THE FEASIBILITY OF USING VERTICAL-LOOKING RADAR TO MONITOR THE MIGRATION OF BROWN PLANTHOPPER AND OTHER INSECT PESTS OF RICE IN CHINA

Abstract The recent development of automatically operating, inexpensive vertical-looking radar (VLR) for entomological purposes has made it practical to carry out routine, automated monitoring of insect aerial migration throughout the year. In this paper we investigate whether such radars might have a role in monitoring and forecasting schemes designed to improve the management of the Brown Planthopper (BPH), Nilaparvata lugens , and of associated rice pest species in China. A survey of the literature revealed that these insects typically migrate at altitudes between 300 to 2 000 m above ground level, but calculations based on BPH radar scattering cross-sections indicated that the maximum altitude at which they individually produce signals analysable by current VLRs is only ˜ 240 m. We also show that coverage over most of the flight altitudes of BPH could be achieved by building a VLR using a wavelength of 8.8 mm instead of the 3.2 cm of existing VLR, but that such a radar would be expensive to build and to operate. We suggest that a more practical solution would be to use a 3.2 cm VLR as a monitor of the aerial movement of the larger species, from which the migration of rice pests in general might be inferred.     

Endotoxemia and hepatic injury in a rodent model of hindlimb unloading.

Hindlimb unloading (HU) is known to induce physiological alterations in various organ systems that mimic some responses observed after exposure to microgravity. In the present study, the effects of up to 4 wk of HU on the liver were assessed in male Wistar rats and two mouse strains: endotoxin-sensitive C57BL/6 mice and endotoxin-resistant C3H/HEJ mice. Plasma levels of endotoxin, a known stimulator of hepatic injury, were measured in portal and systemic blood samples. Endotoxin was elevated by approximately 50% in portal blood samples of mice and rats but was not detectable in systemic blood. This low-grade portal endotoxemia was associated with hepatic injury in rats and C57BL/6 mice as indicated by inflammation and elevated serum transaminase activities. Blood levels of the cytokine TNF-alpha were increased by approximately 50% in C57BL/6 mice; no significant elevation of this cytokine was detected in rats. Messenger RNA levels of the acute-phase proteins serum amyloid A, haptoglobin, and lipopolysaccharide binding protein were significantly enhanced after 3 wk of HU in endotoxin-sensitive rodents. In contrast, no histological changes or significant increases in serum enzyme activity were detected after HU in C3H/HEJ mice despite portal endotoxin levels of 222 +/- 83.4 pg/ml. At the 3-wk time point, expression of acute-phase proteins was not elevated in C3H/HEJ mice; however, expression after 4 wk of HU was similar to endotoxin-sensitive rodents. In conclusion, these findings indicate that HU induced mild portal endotoxemia, which contributed to the observed hepatic injury in endotoxin-sensitive rodents.     

OCCURRENCE OF AN ISOPRENOID C25 DIUNASATURATED ALKENE AND HIGH NEUTRAL LIPID CONTENT IN ANTRACTIC SEA-ICE DIATOM COMMUNITIES1

The lipid and hydrocarbon composition of natural populations of diatom communities collected during the austral spring bloom of 1985 in the sea-ice at McMurdo Sound, Antartica was analyzed by TLC-FID, GC and GC-MS. Sea-ice diatom communities were dominated by Amphiprora sp., Nitzschia stellata Manguin and Berkeleya sp. at Cape Armitage; N. stellata, Amphiprora, Pleurosigma, N. kerguelensis (O'Meara) Hasle and some small centric diatoms adjacent to the Erebus Ice Tongue; and Porosira pseudodenticulata (Hustedt) Jouse at Wohlschlag Bay. Lipid distributions of the sea ice diatom communities from the Cape Armitage and Ereus sites were characterized by high concentrations of tracylaglecycerol (triacylglycerolplar lipid = 1.0 to 1.5). The hydrocarbon n-C_21:6, common in temperate diatoms, and an isoprenoid C₂₅ diunsaturated alkene were the dominant hydrocarons detected at these two sites. Hydrogenation of the C₂₅ diene produced the known alkane 2, 6, 10, 14-tetramethyl-7- (3-methylpentyl)-pentadecane. The C₂₅ diene is one of several structurally related hydrocarbons reported in many estuarine, coastal and ocean ic sediments. We propose that certain species of diatoms are a likely source of these alkenes in sediments. The first reported biological occurrence of the C₂₅ diene in the green seaweed Enteromorpha prolifera may have been due to the presence of epiphytic microalgae in the field sample analysed.     

Expression of p21ras-related protein in the plasma and tissue of patients with adenomas and carcinomas of the colon

Over-expression of p21 ras-related protein was determined in the plasma by immunoblotting and in the tissue by immuno-histochemistry in a cohort of patients undergoing colonoscopy. In the plasma samples, p21 ras over-expression was detected in: 9% (4/47) of normal controls; 21% (13/61) of individuals with normal colonoscopies but with a prior history of colonic neoplasia; 12% (4/33) of small adenoma patients, 29% (6/21) of large adenoma patients; 63% (5/8) of carcinoma-in-adenoma patients; 50% (2/4) of Dukes' A carcinoma patients; and 20% (2/10) of Dukes' B-D carcinoma patients. In the tissue samples, p21 ras over-expression was detected in: 25% (2/8) of small adenoma patients; 44% (4/9) of large adenoma patients; 100% (4/4) of carcinoma-in-adenoma patients; and 33% (1/3) of Dukes' B-C carcinoma patients. For matched plasma-tissue pairs, there was a statistically significant correlation for p21 ras over-expression (R = 0.47, p = 0.02).     

Combining specialist and primary health care teams for HIV positive patients: retrospective and prospective studies.

OBJECTIVE: To develop and evaluate a model of health care for HIV positive patients involving specialist, hospital based teams and primary health care teams. DESIGN: One year retrospective and a 2 1/2 year prospective study. SETTING: Two hospitals in West London and 88 general practitioners in 72 general hospitals. SUBJECTS: 209 adults with HIV infection. INTERVENTION: General practitioners enrolled in the project were faxed structured outpatient clinic summaries. When hospital inpatients were discharged, a brief discharge summary was faxed. General practitioners had access to consultant physicians skilled in HIV medicine through a 24 hour mobile telephone service. An HIV/AIDS management and treatment guide containing relevant local information was produced. Quarterly discussion forums for general practitioners were held, and a regular newsletter was produced. MAIN OUTCOME MEASURES: Hospital attendance and general practitioner consultations; perceived benefits and problems of patients and general practitioners. RESULTS: The average length of a hospital inpatient stay was halved for those patients who had participated in the project for two years, and the average number of visits to the outpatient clinic per month fell for patients with AIDS. There was a substantial increase in the number of visits to general practitioners by patients with AIDS and symptomatic HIV infection. Patients and general practitioners both felt that the standard of health care provided had improved. CONCLUSIONS: This model of health care efficiently and effectively utilised existing teams of hospital and primary health care professionals to provide care for HIV positive patients. Simple, prompt, and regular communication systems which provided information relevant to the needs of general practitioners were central to its success.