Chemical signals act as the main reproductive barrier between sister and mimetic Heliconius butterflies.

Colour pattern is the main trait that drives mate recognition between Heliconius species that are phylogenetically close. However, when this cue is compromised such as in cases of mimetic, sympatric and closely related species, alternative mating signals must evolve to ensure reproductive isolation and species integrity. The closely related species Heliconius melpomene malleti and H. timareta florencia occur in the same geographical region, and despite being co-mimics, they display strong reproductive isolation. In order to test which cues differ between species, and potentially contribute to reproductive isolation, we quantified differences in the wing phenotype and the male chemical profile. As expected, the wing colour pattern was indistinguishable between the two species, while the chemical profile of the androconial and genital males' extracts showed marked differences. We then conducted behavioural experiments to study the importance of these signals in mate recognition by females. In agreement with our previous results, we found that chemical blends and not wing colour pattern drive the preference of females for conspecific males. Also, experiments with hybrid males and females suggested an important genetic component for both chemical production and preference. Altogether, these results suggest that chemicals are the major reproductive barrier opposing gene flow between these two sister and co-mimic species.

Deforestation in Colombian protected areas increased during post-conflict periods.

Protected areas (PAs) are a foundational and essential strategy for reducing biodiversity loss. However, many PAs around the world exist on paper only; thus, while logging and habitat conversion may be banned in these areas, illegal activities often continue to cause alarming habitat destruction. In such cases, the presence of armed conflict may ultimately prevent incursions to a greater extent than the absence of conflict. Although there are several reports of habitat destruction following cessation of conflict, there has never been a systematic and quantitative "before-and-after-conflict" analysis of a large sample of PAs and surrounding areas. Here we report the results of such a study in Colombia, using an open-access global forest change dataset. By analysing 39 PAs over three years before and after Colombia's peace agreement with the Revolutionary Armed Forces of Colombia (FARC), we found a dramatic and highly significant increase in the deforestation rate for the majority of these areas and their buffer zones. We discuss the reasons behind such findings from the Colombian case, and debate some general conservation lessons applicable to other countries undergoing post-conflict transitions.

Five-year follow-up of immune response after one or two doses of inactivated hepatitis A vaccine given at 1 year of age in the Mendoza Province of Argentina.

Our study was conducted to further investigate the single-dose approach of hepatitis A vaccination, while providing supportive data on the flexibility of booster administration. Participants received at least one dose of Avaxim 80U Pediatric at 11-23 months of age, and they will be followed for 10 years. We report here the fourth and fifth years after the first vaccination. Group assignment was based on whether the children received 1 dose and no booster during the study (Group 1) or 2 doses and no further booster (Group 2). Anti-HAV antibody concentrations were assessed at each annual visit. Of the 546 initial participants, 441 (80.8%) and 412 (75.5%) were followed up 4 and 5 years after vaccination, respectively. Of the 411 subjects evaluable at Year 5, 318 had received one vaccine dose and 85 had received two. Seroprotection rates were still high in Group 1 (99.7%) and in Group 2 (100%) 5 years after one or two doses of Avaxim 80U Pediatric, correspondingly. Anti-HAV geometric mean concentrations decreased in both groups compared to what they were 3 years after vaccination, while remaining well above the 10 mIU/mL threshold 5 years after vaccination. The highest concentrations were found in the children who received 2 vaccine doses. Hepatitis A humoral immunity induced by a single dose of inactivated hepatitis A vaccine can persist for at least 5 years in a paediatric population. The study results also support recommendations in favour of a flexible time window for booster vaccination.

