Casimir forces out of thermal equilibrium near a superconducting transition

We present a comprehensive analysis of the out-of-equilibrium Casimir pressure between two high-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_c$$\end{document}Tc superconducting plates, each kept at a different temperature. Two interaction regimes can be distinguished. While the zero-point energy dominates in the near field, thermal effects become important at large interplate separations causing a drop in the force’s magnitude compared with the usual thermal-equilibrium case. Our detailed calculations highlight the competing role played by propagating and evanescent modes. Moreover, as one of the plates undergoes the superconducting transition, we predict an abrupt change in the force for any plate distance, which has not been previously observed in other systems. The sensitivity of the dielectric function of the high-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_c$$\end{document}Tc superconductors makes them ideal systems for a possible direct measurement of the out-of-equilibrium Casimir pressure.

Women's experiences using drugs to induce abortion acquired in the informal sector in Colombia: qualitative interviews with users in Bogotá and the Coffee Axis

In 2006, abortion in Colombia was decriminalised under certain circumstances. Yet some women continue to avail themselves of ways to terminate pregnancies outside of the formal health system. In-depth interviews (IDIs) with women who acquired drugs outside of health facilities to terminate their pregnancies (n = 47) were conducted in Bogotá and the Coffee Axis in 2018. Respondents were recruited when they sought postabortion care at a health facility. This analysis examines women's experiences with medication acquired outside of the health system for a termination: how they obtained the medication, what they received, how they were instructed to use the pills, the symptoms they were told to expect, and their abortion experiences. Respondents purchased the drugs in drug stores, online, from street vendors, or through contacts in their social networks. Women who used online vendors more commonly received the minimum dose of misoprostol according to WHO guidelines to complete the abortion (800 mcg) and received more detailed instructions and information about what to expect than women who bought the drug elsewhere. Common instructions were to take the pills orally and vaginally; most women received incomplete information about what to expect. Most women seeking care did not have a complete abortion before coming to the health facility (they never started bleeding or had an incomplete abortion). Women still face multiple barriers to safe abortion in Colombia; policymakers should promote better awareness about legal abortion availability, access to quality medication and complete information about misoprostol use for women to terminate unwanted pregnancies safely.

What does informal access to misoprostol in Colombia look like? A mystery client methodology in Bogotá and the Coffee Axis

INTRODUCTION

In 2006, abortion was decriminalised in Colombia under certain circumstances. Yet, women avail themselves of ways to terminate pregnancy outside of the formal health system. This study explored how drug sellers engage with women who attempt to purchase misoprostol from them.

METHODS

A mapping exercise was undertaken to list small-chain and independent drug stores in two regions in Colombia. A sample (n=558) of drug stores was selected from this list and visited by mystery clients between November and December 2017. Mystery clients sought to obtain a medication to bring back a delayed period, and described the experience, the information obtained and the medications proffered in exit interviews.

RESULTS

Misoprostol was offered for purchase in 15% of the visits; in half of visits, only information about misoprostol was shared, while no information about misoprostol was provided on the remaining visits. Over half of sellers who refused to sell any medication provided referrals, most commonly to an abortion provider. Among visits which included discussion of misoprostol, two out of five sellers provided dosage instructions with most recommending the minimum adequate dosage. Mystery clients received little information on the physical effects to expect with the use of misoprostol and possible complications.

CONCLUSIONS

As misoprostol is being obtained from some drug sellers without a prescription, capacitating this cadre with at least a minimum of standardised information on dosage, routes of administration and expected effects and outcomes have the potential to improve reproductive health outcomes for women who choose to terminate pregnancies this way in Colombia.

Near-field radiative heat transfer between high-temperature superconductors

Near-field radiative heat transfer (NFRHT) management can be achieved using high-temperature superconductors. In this work, we present a theoretical study of the radiative heat transfer between two [Formula: see text] (YBCO) slabs in three different scenarios: Both slabs either in the normal or superconducting state, and only one of them below the superconductor critical temperature [Formula: see text]. The radiative heat transfer is calculated using Rytov's theory of fluctuating electrodynamics, while a two-fluid model describes the dielectric function of the superconducting materials. Our main result is the significant suppression of the NFRHT when one or both of the slabs are superconducting, which is explained in terms of the detailed balance of the charge carriers density together with the sudden reduction of the free electron scattering rate. A critical and unique feature affecting the radiative heat transfer between high-temperature superconductors is the large damping of the mid-infrared carriers which screens the surface plasmon excitation.

