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A long-term field experiment in limestone grassland near Buxton (North Derbyshire, United Kingdom) was designed to identify plant attributes and vegetation characteristics conducive to successful invasion. Plots containing crossed, continuous gradients of fertilizer addition and disturbance intensity were subjected to a single-seed inoculum comprising a wide range of plant functional types and 54 species not originally present at the site. Several disturbance treatments were applied; these included the creation of gaps of contrasting size and the mowing of the vegetation to different heights and at different times of the year. This paper analyzes the factors controlling the initial phase of the resulting invasions within the plots subject to gap creation. The susceptibility of the indigenous community to invasion was strongly related to the availability of bare ground created, but greatest success occurred where disturbance coincided with eutrophication. Disturbance damage to the indigenous dominants (particularly Festuca ovina) was an important determinant of seedling establishment by the sown invaders. Large seed size was identified as an important characteristic allowing certain species to establish relatively evenly across the productivity-disturbance matrix; smaller-seeded species were more dependent on disturbance for establishment. Successful and unsuccessful invaders were also distinguished to some extent by differences in germination requirements and present geographical distribution.

Visual impairment is commonly reported as a consequence of heavy prenatal ethanol exposure in humans. Children generally display characteristic cranio-facial dysmorphology and represent typical severe cases of foetal alcohol syndrome. Binge-like rodent model systems have concluded that third trimester equivalent ethanol exposure results in widespread apoptosis in the visual system from the retina to the visual cortex. Neither clinical nor animal studies address the consequences of more moderate prenatal ethanol exposure on the visual system. The current study uses a naturalistic and voluntary consumption approach in non-human primates (Chlorocebus sabeus) in order to more closely model prenatal ethanol consumption patterns in humans. Pregnant vervet monkeys voluntarily drank on average 2.418 ± 0.296 g etoh/kg/day four times a week during the third trimester. Using unbiased stereology, we estimated the neuronal and glial population of the parvocellular (P) and magnocellular (M) layers of the lateral geniculate nucleus (LGN) following foetal alcohol exposure (FAE) in infant subjects. Layer volume and total number of neurons and glia in the LGN of the FAE subjects were not significantly different from age-matched control subjects. The M neuronal soma size of FAE subjects, however, was significantly reduced to resemble the size of the P-neurons. These results suggest that alterations at the level of morphology and anatomy of the M-neurons may lead to behavioural deficits associated with the integrity of the dorsal visual pathway.

Signal transducers and activators of transcription (STATs) are transcription factors activated in response to cytokines and growth factors. Constitutively active Stat3 has been shown to mediate oncogenic transformation in cultured cells and induce tumor formation in mice. An increasing number of tumor-derived cell lines as well as samples from human cancer have been reported to express constitutively active Stat3 protein. We previously demonstrated that ovarian cancer cell lines express high levels of constitutively active Stat3. In this study, we show that inhibition of the Stat3 signaling pathway using the Janus Kinase-selective inhibitor, AG490, and a dominant negative Stat3 (Stat3beta) significantly suppresses the growth of ovarian and breast cancer cell lines harboring constitutively active Stat3. In the ovarian cancer cell lines, AG490 also diminished the phosphorylation of Stat3, Stat3 DNA binding activity, and the expression of Bcl-x(L). Further, AG490 induced significant apoptosis in ovarian and breast cancer cell lines expressing high levels of constitutively active Stat3 but had a less profound effect on normal cells lacking constitutively active Stat3. AG490 also enhanced apoptosis induced by cisplatin in ovarian cancer cells. These results suggest that inhibition of Stat3 signaling may provide a potential therapeutic approach for treating ovarian and breast cancers.

1 A dwarf shrub heath in subarctic Sweden was subjected to factorial manipulation of air temperature, water and nutrient supply for 5 years. The responses of the vegetation to the perturbations were then assessed by point intercept (quadrat) analysis followed by determination of above-ground biomass. 2 Nineteen vascular and 23 non-vascular species (or species groups) were recorded and the most dramatic response was that of the grass Calamagrostis lapponica to nutrient addition, with abundance being stimulated by a factor of more than 18 compared with plots not subjected to nutrient addition. Calamagrostis lapponica did not show any significant responses to temperature or water alone but there was a synergistic interaction between all three variables. 3 The abundance of the dominant dwarf shrubs (Empetrum hermaphroditum, Vaccinium vitis-idaea, V. myrtillus and V. uliginosum) was unaffected by the perturbations but elevated temperature stimulated the biomass of V. uliginosum by 125% and total shrub biomass by 16%. The low ratio of current year's growth to standing biomass may have concealed other responses of the dwarf shrub group to the perturbations. 4 The response of the non-vascular flora to the perturbations was either neutral or negative, with lichens showing the most dramatic responses. Lichen biomass on temperature- and nutrient-amended plots was 56% and 18%, respectively, of that on unperturbed plots. Nutrients also exerted a negative effect on the biomass of bryophytes, and the combined biomass of lichens and bryophytes on nutrient-treated plots was almost a third of that on plots which did not receive additional nutrients. 5 Total above-ground biomass was not affected by the perturbations but the total number of interceptions determined by point quadrat analysis was greater on the elevated temperature and nutrient-treated plots. Point quadrat analysis also revealed an accumulation of litter and standing dead material in response to the nutrient and temperature perturbations, both singly and in combination, suggesting a faster turnover of plant material. 6 Both temperature and nutrients increased canopy height and also interacted synergistically such that together they resulted in a mean canopy height of 14.9 cm compared with 8.0 cm in plots subjected to neither perturbation. 7 Nutrient addition lowered species richness by 17.7%, mainly through its impact on the mosses and lichens. 8 In general, nutrient addition elicited the greatest response, followed by temperature, with water exerting little measurable influence. There were a number of important interactions that were often synergistic, and some involved water. 9 Species' responses were highly individualistic and changes in the community were mediated through the response of a small number of key species already present in the community, with no invasion of new species. In the short term at least, floristic diversity may decline as understorey species become less abundant and immigration by new species is inhibited by the dominance of clonal angiosperms.

A group of pharmacy, medical, and law students at three universities in the Ohio River Valley were surveyed during the spring and fall of 1969 regarding their attitudes toward the control of psychoactive substances. Responses were obtained from 1,586 or 84.3 percent of the group. The majority of students agreed with the current control of most psychoactive substances, but many favored a change in the legal control of marijuana (62.4 percent) and heroin (51.6 percent). Students favoring change in the current control of these substances tended to be less traditional in their religious beliefs, had more knowledge concerning psychoactive substances, and had at least one prior experience with the use of marijuana. There was strong rejection of a punitive approach toward controlling the use of psychoactive substances.