Efecto biológico de la hipertermia hídrica controlada sobre hueso sano de conejos / Biological effect of controlled fluid hyperthermia on rabbit healthy bones

La hipertermia hídrica se ha utilizado para tratamientos de diversas formas de cáncer, en hueso aún no se ha determinado cuál es su efecto; se realizó este estudio prospectivo para demostrar los cambios estructurales y metabólicos y los efectos en la consolidación de hueso expuesto a hipertermia hídrica. Se utilizaron 30 conejos de raza New-Zealand. Con peso entre 2.8 y 3.2 kg divididos en 9 grupos y 3 subgrupos, se realizó osteotomía en el tercio medio del fémur derecho; este segmento fue expuesto a hipertermia a 15, 20 y 25 grados centígrados, durante 50, 60 y 70 minutos, gammagrafía ósea cada cuatro semanas y radiográficos cada semana hasta la semana 13. Para el análisis estadístico se utilizó la prueba de post-hoc y test de Tukey, encontrando diferencias en las concentraciones de elementos químicos a temperaturas superiores a 60 grados durante 20 minutos con significancia estadística, retardo en la consolidación y evidencia de actividad metabólica. Se concluye que con la exposición a temperaturas de 60 grados durante 20 minutos se presentaron alteraciones morfológicas en potasio, magnesio, azufre y fósforo y retardo en la consolidación ósea. Estos resultados son usados como parámetros para el tratamiento con hipertermia hídrica controlada en tumores óseos.

Fluid hyperthermia has been used to treat various types of cancers, but its effects on bone have not been determined. The purpose of this prospective study was to show the structural and metabolic changes of bone exposed to fluid hyperthermia and the effects of the latter on bone healing. Thirty New Zealand rabbits were used, weighting 2.8-3.2 kg; they were divided into 9 groups and 3 subgroups. An osteotomy was performed in the mid third of the right femur and this segment was exposed to hyperthermia at 15, 20 and 25 degrees centigrade for 50, 60 and 70 minutes. A bone scan was performed every 4 weeks and X-rays were taken every week up to week 13. The post-hoc Tukey test was used for the statistical analysis. Differences were found in the concentration of chemicals at temperatures above 60 degrees for 20 minutes with statistical significance; bone healing was delayed and there was evidence of metabolic activity. We conclude that exposure to temperatures above 60 degrees for 20 minutes resulted in morphologic alterations in potassium, magnesium, sulfur and phosphorus, and delayed bone healing. These results are used as parameters for the treatment of bone tumors with fluid hyperthermia.

[Biological effect of controlled fluid hyperthermia on rabbit healthy bones]. / Efecto biológico de la hipertermia hídrica controlada sobre hueso sano de Conejos.

Fluid hyperthermia has been used to treat various types of cancers, but its effects on bone have not been determined. The purpose of this prospective study was to show the structural and metabolic changes of bone exposed to fluid hyperthermia and the effects of the latter on bone healing. Thirty New Zealand rabbits were used, weighting 2.8-3.2 kg; they were divided into 9 groups and 3 subgroups. An osteotomy was performed in the mid third of the right femur and this segment was exposed to hyperthermia at 15, 20 and 25 degrees centigrade for 50, 60 and 70 minutes. A bone scan was performed every 4 weeks and X-rays were taken every week up to week 13. The post-hoc Tukey test was used for the statistical analysis. Differences were found in the concentration of chemicals at temperatures above 60 degrees for 20 minutes with statistical significance; bone healing was delayed and there was evidence of metabolic activity. We conclude that exposure to temperatures above 60 degrees for 20 minutes resulted in morphologic alterations in potassium, magnesium, sulfur and phosphorus, and delayed bone healing. These results are used as parameters for the treatment of bone tumors with fluid hyperthermia.

Multiple sources of reproductive isolation in a bimodal butterfly hybrid zone.

An important evolutionary question concerns whether one or many barriers are involved in the early stages of speciation. We examine pre- and post-zygotic reproductive barriers between two species of butterflies (Heliconius erato chestertonii and H. e. venus) separated by a bimodal hybrid zone in the Cauca Valley, Colombia. We show that there is both strong pre- and post-mating reproductive isolation, together leading to a 98% reduction in gene flow between the species. Pre-mating isolation plays a primary role, contributing strongly to this isolation (87%), similar to previous examples in Heliconius. Post-mating isolation was also strong, with absence of Haldane's rule, but an asymmetric reduction in fertility (< 11%) in inter-specific crosses depending on maternal genotype. In summary, this is one of the first examples of post-zygotic reproductive isolation playing a significant role in early stages of parapatric speciation in Heliconius and demonstrates the importance of multiple barriers to gene flow in the speciation process.