Type 2 diabetes progression: A regulatory network approach

In order to elucidate central elements underlying type 2 diabetes, we constructed a regulatory network model involving 37 components (molecules, receptors, processes, etc.) associated to signaling pathways of pancreatic beta-cells. In a first approximation, the network topology was described by Boolean rules whose interacting dynamics predicted stationary patterns broadly classified as health, metabolic syndrome, and diabetes stages. A subsequent approximation based on a continuous logic analysis allowed us to characterize the progression of the disease as transitions between these states associated to alterations of cell homeostasis due to exhaustion or exacerbation of specific regulatory signals. The method allowed the identification of key transcription factors involved in metabolic stress as essential for the progression of the disease. Integration of the present analysis with existent mathematical models designed to yield accurate account of experimental data in human or animal essays leads to reliable predictions for beta-cell mass, insulinemia, glycemia, and glycosylated hemoglobin in diabetic fatty rats.

Abstract P2-02-04: Li-Fraumeni syndrome in females with early onset breast cancer in a Mexican population

Background: Breast cancer in Mexican patients presents in average 10 year earlier compared to other populations. Among patients with TP53 mutations, breast cancer is the most common malignancy. In this study we aim to determine the rate of TP53 mutations among young Mexican breast cancer patients.

Methods: Breast cancer patients younger that 45 were retrospectively identified, only patients without BRCA1/2 mutations were included. Clinical records and pedigrees were reviewed. Next generation sequencing test for TP53 was performed from blood specimens. All pathogenic mutations were confirmed by Sanger sequencing and verified if were included in the IACR TP53 database.

Results: Among the 78 patients younger than 45yo evaluated and tested with next generation sequencing, we identified 5 patients with a TP53 mutation (6.4%). All were younger than 36 corresponding to a rate of 9.4% of mutations in this group of individuals (n = 53). Two, not previously described, frameshift mutations were found (c.291delC and c.273dupG) and three missense mutations (c.844C>T, c.517G>A, c.604C>T). A VUS c.672G>A that causes a silent mutation in a splicing-donor site was identified. All patients with a TP53 mutation had locally advanced disease and tumors were high grade and Her2 positive.

Conclusions: Among Mexican women younger than 45yo, the rate of TP53 mutations was higher than in other populations where it's estimated to be 1%. Among patients younger than 36 the proportion was even higher. All patients had a family history suggestive of Li-Fraumeni syndrome. The VUS found in our series needs a deeper analysis (family segregation, structure and function of the resulting protein). Our results support the international recommendation of performing molecular testing for TP53 in breast cancer patients younger than 35 years. Identification of patients with TP53 mutation has important prognostic, therapeutic and quality of life implications for the proband in addition of the risk reduction strategies and intensive surveillance recommended in their families.

Citation Format: Gallardo-Alvarado LN, Cantu-De Leon DF, Tusie-Luna T, Tusie-Luna I, Diaz-Chavez J, Herrera EM, Chavez-MacGregor M, Bargallo-Rocha E, Villarreal C, Herrera.Montalvo LA, Segura-Kato YX. Li-Fraumeni syndrome in females with early onset breast cancer in a Mexican population [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-02-04.

Perfil del profesional nutricionista requerido por las instituciones empleadoras en la ciudad de Lima

