k}{2}(\frac{n-k}{2})$. For similar conditions and sufficiently large $n$, (inspired by the work of P. D. T. A. Elliott in \cite{Ell67}) we also show that the number of spheres determined by $n$ points is at least $1+\binom{n-1}{3}-t_3^{orchard}(n-1)$, and this bound is best possible under its hypothesis. (By $t_3^{orchard}(n)$, we are denoting the maximum number of three-point lines attainable by a configuration of $n$ points, no four collinear, in the plane, i.e., the classic Orchard Problem.) New lower bounds are also given for both lines and circles.Comment: 37 page

Ambient particulate pollution and the world-wide prevalence of asthma, rhinoconjunctivitis and eczema in children: Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC)

Objectives: To investigate the effect of ambient particulate matter on variation in childhood prevalence of asthma, rhinoconjunctivitis and eczema. Methods: Prevalences of asthma, rhinoconjunctivitis and eczema obtained in Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) were matched with city-level estimates of residential PM10 obtained from a World Bank model. Associations were investigated using binomial regression adjusting for GNP per capita and for clustering within country. For countries with more than one centre, a two stage meta-analysis was carried out. The results were compared with a meta-analysis of published multi-centre studies. Results: Annual concentrations of PM₁₀ at city level were obtained for 105 ISAAC centres in 51 countries. After controlling for GNP per capita, there was a weak negative association between PM₁₀ and various outcomes. For severe wheeze in 13-14-year-olds, the OR for a 10 μg/m³ increase in PM₁₀ was 0.92 (95 CI 0.84 to 1.00). In 24 countries with more than one centre, most summary estimates for within-country associations were weakly positive. For severe wheeze in 13-14-year-olds, the summary OR for a 10 μg/m³ increase in PM₁₀ was 1.01 (0.92 to 1.10). This result was close to a summary OR of 0.99 (0.91 to 1.06) obtained from published multi-centre studies. Conclusions: Modelled estimates of particulate matter at city level are imprecise and incomplete estimates of personal exposure to ambient air pollutants. Nevertheless, our results together with those of previous multi-centre studies, suggest that urban background PM₁₀ has little or no association with the prevalence of childhood asthma, rhinoconjunctivitis or eczema either within or between countries