Hybrid incompatibility is consistent with a hybrid origin of Heliconius heurippa Hewitson from its close relatives, Heliconius cydno Doubleday and Heliconius melpomene Linnaeus.

Abstract Shared ancestral variation and introgression complicates the reconstruction of phylogenetic relationships among closely related taxa. Here we use overall genomic compatibility as an alternative estimate of species relationships in a group where divergence is rapid and genetic exchange is common. Heliconius heurippa, a butterfly species endemic to Colombia, has a colour pattern genetically intermediate between H. cydno and H. melpomene: its hindwing is nearly indistinguishable from that of H. melpomene and its forewing band is an intermediate phenotype between both species. This observation has lead to the suggestion that the pattern of H. heurippa arose through hybridization. We present a genetic analysis of hybrid compatibility in crosses between the three taxa. Heliconius heurippa x H. cydno and female H. melpomene x male H. heurippa yield fertile and viable F1 hybrids, but male H. melpomene x female H. heurippa crosses yield sterile F1 females. In contrast, Haldane's rule has previously been detected between H. melpomene and H cydno in both directions. Therefore, H. heurippa is most closely related to H. cydno, with some evidence for introgression of genes from H. melpomene. The results are compatible with the hypothesis of a hybrid origin for H. heurippa. In addition, backcrosses using F1 hybrid males provide evidence for a large Z(X)-chromosome effect on sterility and for recessive autosomal sterility factors as predicted by Dominance Theory.

Effects of different thermal treatments and storage on the proximate composition and protein quality in canned tuna.

The purpose of this project was to study the modifications in nutrient composition, amino acid content, and protein quality of white tuna preserves after each of the thermal treatments involved in the canning process. Also the influence that a three years storage period at room temperature has on the nutritional quality of canned tuna was studied. The biological assays used for the study of the protein utilization were carried out on Wistar rats, fed on semi-synthetic diets for 12 days varying only the protein source, casein or tuna provided as follows: raw, cooked in brine, steamed, sterilized tuna, and canned tuna stored for three years. The sterilization process and storage time led to a great increase in the lipid content of the canned tuna and to a porcentual decrease in protein, and moisture content. Amino acid composition of canned and cooked tuna did not show great modifications compared to raw tuna. Neither protein digestibility nor biological value of the cooked, canned, and stored tuna showed any deterioration. The protein quality of white tuna meat preserves has been compared with preserves made up of red and white tuna meat.

Historical demography of Mullerian mimicry in the neotropical Heliconius butterflies.

We compare the historical demographies of two Müllerian comimetic butterfly species: Heliconius erato and Heliconius melpomene. These species show an extensive parallel geographic divergence in their aposematic wing phenotypes. Recent studies suggest that this coincident mosaic results from simultaneous demographic processes shaped by extrinsic forces over Pleistocene climate fluctuations. However, DNA sequence variation at two rapidly evolving unlinked nuclear loci, Mannose phosphate isomerase (Mpi) and Triose phosphate isomerase (Tpi), show that the comimetic species have quite different quaternary demographies. In H. erato, despite ongoing lineage sorting across the Andes, nuclear genealogical estimates showed little geographical structure, suggesting high historical gene flow. Coalescent-based demographic analysis revealed population growth since the Pliocene period. Although these patterns suggest vicariant population subdivision associated with the Andean orogeny, they are not consistent with hypotheses of Pleistocene population fragmentation facilitating allopatric wing phenotype radiation in H. erato. In contrast, nuclear genetic diversity, theta, in H. melpomene was reduced relative to its comimic and revealed three phylogeographical clades. The pattern of coalescent events within regional clades was most consistent with population growth in relatively isolated populations after a recent period of restricted population size. These different demographic histories suggest that the wing-pattern radiations were not coincident in the two species. Instead, larger effective population size (N(e)) in H. erato, together with profound population change in H. melpomene, supports an earlier hypothesis that H. erato diversified first as the model species of this remarkable mimetic association.