Objetivos: Comprobar si las competencias profesionales, características y cualidades del nutricionista egresado de la EAP Nutrición están de acuerdo a las expectativas de las instituciones empleadoras. diseño: Estudio descriptivo, transversal, observacional. Institución: Facultad de Medicina, UNMSM. Participantes: Directivos de empleadoras de nutricionistas. intervenciones: A 28 instituciones empleadoras de nutricionistas egresados de la UNMSM, se aplicó una encuesta con el listado de competencias del plan curricular para cada área de desempeño profesional: Nutrición Clínica, Nutrición Pública, Servicios de Alimentación Colectiva y Deporte. Principales medidas de resultados: Competencias, características y cualidades, según áreas de desempeño profesional. Resultados: Todas las competencias en las diferentes áreas del listado fueron consideradas importantes para el desempeño del nutricionista. Además los encuestados recomendaron otras competencias necesarias para su institución. Respecto a las características y cualidades, no manifestaron preferencia por determinada edad o sexo, pero sí coincidieron en destacar la presentación y el trato personal, así como la iniciativa, en la práctica de la profesión. Conclusiones: El perfil de competencias del profesional definido por la Escuela de Nutrición para sus egresados estuvo de acuerdo a las expectativas de las instituciones empleadoras. Sin embargo, requeriría reforzar algunos aspectos en cada una de las áreas de desempeño, así como en la formación de valores y liderazgo.

Avian influenza in Mexico

The outbreak of highly pathogenic avian influenza (HPAI) H5N2 in Mexico in 1994 led to a clear increase in biosecurity measures and improvement of intensive poultry production systems. The control and eradication measures implemented were based on active surveillance, disease detection, depopulation of infected farms and prevention of possible contacts (identified by epidemiological investigations), improvement of biosecurity measures, and restriction of the movement of live birds, poultry products, by-products and infected material. In addition, Mexico introduced a massive vaccination programme, which resulted in the eradication of HPAI in a relatively short time in two affected areas that had a high density of commercial poultry.

In vitro cell fusion between CD4+ and HIV-1 Env+ T cells generates a diversity of syncytia varying in total number, size and cellular content

Syncytia formation in HIV infections is driven by the virus fusion-active molecules (Env) interacting with membrane components of hosts cells. HIV-syncytia are usually interpreted as pathogenic entities and although they may potentially vary in size, numbers and types of constituent cells, little is known about the extent and significance of their diversity. Here, we describe numerically the cell population dynamics and the diversity of syncytia produced in the in vitro cell-fusion between two Jurkat T cell lines, one CD4(+) and the other Env(+). Cell-fusion partners were differentially stained with the lipophilic DiI and DiO, or with the cytoplasmic CMFDA and CMTMR tracers and syncytia showing double fluorescence were counted in a flow cytometer. The total number of syncytia formed, their size, cellular complexity and ratio of CD4(+)/Env(+) cells recruited, varied significantly in relation with time of reaction and initial proportions of fusion partners. The considerable structural diversity of syncytia formed, in so limited an in vitro cell fusion reaction, suggests that a greater heterogeneity may be formed in the natural course of disease. Identification of the main determinants of syncytia diversity allows for a detailed study of the relation between the syncytia structure and function.

Experience in control of avian influenza in the Americas

The outbreaks of highly pathogenic avian influenza (HPAI) in Canada in 1966, the USA in 1984 and Mexico in 1994 led to a clear increase in biosecurity measures and improved intensive poultry production systems. In the past 12 years (1994-2006), there have been four outbreaks of HPAI on the American continent: in Mexico in 1994 (H5N2), in Chile in 2002 (H7N3), in the USA in 2004 (H5N2) and in Canada in 2004 (H7N3). In all cases, the control and eradication measures were based on prompt detection, depopulation of infected farms and epidemiological contacts, increased biosecurity measures and control of the movement of live poultry and their products, by-products and infected material. In Mexico, in addition to the aforementioned measures, the use of massive vaccination allowed eradication of HPAI in a relatively short time in two affected areas of high-density commercial poultry.

Measurement of atomic lifetimes with a mode-locked laser

We present a new technique for measuring atomic lifetimes with a mode-locked laser. A single laser pulse excites the atoms and a subsequent frequency-doubled pulse ionizes the excited-state atoms. The ions are collected and counted. The measurement is repeated using excitation and detection pulses with different time separations, which determines the excited-state decay rate. We demonstrated this technique for the 6P(3/2) state of cesium. The measured lifetime was 30.5 ns and had a statistical uncertainty of 0.1 ns. Systematic effects limited the overall experimental uncertainty to approximately 0.6 ns in this initial experiment.

