Drought and the consequences of El Niño in Borneo: a case study of figs

Borneo has a perhumid climate but occasional severe droughts have an important impact. Droughts may affect the composition and size structure of plant communities through differential mortality or, via their impact on the availability of plant resources, affect plant–animal interactions. From January to April 1998, northern Borneo suffered a very severe drought linked to the El Niño Southern Oscillation event of 1997–1998. In this article, the impacts of this drought on the rain forest at Lambir Hills National Park, Sarawak, are considered with special reference to a keystone plant group, the figs. Small fires entered the edge of the forest from the roadside, killing saplings, climbers, and understory trees. Community-wide mortality for adult trees was 0–7 times higher than in nondrought years, with larger trees showing a greater proportional increase. In figs, mortality was significantly higher in pioneers, but hemiepiphytes and roadside species were unaffected. Phenology was substantially affected. Leaf and flower/fruit production decreased or ceased during the drought and increased suddenly following renewed rain. Pollinators of dioecious figs became locally extinct during the drought, and other plant–animal interactions may also have been disrupted. The frequency and severity of droughts has increased substantially in the past three decades, and climate models suggest this may be the result of global warming. The impacts of the 1998 drought at Lambir Hills National Park suggest that, should this trend continue, a substantial alteration of habitats and overall loss of biodiversity can be expected in Borneo.     

Patterns in the epilithic community of a lake littoral

1. The algae and sedentary macroinvertebrates on the upper surface of stones from the littoral of Crosemere were investigated over 13 months. This lake is one of a series of eutrophic meres of glacial origin in the English Midlands. 2. Stones were taken from shallow and deep areas in the littoral and from areas shaded by bankside trees and those away from trees. This gave four habitat types: open/shallow; open/deep; shade/shallow; shade/deep. Epilithic algae and sedentary macroinvertebrates from the upper surfaces of the stones were quantified monthly for each habitat type. 3. Chlorophyll a and ash-free dry mass both showed a strong seasonal pattern common to all habitat types, with a spring peak declining to a summer minimum, followed by a small autumn recovery, and a winter minimum. 4. In terms of percentage cover, Cladophora glomerata showed a markedly different pattern. There were strong differences between habitat types, with shaded stones from the shallows, in particular, having very sparse Cladophora cover. In the open, Cladophora cover was high in summer and low at other times. 5. The invertebrate community was dominated by retreat-dwelling larvae of the psychomyiid caddis, Tinodes waeneri, and four species of chironomids with tube-building larvae, Cricotopus sylvestris, Microtendipes pedellus, Glyptotendipes pallens and Endochironomus albipennis. For Tinodes, Cricotopus and Microtendipes, peaks of density occurred chiefly beneath trees in spring and summer. 6. The seasonal pattern of algal abundance showed little relationship with that of invertebrate biomass. The ratio of chlorophyll a to ash-free dry mass also declined in summer, despite the higher invertebrate biomass. This indicated that grazing was not the dominant factor diminishing algal abundance seasonally. It seems likely that algae were limited chiefly by physical factors, such as light and temperature, and by nutrients, particularly nitrates, which decline in summer in the epilimnion of the lake. 7. Grazing may have contributed to spatial patchiness of algae in summer, however, particularly that of Cladophora. The scarcity of Cladophora on shallow, shaded stones coincided with a high abundance of Tinodes on these stones in early summer. Riparian trees could thus have affected epilithic algae, not only by shading but also indirectly through the supply of grazers.     

The gastrointestinal absorption of organically bound forms of plutonium in fed and fasted hamsters

Values of about 0.005-0.01 per cent were obtained for the absorption in fed hamsters of plutonium ingested as Pu4+ citrate, isocitrate, phytate and malate complexes and Pu3+ ascorbate compared with about 0.003-0.004 per cent for Pu4+ nitrate. Replacing drinking water with tea did not affect the result for Pu4+ nitrate. Fasting hamsters for 8 h before the administration of plutonium citrate increased absorption to 0.1-0.2 per cent. An extra period of fasting for 4 h after administration did not lead to a further increase in absorption. Similar values were also obtained when plutonium citrate was administered after a 24 h fast, followed either by immediate access to food or a further 4 h fast. In hamsters fasted for 24 h before administration of either Pu3+ ascorbate or Pu4+ nitrate, about 6-7 per cent of the ingested plutonium was retained in the gastrointestinal tract after one week. At three weeks after ingestion of Pu3+ ascorbate, gastrointestinal retention had fallen 100-fold without an increase in absorption.     

Can telemedicine be used to improve communication between primary and secondary care?

OBJECTIVE: To test feasibility and acceptability of teleconferencing routine outpatient consultations. DESIGN: Exploratory trial of teleconferenced outpatient referrals of general practitioners. SETTING: An inner city teaching hospital and surrounding general practices. SUBJECTS: Six general practices linked to hospital outpatient clinics. MAIN OUTCOME MEASURES: Levels of participants'' satisfaction measured with self administered questionnaires. RESULTS: 54 teleconsultations were performed in 10 different specialties. Few serious technical problems were encountered, and high levels of satisfaction with the consultations were reported by patients, hospital specialists, and general practitioners. CONCLUSIONS: Teleconferenced consultations for routine outpatient referrals with joint participation of general practitioner were feasible. These may have an important potential benefit for improving communication between primary and secondary care.     

Full Inactivation of Human Influenza Virus by High Hydrostatic Pressure Preserves Virus Structure and Membrane Fusion While Conferring Protection to Mice against Infection

Whole inactivated vaccines (WIVs) possess greater immunogenicity than split or subunit vaccines, and recent studies have demonstrated that WIVs with preserved fusogenic activity are more protective than non-fusogenic WIVs. In this work, we describe the inactivation of human influenza virus X-31 by high hydrostatic pressure (HHP) and analyze the effects on the structure by spectroscopic measurements, light scattering, and electron microscopy. We also investigated the effects of HHP on the glycoprotein activity and fusogenic activity of the viral particles. The electron microscopy data showed pore formation on the viral envelope, but the general morphology was preserved, and small variations were seen in the particle structure. The activity of hemagglutinin (HA) during the process of binding and fusion was affected in a time-dependent manner, but neuraminidase (NA) activity was not affected. Infectious activity ceased after 3 hours of pressurization, and mice were protected from infection after being vaccinated. Our results revealed full viral inactivation with overall preservation of viral structure and maintenance of fusogenic activity, thereby conferring protection against infection. A strong response consisting of serum immunoglobulin IgG1, IgG2a, and serum and mucosal IgA was also detected after vaccination. Thus, our data strongly suggest that applying hydrostatic pressure may be an effective method for developing new vaccines against influenza A as well as other viruses.