Effects of different thermal treatments and storage on the proximate composition and protein quality in canned tuna

El objetivo de este trabajo fue estudiar las modificaciones en el contenido en nutrientes, aminoácidos y la calidad proteínica de conservas de atún blanco después de cada uno de los tratamientos térmicos incluidos en el proceso de enlatado. Así como estudiar la influencia que el almacenamiento durante tres años a temperatura ambiente ejerce sobre la calidad nutricional del atún en lata. Los ensayos biológicos empleados para estudiar la utilización proteínica se llevaron a cabo con ratas Wistar, alimentadas con dietas semisintéticas durante 12 días variando solamente la fuente proteínica, caseína o atún, proporcionado de la siguiente manera: crudo, cocinado en salmuera, cocinado al vapor, esterilizado y enlatado almacenado durante tres años. El proceso de esterilización y el tiempo de almacenamiento producen un incremento en el contenido de lípidos del atún enlatado y un descenso porcentual en el contenido de proteína y humedad. El perfil aminoacídico del atún enlatado y cocinado no mostró grandes modificaciones comparado con el atún crudo. Ni la digestibilidad proteínica ni el valor biológico del atún cocinado, enlatado y almacenado mostró ninguna alteración. La calidad proteínica de las conservas de carne blanca de atún fue comparada con la calidad proteínica de las conservas elaboradas con carne roja y blanca de atún

Effects of hydroxypropyl-beta-cyclodextrin on the chemical stability of a naphthoquinone in aqueous solutions.

2-Hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1,4-naphthoquinone-4-imine (1), an antibacterial agent, was shown to form inclusion complexes with HP-beta-CD in aqueous solution. In the present work the kinetics of 1 degradation in aqueous buffer solution was investigated as a function of pH (2.34-3.95), HP-beta-CD concentration (0%-28% (w/v)) and temperature (60-90 degrees C). A second-order derivative spectroscopic methodology was developed for the kinetic investigations. The degradation showed to follow pseudo-first-order kinetics. Also, an specific acid catalysis was found and the introduction of up to 28% (w/v) HP-beta-CD to the reaction medium did not change this kinetic behaviour. The obtained results indicated that HP-beta-CD stabilises 1 against degradation in aqueous solutions.

Influencia de la infección por VIH/SIDA sobre indicadores antropométricos del estado nutricional / HIV-AIDS infection influence on anthropometric indicators of nutritional state

Analisa a influência da infecção pelo HIV e o estágio clínico da doença sobre diferentes indicadores antropométricos do estado nutricional do indivíduo

[Influence of HIV/AIDS infection on some biochemical indicators of the nutritional status]. / Influencia de la infección por VIH/SIDA sobre algunos indicadores bioquímicos del estado nutricional.

The main objective of this study was to analyze the influence of nutritional state among HIV-1 infected people, according to the different clinical stages referred by the CDC (Control Disease Center of the United States) in 1987, as well as the changes in the concentrations of some biochemical markers linked to nutritional state. A similar study was carried out in a control group with UltramicroELISA non-reagent healthy individuals, anthropometrically classified. Concentrations of total proteins, albumin, cholesterol, triglycerides, urea, uric acid and creatinine were analyzed by sex and clinical group, comparing the levels obtained through a variance study. When comparing HIV-1 asymptomatic infected patients to HIV-1 and HIV-2 non infected people, the results showed a non significant increase in the level of total proteins with a significant decrease of albumin and creatinine, the latter observed only in male patients. In stage IV patients, an important decrease of cholesterol and a significant increase of the triglycerides were found, as well as the lowest albumin levels. Urea and uric acid levels did not experience statistically significant changes. It was concluded that the study of biochemical markers is advisable, since it contributes to the detection by default of malnutrition marginal states in infected individuals.