Oriéntame: preventing and solving problems related to unwanted pregnancy for 25 years in Colombia

For over 25 years, the Oriéntame Foundation in Bogotá, Colombia, has been providing reproductive health services to women, regardless of their socio-economic or marital status, race, age or religious affiliation. Oriéntame started by focusing primarily on unwanted pregnancy and treatment for incomplete abortion, which has contributed to the reduction of maternal mortality in Bogotá. Oriéntame now provides comprehensive sexual and reproductive health services, including sexual health education, Pap smears, gynaecological problems, STIs and sexual violence, with a continuing emphasis on unwanted pregnancy, treatment for incomplete abortion and post-abortion care. The women that come to Oriéntame, some 18,000 per year in recent years, are from all socio-economic levels, and are increasingly more informed. The services are regularly re-evaluated so as to accommodate their changing needs. There is a sliding scale of fees, so that the 40% of women patients with higher incomes subsidize the 60% with lower incomes; this also allows the clinics to be self-supporting. Services are offered in an atmosphere of respect for women and their decisions, with professional staff who are trained to take care of both the medical and emotional needs of each woman. Since 1992, Oriéntame has also been doing outreach to the slum areas of Bogotá, providing education and information, to contribute to the empowerment of the poorest inhabitants of the city.

Anxiety: current practices in assessment and treatment of anxiety of burn patients

Anxiety is an affective response commonly experienced by persons after emotional and physical trauma, as well as associated with aversive medical treatments. The scientific information related to the conceptualization, assessment, and treatment of anxiety is limited. In order to develop a pilot protocol for anxiety management, nursing directors at 64 burn centers were surveyed. At 89% of the centers, anxiety measures were not used. Most of the teams assess informally through observation of patient (n=21), dialogue with patient (n=12), or both observation and dialogue with patient (n=15). Assessors of anxiety range in breadth from nurse only to the entire burn team, including pastoral care representatives and family. The class of medication most frequently endorsed in treating anxiety is the benzodiazipine, most often lorazepam (Ativan). A number of non-pharmacologic techniques are used to manage anxiety, e.g., muscle relaxation, breathing, imagery. Consideration should be given to assessing anxiety systematically, so knowledge can be gleaned and applied to conceptualization of symptom presentation and application of treatment resources.

Different prevalences of Plasmodium vivax phenotypes VK210 and VK247 associated with the distribution of Anopheles albimanus and Anopheles pseudopunctipennis in Mexico

The geographic distribution of Plasmodium vivax circumsporozoite protein phenotypes from patient blood used to infect colonized Anopheles albimanus and An. pseudopunctipennis was investigated in southern Mexico. Parasite phenotype types were determined in blood samples by a polymerase chain reaction and oligoprobe hybridization or by immunofluorescent assay of sporozoites. The proportion of infected mosquitoes and the number of oocysts per mosquito confirmed previous in vitro observations indicating that An. albimanus is more susceptible to VK210 and that An. pseudopunctipennis is more susceptible to VK247. All patients living on the coast were infected with VK210 and most patients living above 170 meters above sea level had VK247. Both phenotypes infected patients from intermediate altitudes. These results concur with the distribution of the anophelines, indicating that An. albimanus is the main vector of the phenotype VK210, but that An. pseudopunctipennis transmits both phenotypes. These conditions have direct implications on parasite transmission rates and malaria epidemiology in Mexico.

Mie scattering and the physical mechanisms of sonoluminescence

We propose an experimental procedure to investigate possible mechanisms for radiation emission in sonoluminescence. Our analysis is based on Mie's theory of light scattering for a coated sphere in an external medium. Depending on the physical mechanism responsible of sonoluminescence, the dielectric constant of the hot spot changes. As a case study we consider the problem of the detection of an inner plasma core in sonoluminescent bubbles. Our results show that polarization measurements of scattered light should discern the presence of a plasma provided that light detectors are fast enough. Extensions to other emission mechanisms are briefly discussed.

Imipramine treatment in pediatric burn patients with symptoms of acute stress disorder: a pilot study

OBJECTIVE

Pediatric burn patients often exhibit acute stress disorder (ASD) symptoms. Information on psychopharmacological treatment of ASD symptoms in children is scarce. This pilot study used a prospective, randomized, double-blind design to test whether thermally injured children suffering ASD symptoms benefit from imipramine.

METHOD

Twenty-five children, aged 2 to 19 years, received either imipramine or chloral hydrate for 7 days. A structured interview (clinically useful, but validity and reliability not yet established) was used to assess the presence and frequency of ASD symptoms both before treatment and 3 times during the treatment period.

