Does value-based prioritization at working memory enhance long-term memory?

Research has demonstrated that individuals can direct their attention to valuable information in both working memory and long-term memory tasks with observable effects on performance. However, it is currently unclear whether prioritising an item for a working memory task automatically translates into a boost at long-term memory. This was examined in two experiments using relatively short (250 ms per item; Experiment 1) and longer (500 ms per item; Experiment 2) encoding times. Participants first completed a visual working memory task, in which they were presented with series of photographs of everyday objects. Following a brief delay (1,000 ms), they completed a four-alternative forced-choice test. Prior to encoding, participants were informed of the point values associated with each item. In some trials, the first item in the sequence was worth more points than the rest. In other trials, all items were equally valuable. After a filled delay, participants completed a surprise long-term memory task. At working memory, a value effect was reliably observed on recognition accuracy, along with some evidence of faster response times for high-value items. However, there was little consistent evidence of this effect automatically persisting into long-term memory. Thus, the benefits of attentional prioritization in working memory do not always translate into longer-term performance. More broadly, this provides further evidence that manipulations that enhance working memory performance do not necessarily enhance long-term memory.

The sensitivity of the Kleihauer-Betke test for placental abruption.

The Kleihauer-Betke (KB) test evaluates fetal blood in the maternal circulation, and is often used when placental abruption is suspected. At our centre, it is the protocol to perform a KB test in all suspected cases of abruption. We carried out a retrospective study of all cases of abruption that occurred at our centre over 6 years. Of the 68 confirmed cases of placental abruption, only three had positive KB tests, giving a sensitivity of only 4.4%. Thus, in the overwhelming majority of cases of confirmed abruption, the KB test was negative. Our findings indicate that the KB test has poor sensitivity for placental abruption and should not be used in the detection of abruption.

Combined physico-chemical and biological sensing in environmental monitoring.

Single-use conductivity and microbial sensors were used to investigate the effect of both species (chloride, nitrate, and sulphate) and concentration/osmolarity of anions on the metabolic activity of Escherichia coli. A new disposable, single-use conductivity sensor is described which is compatible with the CellSense mediated amperometric biosensor system. The effect of changing salinity and nitrate concentration on the response of E. coli to 3,5-dichlorophenol and mercuric chloride was determined. The implications for toxicity assessment of a hybrid sensing system, allowing the simultaneous monitoring of physico-chemical and biological data, are discussed.

Studies on the biosynthesis and metabolism of the phytoalexin lubimin and related compounds in Datura stramonium L.

Arachidonic acid, cellulase, CuSO4, a sonicate of Phytophthora infestans mycelium and a spore suspension of Penicillium chrysogenum all elicited the formation of the sesquiterpenoid phytoalexins lubimin, 3-hydroxylubimin and rishitin in fruit cavities of Datura stramonium. 3-Hydroxylubimin was the predominant phytoalexin formed after treatment of the fruits with arachidonic acid, cellulase and the P. infestans preparation. Copper sulphate was a potent elicitor of lubimin but not 3-hydroxylubimin. The fungus P. chrysogenum metabolized lubimin and 3-hydroxylubimin to 15-dihydrolubimin and 3-hydroxy-15-dihydrolubimin respectively, both in fruit cavities inoculated with spores of this fungus and in pure culture. The 15-dihydrolubimin formed in the fruits by the fungus was further metabolized (by the fruits) to both isolubimin and 3-hydroxy-15-dihydrolubimin. The precursor-product relationships between all of the subject compounds was investigated by feeding experiments with (3)H-labelled compounds. 2-Dehydro-[15-(3)H1]lubimin was rapidly and efficiently incorporated into lubimin and may be the direct precursor of lubimin in planta. 3-Hydroxy[2-(3)H1]lubimin was incorporated into the nor-eudesmane rishitin but 10-epi-3-hydroxy[2-(3)H1]lubimin was not. An updated scheme for the biosynthesis and metabolism of lubimin and related compounds in infected tissues of solanaceous plants is presented.

The physical maps for sequencing human chromosomes 1, 6, 9, 10, 13, 20 and X.

We constructed maps for eight chromosomes (1, 6, 9, 10, 13, 20, X and (previously) 22), representing one-third of the genome, by building landmark maps, isolating bacterial clones and assembling contigs. By this approach, we could establish the long-range organization of the maps early in the project, and all contig extension, gap closure and problem-solving was simplified by containment within local regions. The maps currently represent more than 94% of the euchromatic (gene-containing) regions of these chromosomes in 176 contigs, and contain 96% of the chromosome-specific markers in the human gene map. By measuring the remaining gaps, we can assess chromosome length and coverage in sequenced clones.