Influencia de la infección por VIH/sida sobre algunos indicadores bioquímicos del estado nutricional / influence of HIV/AIDS infection on some nutritional state biochemical markers

Con el objetivo de analizar la influencia de la infección por el VIH y el estadio clínico de la enfermedad sobre indicadores bioquímicos del estado nutricional del individuo, se estudió un grupo de individuos infectados y clasificados en diferentes grupos clínicos, de acuerdo con los criterios propuestos en 1987 por el Centro de Control de Enfermedades de los Estados Unidos, así como un grupo control integrado por sujetos seronegativos al VIH y clasificados antropométricamente con un estado nutricional normal. Se analizaron las variaciones experimentadas por las proteínas totales, albúmina, colesterol, triacilglicéridos, urea, ácido úrico y creatinina, según sexo y grupo clínico, para lo cual se realizó la comparación de las medias obtenidas por medio de un análisis de la varianza. Al compararlos con los seronegativos, se encontró en los seropositivos asintomáticos un incremento no significativo de las proteínas totales con disminusión significativa de la albúmina y la creatinina; esta última sólo en el sexo masculino. En los pacientes del estadio IV se manifestó la disminución más importante del colesterol y un aumento significativo de los triglicéridos, así como los niveles más bajos de albúmina. La urea y el ácido úrico no experimentaron cambios con significación estadística. Se recomienda la determinación de indicadores bioquímicos en la detección de estados marginales de malnutrición por defecto en individuos VIH/SIDA

Effect of hydroxypropyl-beta-cyclodextrin on the solubility of an antibacterial isoxazolyl-naphthoquinone.

The complexation of 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1,4-naphthoquinone-4-imine (I) with a highly soluble cyclodextrin, hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was studied in aqueous media by solubility methods. I is an antibacterial and trypanocidal agent that is undergoing preclinical testing. Unfortunately, I exhibits low water solubility, and it is therefore difficult to prepare the solutions for biological tests. I inclusion took place with 1:1 stoichiometry. The stability constants of the I complexes calculated from the slope and the intercept of the phase solubility diagrams are larger in the less ionized form, whereas greater overall solubility is obtained in basic media.

[Monoclonal antibodies in the treatment of sepsis caused by Gram-negative microorganisms]. / Los anticuerpos monoclonales en el tratamiento de la sepsis provocada por microorganismos gramnegativos.

In spite of the advances attained in the diagnosis and early intervention with antibiotics, morbidity and mortality associated with sepsis caused by Gram-negative bacteria are high. The mediators responsible for the pathogenesis of the sepsis are components derived from the own bacteria (endotoxins) and from the cells of the immune response of the host (tumor necrosis factor and some interleukins). The treatment traditionally used in sepsis is mainly directed against microorganisms by the use of increasingly potent antibiotics. However, it is clear that antibiotics are not a definitive solution, since even when they cause bacterial death, they have no effects on endotoxin and may increase their liberation when cellular lysis occurs. New and successful treatments for sepsis have been tried since the 1980's, including the use of polyclonal and monoclonal antibodies of murine and human origin, directed against the lipid A of the endotoxin, as well as monoclonal antibodies against the tumor necrosis factor. Although these molecules are not completely efficient for the interruption of the chain of undesirable events provoked by the endotoxin, it is valid to accept the appearance of immunotherapies as an adjuvant treatment for a condition that threatens life.

Etiology of bloody diarrhea in Bolivian children: implications for empiric therapy. Bolivian Dysentery Study Group.

In Bolivia, few data are available to guide empiric therapy for bloody diarrhea. A study was conducted between December 1994 and April 1995 to identify organisms causing bloody diarrhea in Bolivian children. Rectal swabs from children <5 years old with bloody diarrhea were examined for Salmonella, Shigella, and Campylobacter organisms; fecal specimens were examined for Entamoeba histolytica. A bacterial pathogen was identified in specimens from 55 patients (41%). Shigella organisms were found in 39 specimens (29%); 37 isolates (95%) were resistant to ampicillin, 35 (90%) to trimethoprim-sulfamethoxazole, and 24 (62%) to chloramphenicol, but all were susceptible to nalidixic acid. Only 1 of 133 stool specimens contained E. histolytica trophozoites. Multidrug-resistant Shigella species are a frequent cause of bloody diarrhea in Bolivian children; E. histolytica is uncommon. Clinical predictors described in this study may help identify patients most likely to have Shigella infection. Laboratory surveillance is essential to monitor antimicrobial resistance and guide empiric treatment.