RESULTS

Eleven females and 14 males participated, with a mean total burn surface area of 45% (SD = 23%) and mean age of 8 years (SD = 6). Imipramine was more effective than chloral hydrate in treating ASD symptoms (chi 2 [1, N = 25] = 5.24, p < .02). Five of 13 were positive responders to chloral hydrate (38%). Ten of 12 were positive responders to low-dose imipramine (83%).

CONCLUSIONS

This pilot study suggests a place for cautious initial use of imipramine to reduce ASD symptoms in burned children. Care must be taken to minimize cardiovascular risks in an off-label application of imipramine in children, especially those receiving additional medications.

An approach to the timely treatment of acute stress disorder

A convergent postburn psychopharmacologic treatment for children for acute stress disorder (ASD) symptoms has not been established. Both the application of what has been learned through treatment of similar symptoms experienced by adults with posttraumatic stress disorder and the examination of safe treatment options for children led to the clinical decision to use imipramine for 25 pediatric patients with acute burns. The treatment histories of these patients were retrospectively reviewed to see if further exploration into the efficacy of imipramine was warranted. Eighty percent of the children experienced remission of hyperarousal symptoms (eg, trouble staying asleep, trouble falling asleep) and intrusive reexperiencing symptoms (eg, nightmares). Twelve percent of the children experienced a decrease in the frequency or intensity of ASD symptoms. Eight percent had no relief of ASD symptoms. Initial findings suggest that imipramine assists children who have postburn ASD symptoms by decreasing the hyperarousal and intrusive reexperiencing symptoms of ASD.

Differential susceptibilities of Anopheles albimanus and Anopheles pseudopunctipennis to infections with coindigenous Plasmodium vivax variants VK210 and VK247 in southern Mexico

The susceptibilities to coindigenous Plasmodium vivax of colonized Anopheles albimanus and Anopheles pseudopunctipennis from southern Mexico were investigated by simultaneous feeding with infected blood obtained from patients. The genes encoding circumsporozoite protein variant types (VK210 and VK247) in blood samples were determined by PCR and oligonucleotide probe hybridization. A. albimanus was more susceptible to VK210, and A. pseudopunctipennis was more susceptible to VK247.

Colonization of Anopheles pseudopunctipennis from Mexico

Two colonies of Anopheles pseudopunctipennis, Tapachula and Abasolo strains, were established under laboratory conditions with a thermoperiod (29 degrees C during the day; 24 degrees C during the night) and artificial dusk. To stimulate mating, a light beam from a flashlight was shone on the cage shortly after lights off. This procedure was repeated for the first 6 mosquito generations (parental to F6) and thereafter light stimulation was unnecessary for mating. The Tapachula colony has been maintained for 24 generations in 24 months, with insemination rates in females > 80% since the F3, and a monthly production of 30,000 pupae since the F7. Using the same procedure, the Abasolo colony from northeastern Mexico has been maintained for 13 generations in 14 months, with insemination rates of 26-52%.

Ciprofloxacin as a therapeutic modality in pediatric burn wound infections: efficacious or contraindicated?

BACKGROUND

Food and Drug Administration regulations state that ciprofloxacin hydrochloride may cause arthropathies. For this reason, such therapy is contraindicated in the pediatric population. However, several studies in children with cystic fibrosis have found the drug to be efficacious. Our hypothesis was that ciprofloxacin treatment is justified in the case of multiresistant organisms in burn populations.

DESIGN

During a 4-year period (January 1, 1993, to December 31, 1997) we treated 56 of our pediatric burn patients with ciprofloxacin when cultures proved resistant to other antibiotics. The burn area was 65% of the total body surface area. The average patient age was 8.4 years. Of the 56 patients who received ciprofloxacin, 50 received the recommended dose. Biopsy specimens were assessed for quantitative bacteriology and antibiotic sensitivity. Radiologic review was conducted to examine for arthropathy.

