Biochemical characterization and mycorrhizal fungal community of plant species in the Brazilian seasonal dry forest.

Invasive alien plant species (IAPS) have the ability to change the biochemical properties and the arbuscular mycorrhizal fungal (AMF) community structure in their rhizosphere. Organic acids, microbial activity, and AMF play a key role in the invader's spread and also has interactions with the soil chemical factors. Our aim here was to assess the rhizosphere's biochemical factors, AMF community composition, and soil chemical properties associated with Cryptostegia madagascariensis (IAPS) and Mimosa tenuiflora (endemic plant species) from the Brazilian Seasonal Dry Forest. The highest values of total glomalin (5.87 mg g-1 soil), root colonization (54.5%), oxalic and malic acids (84.21 and 3.01 µmol g-1 , respectively), microbial biomass C (mg kg-1 ), Na+ (0.080 cmolc kg-1 ), Ca2+ (7.04 cmolc kg-1 ), and soil organic carbon (4.59 g kg-1 ) were found in the rhizosphere of C. madagascariensis. We found dissimilarities on AMF community structure considering the studied plant species: (i) Racocetra coralloidea, Dentiscutata heterogama, Dentiscutata cerradensis, Gigaspora decipiens, and AMF's richness were highly correlated with the rhizosphere of M. tenuiflora; and (ii). The rhizosphere of C. madagascariensis was highly correlated with the abundance of Claroideoglomus etunicatum, Rhizoglomus aggregatum, Funneliformis mosseae, and Funneliformis geosporum. The results of our study highlight the importance of considering C. madagascariensis as potential hosts for AMF species from Glomerales, and a potential plant species that increase the bioavailability of exchangeable Na and Ca at semi-arid conditions.

Comparative Study of Egg and Meat Quality of Guinea Fowl under Different tropical regions: A Review

Guinea fowl have several advantages over chickens. These birds are highly valued for their meat and eggs, particularly in tropical regions. They are currently in many parts of the world. Recently, the demand for guinea fowl meat has increased because it is considered a high-quality protein source. In addition, their eggs are delicious and considerably better than those of chickens. Guinea fowl eggs are valued for their thick shells, and longer shelf life, and it has premium prices compared with commercial and indigenous chickens. Chicken eggs have been well studied for egg and meat quality. However, such information isn't so sufficiently documented in other poultry species. Despite the interest in guinea fowl production, it is vital to take cognizance of the fact that there is a lack of information on the production and quality of guinea fowl products, in contrast to commercial chickens. Therefore, the present review aims to assess the egg and meat quality of Guinea fowl in different tropical regions. The main results of the current study showed that the external egg quality characteristics, mainly (egg weight, shell percentage, and shell thickness), and internal egg quality traits, mainly (albumen weight, haugh unit, yolk height, and yolk color) of Guinea fowl differed under different tropical regions. Concerning carcass characteristics, a clear difference was observed in dressing percentage and breast percentage of Guinea fowl in various tropical areas. A similar trend was observed for the meat color.(AU)

Bibliometrics of Cambodian Science: subjects, researchers and impact in the Science Citation Index Expanded / Bibliometría de la ciencia camboyana: temas, investigadores e impacto en el Science Citation Index Expanded

