9000 years of change in coral community structure and accretion in Belize reefs, western Atlantic.

Tropical coral reefs, as prominent marine diversity hotspots, are in decline, and long-term studies help to improve understanding of the effects of global warming, sea-level rise, ocean acidification, deterioration of water quality, and disease. Here, we evaluated relative coral abundance and reef accretion rates over the past 9000 years in Belize barrier and atoll reefs, the largest reef system in the Atlantic Ocean. Acropora palmata and Orbicella spp. have been the most common corals. The abundance of competitive, fast-growing acroporids was constant over multi-millennial timescales. A decline in A. cervicornis abundance, however, and three centennial-scale gaps in A. palmata occurrence, suggest that the modern decline in acroporids was not unprecedented. Stress-tolerant corals predominate at the beginning of Holocene successions. Following the improvement of environmental conditions after inundation of the reef pedestal, their abundance has decreased. The abundance of weedy corals has increased during the Holocene underlining the importance of fecundity for the coral community. Reef-accretion rate, as calculated based on 76 new U-series age dates, has decreased over the Holocene and the mean value of 3.36 m kyr-1 is at the lower end of global reef growth compilations and predicted future rates of rise in sea level.

Remediation of sandy soils using surfactant solutions and foams.

Remediation of sandy soils contaminated with diesel oil was investigated in bench-scale experiments. Surfactant solution, regular foams and colloidal gas aphrons were used as remediation fluids. An experimental design technique was used to investigate the effect of relevant process variables on remediation efficiency. Soils prepared with different average particle sizes (0.04-0.12 cm) and contaminated with different diesel oil contents (40-80 g/kg) were used in experiments conducted with remediation fluids. A mathematical model was proposed allowing for the determination of oil removal rate-constant (k(v)) and oil content remaining in the soil after remediation (C(of)) as well as estimation of the percentage of oil removed. Oil removal efficiencies obtained under the central experimental design conditions were 96%, 88% and 35% for aphrons, regular foams and surfactant solutions, respectively. High removal efficiencies were obtained using regular foams and aphrons, demanding small amounts of surfactant.

Suppressing spatiotemporal disorder via local perturbations in an electrochemical cell.

We report experimental results depicting suppression of complex spatiotemporal dynamics under the influence of local periodic stimulations. In an experimental electrochemical system, applying a continuous forcing signal to one of the sites in an array of eight coupled oscillators, the naturally complex behavior of the remaining seven electrodes can be converted to periodic responses. The oscillations remain periodic as long as the forcing is active and revert back to exhibiting chaotic dynamics after the control is switched off. These results can also be interpreted as experimental realization of "phase-synchronization" induced via local driving in an extended system. A possible relevance to the experimentally observed calcium wave patterns is pointed out.

Controlling spatiotemporal chemical chaos using delayed feedback.

Control of chemical chaos in a spatially extended system mimicking CO oxidation on a Pt(110) single-crystal surface is achieved using delayed feedback techniques. For appropriate parameter values the uncontrolled model system exhibits both amplitude and phase turbulence. Superimposing a delayed feedback on the natural dynamics, suppression of spatiotemporal complexity is attained via stabilization of ordered states consisting of stable patterns.

Antiviral and antimicrobial activities of Colombian medicinal plants.

Strong antiviral and antimicrobial activities were detected in methanolic extracts of 24 plants used medicinally in the treatment of skin infections in four different regions of Colombia. Thirteen extracts displayed activity against herpes simplex virus (HSV) whereas none was active against poliovirus. The antiviral activity was indicated by a total inhibition of viral cytopathic effects (CPE) at a non-cytotoxic concentration of the extract. The most potent extract was obtained from Byrsonima verbascifolia (L.) HBK. which showed anti-HSV activity at a concentration as low as 2.5 microg/ml. Antimicrobial screening was conducted using the disc diffusion assay against Klebsiella pneumoniae, Escherichia coli, Streptococcus faecalis, Mycobacterium phlei, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium and the human pathogenic yeast, Candida albicans. Anti-Candida activity was observed for Piper lanceaefolium HBK. and Juglans neotropica Diels. Twenty-two extracts displayed activity against Gram-positive bacteria whereas none was active against the Gram-negative species. We concluded that these Colombian medicinal plants represent an untapped source of potentially useful antivirals and are worthy of further study.

The effect of high altitude on platelet counts, thrombopoietin and erythropoietin levels in young Bolivian airmen visiting the Andes.