RESULTS

All patients showed unequivocal reduction in quantitative bacterial counts, and susceptibility to ciprofloxacin remained stable without the development of resistance. Of the 56 patients treated, 42 had a major reduction in their quantitative wound biopsies from 10(6) to less than 100 colonies per gram of tissue, while the remaining 14 were observed to have a 2- to 3-log decrease. No arthropathy was detected in any of the 56 patients receiving ciprofloxacin. Review of the patients' charts showed no documented adverse events associated with the use of ciprofloxacin. All patients survived their thermal injury and the complications associated with it without any untoward problems or complications of arthropathy.

CONCLUSION

On the basis of these data, ciprofloxacin therapy in the treatment of immunosuppressed pediatric burn patients is efficacious and does not cause arthropathy.

Much ado about nothing: methicillin-resistant Staphylococcus aureus

The pathogenic methicillin-resistant Staphylococcus aureus (MRSA) has received a voluminous amount of notoriety. The four major reasons are its morbidity, mortality rate, cost of treatment, and constant appearance in intensive care units. Both Staphylococcus aureus and S. epidermidis (MRSE) account for 82% of our gram-positive wound isolates, whereas the gram-negative account for 34% of all isolates. Therefore we compared the morbidity, mortality rate, and cost factors related to MRSA-MRSE and gram-negative infections for a 4-year period, assessing more than 214 documented infections. Morbidity and mortality rates were minor for MRSA. Pseudomonas aeruginosa and Escherichia coli accounted for 57.5% of the total gram-negative isolates. Gram-negative antimicrobial therapy usually requires two therapeutic drugs, which increases morbidity and costs, whereas the staphylococci usually can be treated by one antimicrobial. During this period there were 47 gram-negative infections requiring 10 to 15 additional days of hospital stay, with a daily antibiotic cost of $293.40. Costs for MRSA or MRSE are 28% less. Therefore our preoccupation with MRSA or MRSE infections is unwarranted and unsubstantiated.

The use of aztreonam as an alternate therapy for multi-resistant Pseudomonas aeruginosa

The emergence of multi-resistant Gram-negative bacteria has created a most alarming clinical situation. The armamentarium of antibiotics used against this group of organisms is rapidly being depleted. Our routine therapeutic approach to control and prevent these Gram-negative bacteria from gaining a foothold was the empirical use of an aminoglycoside combined with piperacillin. However, aminoglycoside resistance is now routine rather than unusual. We evaluated the role of the monobactam aztreonam in burn wound infections and compared it to the aminoglycosides amikacin and gentamicin as well as piperacillin for the Enterobacteriacae and Pseudomonas aeruginosa. A total of 1274 Gram-negative isolates including P. aeruginosa were evaluated for susceptibility to the above-mentioned antibiotics from January 1995 to August 1995 (Table I). Among the Enterobacteriacae, aztreonam was more effective than amikacin and piperacillin (58.4 per cent vs. 45.8 per cent, respectively). However, it still fluctuated among the Enterobacteriacae as did the aminoglycosides. One major significant finding was that while susceptibility to aztreonam was variable for the Enterobacteriacae, P. aeruginosa remained 90 per cent susceptible to aztreonam and 90 per cent susceptible to piperacillin, whereas it was 79 per cent resistant to the aminoglycosides. Consequently, when choosing an antimicrobial in a suspected P. aeruginosa burn wound infection, aztreonam and piperacillin should be considered as the first line of defense.

Acetaminophen in the management of background pain in children post-burn

This retrospective review evaluated the pain management of 395 acutely burned pediatric patients who were treated by a pain management protocol emphasizing acetaminophen as the initial medication to control background pain. Pain was assessed by using standardized instruments based on observations by patients, nurses, and parents. Morphine was added when scheduled acetaminophen (10-15 mg/kg/4 hr) did not control background pain. Fifty percent of the children received only acetaminophen to control background pain. Younger children and children with the smallest burns, regardless of age, were likely to be managed with acetaminophen alone. Most peak serum concentrations of acetaminophen were less than 10 micrograms/mL. When needed, children also received medication for painful procedures, anxiety, and posttraumatic stress symptoms. These additional medications were not more frequently given to children receiving only acetaminophen for background pain. These data suggest that acetaminophen is a safe, useful medication for the control of post-burn background pain in some children.

