Following basal stem rot in young oil palm plantings

The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected

Flexible Ultrathin PolyDVB/EVB Composite Membranes for the Optimization of a Whole Blood Glucose Sensor.

An ultrathin composite membrane has been developed as the outer covering barrier in a model amperometric glucose oxidase enzyme electrode. The membrane was formed by cathodic electropolymerization of divinylbenzene/ethylvinylbenzene at the surface of a gold coated polyester support membrane. Permeability coefficients were determined for O2 and glucose across membranes with a range of polymer thicknesses. Anionic interferents (such as ascorbate), were screened from the working electrode via a charge exclusion mechanism. The enzyme electrode showed an initial 10% signal drift when first exposed to whole human blood over a period of 2 hours, after which responses remained essentially stable. Whole blood patient glucose determinations yielded a correlation coefficient of r2=0.99 compared to standard hospital analyses

Memory & Cognition: What difference does gender make?

Small but significant gender differences, typically favoring women, have previously been observed in experiments measuring human episodic memory performance. In three studies measuring episodic memory, we compared performance levels for men and women. Secondary analysis from a pairedassociate learning task revealed a superior ability for women to learn single function pairs (i.e. words that are represented in only one pair), but performance levels for double function pairs (i.e. pairs that contain words that are also used in one other pair) were similar for men and women. We also reanalyzed data from a recognition experiment that used pictures as stimuli, and discovered an enhanced propensity for women to recollect the test probes in comparison to men, but familiarity based judgments had minimal differences between genders. A prospective study was conducted in order to compare the effect of gender on a delayed free recall task that included basic arithmetic problems as part of the distractor task. Implications for gender differences are discussed with regard to biological factors involving estrogen, and relevant social factors

Abstract Law and Political Reality in the Post-European-Accession British Constitution

Abstract Law and Political Reality in the Post-European-Accession British Constitutio

The African cotton-root nematode, Meloidogyne acronea; its pathogenicity and intra-generic infectivity within Gossypium

Dans une série d'expériences en pots, réalisée en serre, #Meloidogyne acronea confirme ses potentialités d'agent pathogène grave du cotonnier, #Gossypium hirsutum cv. Makoka. Les symptômes observés sur les plantes infestées consistent en une prolifération de racines latérales et une déformation de la racine principale conduisant à un rabougrissement de la plante, à un retard de la floraison et à une diminution significative du poids frais des capsules. Ces symptômes sont aggravés lorsque le cotonnier est soumis à un déficit hydrique. Des symptômes racinaires identiques sont observés sur d'autres espèces appartenant au genre #Gossypium, notamment sur l'espèce sauvage #G. herbaceum var. #africanum, considérée comme le précurseur de tous les cotonniers, ainsi que sur des dérivés et sur plusieurs variétés de #G; hirsutum principalement africaines, mais aussi sur les cultivars américains résistants à #M. incognita Auburn 623 et Clevewilt. Les juvéniles de #M. acronea ne sont pas affectés par le gossypol, un aldéhyde terpénique responsable de la résistance de certaines variétés de cotonniers à #M. incognita, lequel immobilise irréversiblement les juvéniles de cette dernière espèce. #M. acronea est endémique des zones semi-arides de l'Afrique subéquatoriale et sa présence dans la zone d'origine de #G. herbaceum var. #africanum constitue une présomption de co-évolution entre les deux espèces. (Résumé d'auteur

Evidence of bedform superimposition and flow unsteadiness in unit-bar deposits, South Saskatchewan River, Canada

Unit-bar deposits are ubiquitous components of river-channel deposits and strongly influence their hydrological properties, yet they are not easy to interpret. This paper concerns details of the internal structures of six unit bars from the South Saskatchewan River, Canada, that were investigated using trenches, epoxy resin peels, and 900 MHz ground-penetrating radar (GPR) profiles. The composition of unit bars depends on flow unsteadiness and superimposed bedforms. Flow unsteadiness causes changes in the mean grain size of the sediment in transport, but is expressed primarily as a change in the type and direction of migration of smaller ripple- and dune-scale bedforms superimposed on unit bars. Superimposed bedforms with heights that exceed 25% of the host bedform height reduce their host's slope and generate inclined sets. Host bedforms with smaller superimposed bedforms form angle-of-repose cross strata with a visible pre-sorting pattern. The relationship between the formative host- and superimposed bedforms and such pre-sorted cross strata can be used to interpret numerous aspects of the three-dimensional geometries of the bedforms. Such detailed interpretations rely on: (i) regularly spaced fine-grained drapes deposited during the passage of troughs of superimposed bedforms, (ii) grain-size sorting patterns generated by sorting within the superimposed bedforms before deposition, (iii) grain-size sorting during deposition by grainfall and intermittent grainflows down the bar lee-slope, and (iv) the presence and nature of low-angle reactivation surfaces.The detailed interpretations revealed that the deposits of dam-related floods were significantly smaller than the deposits of individual unit bars in this study. The unsteady flow and sediment transport conditions are reflected by changes in the structural composition of the unit bars. Reactivation surfaces associated with flow unsteadiness, as opposed to those formed by large superimposed bedforms, were characterized by changes in mean grain size, the buildup of sediment at the base of the bar lee slope, and changes in structures formed by superimposed bedforms. Reactivation surfaces generated by large superimposed bedforms indicate that bedform preservation is likely increased in areas of flow deceleration. The trough deposits of exposed unit bars contained bubble sand, planar laminae due to upper-stage plane beds, and low-angle inclined laminae due to antidunes. These structures indicate that unit-bar troughs can act as ephemeral channels. The composition of the investigated unit bars thus emphasizes the interplay between flow unsteadiness and bed morphology in the formation of sedimentary structures in river channels.Sediment surfaces generate visible GPR reflections where the thickness and contrast in electrical properties of the sediment layers are sufficiently large. Most cross-stratified sets were represented only by reflections from the base of the set, and not by high-angle inclined reflections from the cross strata. The local absence of reflections from cross strata is attributed to the lack of contrast in electrical properties of the well-sorted cross strata and their limited thickness relative to the radar wavelength. In contrast to cross strata, reactivation surfaces formed by large superimposed bedforms and flow unsteadiness were commonly associated with distinct inclined reflections