Recognition of thrombosis as a complication of exposure to high altitude has stimulated interest in rheological changes resulting from hypobaric hypoxia. Previous studies of platelet counts at high altitude have yielded conflicting results and have not been studied in conjunction with potential mediating cytokines. We studied the effects of high-altitude exposure on platelet numbers, thrombopoietin (tpo) and erythropoietin (epo) levels in man. A group of 28 volunteers from the Bolivian Airforce stationed at Santa Cruz (600 m altitude) were studied 48 h and 1 week after their ascent to La Paz (3600 m). In addition 105 volunteers based at Santa Cruz for at least 1 year were compared with 175 age- and sex-matched residents at El Alto (4200 m). Platelet counts were measured immediately after sampling and serum samples assayed for tpo and epo. In the ascending group, mean platelet counts were 251 x 10(9), 367 x 10(9) and 398 x10 (9)/l at 600 m and following 48 h and 1 week at 3600 m respectively. Mean tpo levels were 132.5, 76 and 92 pg/ml with epo values of 2.98, 11.6 and 7.9 mIU/ml respectively. In the resident populations mean platelet counts were 271 x 10(9)/l in the low- and 471 x 10(9)/l in the high-altitude groups. Mean tpo and epo levels measured 69.3 pg/ml and 4.5 mIU/ml respectively at 600 m and 58.5 pg/ml and 5.1 mIU/ml at 4200 m. In conclusion we have demonstrated a significant and sustained elevation in platelet numbers within 48 h of ascent to high altitude. Our findings do not support a role for tpo as a mediator of the increased platelet count. However, these data do not discount epo as a potential candidate.

A chlamydial major outer membrane protein extract as a trachoma vaccine candidate.

PURPOSE: As shown in infected humans and in animal models of chlamydial infection, the major outer membrane protein (MOMP) of Chlamydia trachomatis is immunogenically potent. The purpose of this investigation was to test in the cynomolgus monkey model of trachoma a new extract of MOMP as a candidate vaccine against ocular chlamydial infection. METHOD: The nonionic detergent octyl-beta-D glucopyranoside (OGP) was used to extract MOMP from purified C. trachomatis (serovar C) elementary bodies. Protective immunization with OGP-MOMP by mucosal and systemic routes was compared in the cynomolgus monkey model of trachoma. All control and immunized monkeys were challenged by topical application of infectious C. trachomatis to the conjunctivae 35 days after the initiation of immunization. RESULTS: Immunization with OGP-extracted MOMP successfully induced chlamydia-specific local and systemic immunity to MOMP and to whole organism before challenge and early clearance of infection by systemically immunized monkeys. Although ocular disease was not significantly reduced in either immunized group compared to control animals, the lowest clinical and microbiologic disease scores developed in two animals in the mucosal group with the highest immunoglobulin A tear antibody titers at day 0 to 14, whereas higher tear and serum immunoglobulin G correlated with reduced disease in the systemically immunized group. CONCLUSIONS: These data demonstrate that despite evidence of vigorous MOMP-specific and other chlamydia-specific serologic and cell-mediated immunity, as well as anamnestic serologic responses to chlamydia, vaccination with OGP-MOMP was only partially protective against chlamydial ocular disease. The partial protection correlated best with tear immunoglobulin A responses after mucosal immunization and with local and systemic immunoglobulin G responses after peripheral immunization, suggesting that alternative chlamydial antigens may have to be considered in future vaccine development to induce more effective protective immunity and that evaluation of efficacy must be appropriate to route of immunization.

Childhood sexual abuse and bulimia nervosa: a comparison of American, Austrian, and Brazilian women.

OBJECTIVE: This study was designed to assess the prevalence of childhood sexual abuse among women with bulimia nervosa in three countries: the United States, Austria, and Brazil. In addition, it assessed whether bulimic subjects might have experienced more severe sexual abuse than women in the general population and whether bulimic subjects who report abuse might display greater psychopathology than those who do not report abuse. METHOD: Thirty-three university students in Innsbruck, Austria, 33 university students in Boston, and 25 women in São Paulo, Brazil, all meeting DSM-III-R criteria for bulimia nervosa, were recruited by advertisement. Detailed histories of sexual abuse, obtained at the conclusion of a comprehensive evaluation interview, were prepared, translated into English, and rated by an investigator who was blind to the nationality of the subject. Subjects were compared on frequency of eating binges, history of major depression, body mass index, and satisfaction with body image. RESULTS: Narrowly defined childhood sexual abuse was reported by 24%-36% of women in the three countries, although only 15%-32% of women reported abuse before the onset of bulimia nervosa. There were no significant differences between countries in rates of abuse. Overall, these rates appear no greater than those reported in comparable studies of women in the general population. The data also did not support the hypothesis that bulimic subjects had endured more severe sexual abuse than other women, nor was there a significant association between history of childhood sexual abuse and severity of bulimic symptoms. CONCLUSIONS: These findings add to the weight of evidence suggesting that childhood sexual abuse is not a risk factor for bulimia nervosa.