Abstract Introduction: Cambodia is a small agricultural tropical country for which only two small scientometric studies, published five years ago, were available until now. Objective: To identify, for Cambodian research, subjects, outlets, authors, institutions, citations and recommendations. Methods: The data were retrieved from the Science Citation Index Expanded (January 04, 2021) using the word "Cambodia" for the period 1972 to 2019. Results: We retrieved 3 689 documents: for the half century covered, the yearly presence of Cambodia in the index has grown strongly, to 325 articles and 6 555 authors in 2019 alone. Most documents are articles in English about health, particularly infectious and tropical diseases. Most international collaboration is done, by country, with the USA, France, and Thailand; and by institution, with Mahidol University, the Pasteur Institute and Oxford University. The most productive institutions are the Cambodian Ministry of Health and the Cambodian National Center for Parasitology. The main outlets are PLoS One, Malaria and PLoS Neglected Tropical Diseases. Cambodian articles are cited for up to 33 years, with a peak of 4.5 citations within the first two years. Those in English, or from well-funded foreign projects, have more citations in this particular index; especially if they are about malaria, hepatitis or influenza. Conclusions: The nature and impact of Cambodian science outside the SCI-EXPANDED remain unknown, but publications in that index have increased, concentrate on solving local problems, and depend heavily on international collaboration, following a well-known pattern of science in tropical countries. We suggest a funding system based on international peers who assign funds to the most productive researchers with minimal bureaucracy, so that local research is done on a greater variety of topics and with less participation of Cambodian researchers as low-level members in foreign projects.

Resumen Introducción: Camboya es un país tropical asiático pequeño y "subdesarrollado", con una economía basada en la agricultura, para el que hasta ahora solo estaban disponibles dos pequeños estudios cienciométricos, publicados hace cinco años. Objetivo: Identificar, para la investigación camboyana, qué se estudia; quién hizo la investigación; dónde y cuándo se publicó; y los factores que afectan su citación. Métodos: Usamos el Science Citation Index Expanded (4 de enero de 2021) utilizando la palabra "Camboya" y se limitaron al período 1972 a 2019. Resultados: Hallamos 3 689 documentos; durante el medio siglo cubierto, la presencia anual de Camboya en el índice ha aumentado considerablemente, con 325 artículos y 6 555 autores incorporados tan solo en 2019. La mayoría son artículos en inglés sobre salud, particularmente enfermedades infecciosas y tropicales. La mayor parte de la colaboración internacional se realiza, por país, con EE. UU., Francia y Tailandia; y por institución, con la Universidad Mahidol, el Instituto Pasteur y la Universidad de Oxford. Las instituciones más productivas son el Ministerio de Salud de Camboya y el Centro Nacional de Parasitología de Camboya. Las principales revistas son PLoS One, Malaria y PLoS Neglected Tropical Diseases. Los artículos camboyanos se citan hasta por 33 años, con un máximo de 4.5 citas en los dos primeros años. Los que son en inglés, o de proyectos dirigidos por el extranjero, tienen más citas en esta base de datos; particularmente si se trata de malaria, hepatitis o influenza. Conclusiones: La naturaleza y el impacto de la ciencia camboyana fuera del SCI-EXPANDED siguen sin conocerse, pero las publicaciones en ese índice han aumentado, se concentran en resolver problemas locales y dependen en gran medida de la colaboración internacional, siguiendo un patrón bien conocido en los países tropicales. Sugerimos un sistema de financiación basado en pares internacionales que asignen, con burocracia mínima, fondos a los investigadores más productivos, de modo que la investigación local se realice en una mayor variedad de temas y con una menor participación de investigadores camboyanos como miembros de bajo nivel en proyectos extranjeros.

Hygienic conditions influence sensitization to Blomia tropicalis allergenic components: Results from the FRAAT birth cohort.

BACKGROUND: In tropical zones, perennial exposure to house dust mite (HDM) allergens and helminth infections is present. Studying the impact of these conditions on the inception and evolution of allergic diseases is necessary to have an accurate view of their natural history. We aimed to evaluate the dynamics of genuine sensitization to Blomia tropicalis and Ascaris in children from the FRAAT birth cohort and the effects of helminth infection, environmental HDM allergen levels, and sociodemographic factors. METHODS: Children were followed up to 6 years old. Specific IgE to recombinant allergens from B. tropicalis (Blo t 5 and Blo t 12) and Ascaris spp (Asc l 3, Asc l 13 and Asc s 1) was measured by ELISA at different time points. Allergen levels were measured in dust when children were 6 months old. RESULTS: IgE sensitization increased over time up to 3 years old. Correlation among the specific IgE levels to B. tropicalis and Ascaris components is poor at year 1, but coefficients are high and significant (Spearman's rho coefficients >0.70) at year 6. Unhygienic conditions increased the odds of sensitization to B. tropicalis allergenic components. Blo t 5 levels were lower in the poorest. IgE response to Blo t 5 and Blo t 12 was less intense in children with high exposure to Blo t 5 (levels >80th percentile). CONCLUSION: In this tropical community, the pattern of childhood IgE sensitization is different from that in developing countries and is influenced by the hygienic conditions.

