10 research outputs found
On the origins of American Criollo pigs: A common genetic background with a lasting Iberian signature
American Criollo pigs are thought to descend mainly from those imported from the Iberian Peninsula starting in the late 15th century. Criollo pigs subsequently expanded throughout the Americas, adapting to very diverse environments, and possibly receiving influences from other origins. With the intensification of agriculture in the mid-20th century, cosmopolitan breeds largely replaced Criollo pigs, and the few remaining are mostly maintained by rural communities in marginal areas where they still play an important socio-economic and cultural role. In this study, we used 24 microsatellite markers in samples from 1715 pigs representing 46 breeds with worldwide distribution, including 17 American Criollo breeds, with the major focus of investigating their genetic diversity, structure and breed relationships. We also included representatives of the Iberian, Local British, Hungarian, Chinese and Commercial breeds, as well as Wild Boar, in order to investigate their possible influence in the genetic composition of Criollos. Our results show that, when compared with the other breeds, Criollo pigs present higher levels of genetic diversity, both in terms of allelic diversity and expected heterozygosity. The various analyses indicate that breed differentiation overall explains nearly 21% of the total genetic diversity. Criollo breeds showed their own identity and shared a common genetic background, tending to cluster together in various analyses, even though they differ from each other. A close relationship of Criollos with Iberian breeds was revealed by all the different analyses, and the contribution of Iberian breeds, particularly of the Celtic breeds, is still present in various Criollo breeds. No influence of Chinese breeds was detected on Criollos, but a few were influenced by Commercial breeds or by wild pigs. Our results confirm the uniqueness of American Criollo pigs and the role that Iberian breeds have played in their development. © 2021 Revidatti et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Environmental straits of Cryptococcus neoformans variety grubii in the city of Santos, SP, Brazil Amostras ambientais de Cryptococcus neoformans var. grubii na cidade de Santos, SP, Brasil
This study involved a total of 116 samples, 79 taken from pigeon droppings and 37 of atmospheric air taken close to accumulations of excrement. Cryptococcus neoformans var. grubii was isolated from 11 (13.9%) of these samples. Other species of Cryptococcus were also isolated from these samples, such as C. albidus (12.6%) and C. laurentii (8.9%). C. neoformans was not isolated from the air samples, though C. albidus (5.4%) was. All the strains of C. neoformans were found to belong to the A serotype (C. neoformans var. grubii). In regard to the studies with the antifungal agents 5-fluorocytosine, fluconazole, itraconazole, amphotericin B and voriconazole, by means of the microdilution method (EUCAST), we point out that one sample demonstrated resistance to fluconazole, this being especially significant because this is an environmental strain.<br>Analisaram-se 116 amostras, sendo 79 de fezes de pombos e 37 de ar atmosfĂ©rico de regiĂ”es com acĂșmulo de fezes. Isolou-se Cryptococcus neoformans var. neoformans de 11 (13.9%) destas amostras. Outras espĂ©cies de Cryptococcus tambĂ©m foram isoladas destas amostras tais como C. laurentii (8.9%) e C. albidus (12.6 %), o qual tambĂ©m foi isolado de amostras do ar (5.4 %). Todas as amostras de C. neoformans foram sorotipo A (C. neoformans var. grubii). Em relação Ă avaliação do perfil de sensibilidade Ă s drogas antifĂșngicas (5-fluorocitosina, fluconazol, itraconazol, anfotericina B e voriconazol) pelo mĂ©todo da microdiluição (EUCAST, 2002), destacou-se a presença de uma amostra com valor de concentração inibitĂłria mĂnima (CIM) elevado para fluconazol, sendo de grande significĂąncia, uma vez tratar-se de isolado ambiental
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
Aim
Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.
Location
Amazonia.
Taxon
Angiosperms (Magnoliids; Monocots; Eudicots).
Methods
Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.
Results
In the terra firme and vĂĄrzea forest types, the phylogenetic composition varies by geographic region, but the igapĂł and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2â=â19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2â=â28%). A greater number of lineages were significant indicators of geographic regions than forest types.
Main Conclusion
Numerous tree lineages, including some ancient ones (>66âMa), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications
Background:
The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.
Methods:
ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.
Results:
The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.
Conclusions:
This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.
© 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran
Diminishing benefits of urban living for children and adolescentsâ growth and development
Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1â6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5â19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was &lt;1.1 kg mâ2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified. © 2023, The Author(s)