[Biloma]. / Biloma.

The Term "Biloma" describes an extraductular collection of bile within a defined capsular space secondary to traumatic, iatrogenic or spontaneous injury of the biliary tree, of medical, surgical or mixed treatment.

Studies on the pharmacological activity of Amazonian Euphorbiaceae.

Plant material from 34 Amazonian species of the family Euphorbiaceae were collected and extracts prepared. Sixteen of these species have a documented use as a medicinal agent. The extracts were tested for their ability to inhibit the growth of the bacteria, Escherichia coli and Staphylococcus aureus; the yeasts, Saccharomyces cerevisiae and Candida albicans; the dermatophytic fungi, Microsporum canis, Microsporum fulvum, Microsporum gypseum and Trichophyton gallinae; the viruses, Sindbis virus and murine cytomegalovirus; and tumours induced on potato discs by Agrobacterium tumefaciens. They were also examined for their toxicity to brine shrimp, Artemia salina. The results are discussed with respect to ethnobotanical information available for some of the species.

La campaña de emergencia mediante rociamientos en volumenes ultrarreducidos contra ejemplares adultos de Aedes aegypti realizada en 1982 en Paramaribo, Suriname / Emergency campaign by ultralow volume sprayers against adult. Aedes aegypti samples carried out during 1982 in Paramaribo, Suriname

En un intento de detener una epidemia de dengue en la ciudad de Paramaribo, se efectuaron en mayo y junio de 1982 rociamientos con malatión al 95%, aplicado con pulverizadores de volumen ultrarreducido (ULV) montados en camiones. Toda la ciudad, con una superficie de 70 Km**2 y 552 km de calles, fue rociada dos veces en 37 noches de un período de siete semanas y media, utilizando dos pulverizadores durante cuatro horas cada noche (18.00 a 22.00 horas), con un intervalo de una semana entre los dos rociamientos de cada zona. Durante las tres primeras semanas de la campaña, una dosis de 456 ml de ingrediente activo por Km de calle (50 ml/ha si la amplitud de barrido era de 91 m) produjo una gran mortalidad de Aedes aegypti adultos colocados en jaulas en el interior y en el exterior de los edificios de una manzana rociada; sin embargo, los resultados de las pruebas con trampas de ovipostura indicaron únicamente una pequeña reducción del número de huevos y solo durante unos tres días después de la aplicación de aerosol. Por consiguiente, se incrementó la dosis a 901 ml/Km (99 ml/ha) en las semanas 4-7, pero en una segunda zona de prueba se encontró que el número de trampas con huevos se reducía muy poco y durante un período breve. Por lo tanto, parece que ninguna de las dosis fue adecuada para eliminar la población adulta de A. aegypti y, además, que el método de aplicación fue demasiado lento para detener la epidemia de dengue, objetivo de la campaña

La campaña de emergencia mediante rociamientos en volúmenes ultrarreducidos contra ejemplares adultos de Aedes aegypti realizada en 1982 en Paramaribo, Suriname / The 1982 emergency ultralow volume spray campaign against Aedes aegypti adults in Paramaribo, Suriname

In an attempt to stop an epidemic of dengue, the city of Paramaribo was sprayed in May and June 1982 with 95

malathion from truck-mounted ultralow volume (ULV) sprayers. The entire city, with an area of 70 square kilometers and 552 kilometers of roads, was sprayed twice on 37 evenings spread over seven and a half weeks by two sprayers working four hours each evening (1800-2200 hours), there being a one-week interval betweeen the two sprayings in each zone. During the first three weeks of the campaign, a dosage of 456 ml active ingredient per km of road (50 ml/ha if the swath width was 91 m) gave high kills of Aedes aegypti adults caged indoors and outdoors on a sprayed block; but ovitrap results showed only modest reduction of egg-laying, and even that for only about three days after the spray application. The dosage was therefore increased to 901 ml/km (99 ml/ha) in weeks 4-7, but in a second test area the number of positive ovitraps was again reduced only modestly for a short period. It thus appears that neither dosage was adequate to suppress the adult A. aegypti population, and also that the method of application was too slow to stop the targeted dengue epidemic

Este artículo esta publicado en ingles en el Bull. Pan Am. Health Organ 20(3):294-303, 1986