The tropics, helminth infections and hygiene hypotheses.

The Tropics is very appropriate to test the hypotheses raised to explain the increasing trends of allergy and other inflammatory diseases worldwide. The absence of parasite infection as a possible cause of the increase of allergic diseases was proposed by J. Gerrard a long time ago; however, the idea that helminth infections, which induce a strong Th2 could reduce allergy symptoms seems counterintuitive; but the fact is that they have a dual effect: they increase the Th2 responses but also exert immunosuppression and both effects influence the symptoms of allergy. Basic experimentation has provided valuable information about the mechanisms of allergic inflammation and more recently, about its control by helminth induced immunomodulation, discovering helminth molecules with anti-inflammatory properties that are meant to replace the live helminth therapeutic approaches. The immunosuppressive power of helminths makes them excellent candidates to be considered in the hygiene hypotheses. Future comprehensive studies evaluating simultaneously the role of microbial infections, helminth infections, microbiota, pollution and biodiversity will help to elucidate the causes of the increasing trends of allergic disorders. Doing this in the tropics, where all these variables are still present could be difficult but no doubt that will be more informative.

Particularities of allergy in the Tropics.

Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

The IgE response to Ascaris molecular components is associated with clinical indicators of asthma severity.

BACKGROUND: Asthma is a common chronic disease worldwide and Ascaris lumbricoides infection (ascariasis) is frequent in tropical regions. However, the effect of ascariasis on asthma severity has not been sufficiently explored. We sought to evaluate the influence of the IgE immune response to Ascaris extract and purified house dust mites (HDM) and Ascaris allergens on indicators of asthma severity in patients living in the tropics. METHODS: Asthmatic patients from Cartagena, Colombia were recruited. Clinical assessment included questionnaires, physical examination, allergy skin tests, spirometry, parasite stool examination and IgE antibody measurements. Asthma was diagnosed by a physician according to validated criteria. Indicators of severity were occurrence of severe dyspnea episodes, night awakenings events, > 4 emergency room (ER) visits and hospitalizations during the last year. Specific IgE to Der p 2, Ascaris spp., Blomia tropicalis and Dermatophagoides pteronyssinus extracts was determined by ImmunoCap. IgE to tropomyosins (Asc l 3, Blo t 10 and Der p 10), Blo t 5 and Asc s 1 was detected by ELISA. Logistic regression analyses were used to explore the relationships between sensitization and indicators of asthma severity. RESULTS: After adjustment for HDM sensitization, Ascaris sensitization remained associated with severe dyspnea (aOR: 1.90, 95% CI: 1.08 - 3.34, p = 0.03) and > 4 ER visits (aOR: 2.23, 95% CI: 1.15 - 4.30, p = 0.02). We also found that sensitization to the species specific markers Blo t 5 and Asc s 1, as well as the cross-reactive tropomyosins of D. pteronyssinus and Ascaris were associated with > 4 ER visits. Der p 2 sensitization was associated with bronchodilator responsiveness (aOR: 2.24: 1.25-4.02, p = 0.01). Remarkably, significantly higher IgE levels to HDM species specific allergens were found in Ascaris sensitized patients. CONCLUSIONS: In this tropical population, IgE sensitization to Ascaris and the cross-reactive tropomyosins was frequent and associated with clinical indicators of asthma severity. The significant relationship between sensitization to the nematode-specific marker Asc s 1 and ER attendance supports these findings. Moreover, ascariasis increases the human IgE responses to HDM specific allergens.