Behavioral effects in monkeys of racemates of two biologically active marijuana constituents

Both dl-Delta(8)- and dl-Delta(9)-tetrahydrocannabinol produced marked alterations of behavior in rhesus and squirrel monkeys. Squirrel monkeys appeared to have visual hallucinations. Continuous avoidance behavior of squirrel monkeys was stimulated by both drugs, but high doses of dl-Delta(9)-tetrahydrocannabinol also caused depression after the stimulant phase. Complex behavior involving memory and visual discrimination in rhesus monkeys was markedly disrupted by both drugs.     

Large-scale changes in the abundance of common higher plant species across Britain between 1978, 1990 and 1998 as a consequence of human activity: Tests of hypothesised changes in trait representation

Presence of higher plant species was recorded in 1455 permanently marked quadrats located across Britain in 1978, 1990 and 1998 in a stratified, random sample of 259 1 km squares. Significant increases and decreases in frequency of each species were summarised as changes in the representation of simple traits, each of which had an established relationship with varying levels of fertility or disturbance. By testing the null hypothesis that the trait values represented among increasing or decreasing species were a random draw from the 1978 species pool, we determined the consistency of botanical change with changes in land-use in different vegetation types and landscape locations across Britain.Overall, 63% of significant changes in species occupancy were decreases and 37% increases. Trait changes were largely consistent with the impact of increased nutrient availability across vegetation types associated with inherently low fertility, such as infertile grassland, heath, bog and moorland. Linear habitats in lowland Britain saw trait changes consistent with secondary succession. Although trait changes were highly consistent with eutrophication in upland vegetation, the identity of the changing species left open the possibility that increased N deposition, sheep grazing intensity and local improvement could all have played a part.Recent changes in common plant species across Britain suggest that objectives for large-scale restoration and maintenance of plant communities must address four problems: (a) the increasing scarcity of stress-tolerant species in lowland species pools, (b) exploitation and maintenance of species populations on habitat fragments and linear features in the lowlands, (c) the spread and persistence of generalist species in upland Britain, (d) systemic nutrient enrichment in both lowland and upland environments.     

Increased crop yields following application of Bacillus penetrans to field plots infested with Meloidogyne incognita

We found Bacillus penetrans to be pathogenic to Meloidogyne incognita under field conditions. B. penetrans was added to the soil of field plots into which tobacco, soybeans or winter vetch were planted in sequence during 1981 and 1982. Tobacco and winter vetch (1981 and 1982) and soybeans in 1982 showed trends of increasing yields with decreasing pathogenicity of M. incognita. There was insufficient evidence to enable one to declare a similar trend for soybeans in 1981. B. penetrans reduced yield losses caused by M. incognita 23% for tobacco 1981, 38% for winter vetch 1981, 24% for tobacco 1982, 35% for soybeans 1982 and 55% for winter vetch 1982.     

The effect of sampling time and sample handling on the detection of Staphylococcus aureus in milk from quarters with subclinical mastitis

Staphylococcus aureus mastitis is an important cause of economic loss for the dairy industry. Control programs rely on the timely and accurate identification of positive quarters. The effects of sampling time and sample handling were examined in an attempt to improve the accuracy of detection of S. aureus. Premilking and postmilking milk samples were collected from 55 lactating quarters with subclinical S. aureus infection. Each sample was divided into 2 aliquots; one of which was cultured fresh, the other was frozen at -20 degrees C for 14 days before being cultured. Analysis of variance was used to determine the effect of sampling time (premilking vs postmilking) and sample handling (fresh vs frozen) on the detection of S. aureus, as measured by the mean category for colony-forming units per millilitre (cfu/mL). A stratified analysis was required, due to interaction between sampling time and sample handling. Only a fresh postmilking sample was inferior, yielding a lower mean category for cfu/mL (P < 0.05). The ability to detect S. aureus in quarters with subclinical intramammary infection, as measured by the mean category of cfu/mL, was maximized in fresh or frozen premilking samples and in frozen postmilking samples.     

Induction of plant defense gene expression by plant activators and Pseudomonas syringae pv. tomato in greenhouse-grown tomatoes

Plant activators provide an appealing management option for bacterial diseases of greenhouse-grown tomatoes. Two types of plant activators, one that induces systemic acquired resistance (SAR) and a second that activates induced systemic resistance (ISR), were evaluated for control of Pseudomonas syringae pv. tomato and effect on plant defense gene activation. Benzothiadiazole (BTH, SAR-inducing compound) effectively reduced bacterial speck incidence and severity, both alone and in combination with the ISR-inducing product. Application of BTH also led to elevated activation of salicylic acid and ethylene-mediated responses, based on real-time polymerase chain reaction analysis of marker gene expression levels. In contrast, the ISR-inducing product (made up of plant growth-promoting rhizobacteria) inconsistently modified defense gene expression and did not provide disease control to the same level as did BTH. No antagonism was observed by combining the two activators as control of bacterial speck was similar to or better than BTH alone.