Low-volume application by mist-blower compared with conventional compression sprayer treatment of houses with residual pyrethroid to control the malaria vector Anopheles albimanus in Mexico

Village-scale trials were carried out in southern Mexico to compare the efficacy of indoor-spraying of the pyrethroid insecticide lambda-cyhalothrin applied either as low-volume (LV) aqueous emulsion or as wettable-powder (WP) aqueous suspension for residual control of the principal coastal malaria vector Anopheles albimanus. Three indoor spray rounds were conducted at 3-month intervals using back-pack mist-blowers to apply lambda-cyhalothrin 12.5 mg a.i./m2 by LV, whereas the WP was applied by conventional compression sprayer at a mean rate of 26.5 mg a.i./m2. Both treatments caused mosquito mortality indoors and outdoors (collected inside house curtains) as a result of contact with treated surfaces before and after feeding, but had no significant impact on overall population density of An. albimanus resting indoors or assessed by human bait collections. Contact bioassays showed that WP and LV treatments with lambda-cyhalothrin were effective for 12-20 weeks (> 75% mortality) without causing excito-repellency. Compared to the WP treatment (8 houses/man/day), LV treatment (25 houses/man/day) was more than 3 times quicker per house, potentially saving 68% of labour costs. This is offset, however, by the much lower unit price of a compression sprayer (e.g. Hudson 'X-pert' at US$120) than a mist-blower (e.g. 'Super Jolly' at US$350), and higher running costs for LV applications. It was calculated, therefore, that LV becomes more economical than WP after 18.8 treatments/100 houses/10 men at equivalent rates of application, or after 7.6 spray rounds with half-rate LV applications.

Susceptibility of three laboratory strains of Anopheles albimanus (Diptera: Culicidae) to coindigenous Plasmodium vivax in southern Mexico

Three morphologically different pupal phenotypes (green, striped, brown) were selected from a parent strain of Anopheles albimanus Wiedemann collected from the Suchiate region in the state of Chiapas, Mexico. Significant differences in susceptibility to coindigenous Plasmodium vivax Grassi & Feletti were observed when striped was compared with the parent colony as well as with brown and with green phenotypes. Differences in susceptibility were not significant between the other phenotypes and the parent colony.

Low rates of multiple fertilization in parous Anopheles albimanus

We determined how frequently parous female Anopheles albimanus fertilize their eggs with sperm from more than one male. To establish paternity we relied on 2 phenotypically distinct laboratory strains. Nulliparous females were allowed to mate freely with males from one strain, and after oviposition they were offered a 2nd mating with males of the other strain. Fertilization patterns were determined by the phenotypes of offspring. Only 0.6% of females ovipositing for a 2nd time (n = 312) used sperm from the 2nd male, as did 4% of females completing a 3rd gonotrophic cycle (n = 25). In this species receptivity is not routinely renewed following oviposition.

[Effectiveness of a carbamate insecticide as a household low-volume spray for malaria control]

A comparative regional-scale evaluation of the epidemiological impact of low volume (LV) spray of bendiocarb and the conventional spray of DDT against malaria in an endemic area of northern Chiapas was carried out. Three Anopheline species were found: Anopheles pseudopunctipennis, An. albinanus and An. argyritarsis. The most prevalent was An. pseudopunctipennis, a species we suspect may be involved in the transmission of most malaria cases. This species showed high levels of resistance to DDT. However, this insecticide had a long residual effect in wall bioassays, with mortalities > or = 95 per cent for up to 21 weeks in wood, sticks and plaster. Susceptibility to bendiocarb was total, and mortality to LV bendiocarb was > or = 75 per cent for up to 16 weeks in wood, sticks and straw. Very low numbers of mosquitoes were found throughout the evaluation, although malaria transmission continued in control villages (sprayed with DDT), as well as treated villages (sprayed with LV bendiocarb). No plasmodium infected mosquitoes were found, perhaps due to a very small sample size. The LV spray methodology was found to be 1.7 times more effective than conventional spraying in reducing malaria incidence. A net reduction of 1.6 times in insecticide application time was also found, which would allow spraying at the right time, especially when urgent control measures have to be applied, such as in malaria outbreaks. Finally, the new methodology costs 2.2 times more than the conventional ddt spraying, but if the potential of using spray workers in other activities is considered, costs would be comparable to those of DDT spraying.