Cosecha: A Statewide Promotor de Salud Network to Attain Equity in Accessing COVID-19 Services in Florida's Farmworker Corridor.

COVID-19 elucidated the urgency for health justice advocacy for Latinx farmworkers in Florida. While deemed essential, farmworkers' value was not reflected in policy responses to ensure their protection. The deficiency of culturally and linguistically relevant guidance from government agencies and state restrictions requiring identification for COVID-19 services were impediments to farmworkers accessing care. Equitable access was increased through a statewide promotor de salud network delivering health information and mobilizing vaccine partners to serve farmworkers at high risk of COVID-19 infection. (Am J Public Health. 2024;114(S1):S74-S77. https://doi.org/10.2105/AJPH.2023.307454).

Prevalence of diabetic foot and its risk factors in the state of espirito santo, brazil

Introdução: O Pé Diabético (PD) é a principal causa de amputações não traumáticas nos países ocidentais, causando morte ou incapacidade física e mental, má qualidade de vida e alto custo para a sociedade. Objetivo: Analisar a prevalência de DF e fatores de risco relacionados na população diabética residente no Estado do Espírito Santo, Brasil. Métodos: Estudo transversal, descritivo, com delineamento de série temporal, utilizando dados secundários de morbidade de indivíduos com DF residentes no Estado do Espírito Santo, cadastrados e acompanhados pelo Sistema de Cadastro e Acompanhamento de Hipertensos e Diabéticos. Resultados: Dos 64.196 diabéticos, 3,9% tinham DM tipo 1, 10,9% DM tipo 2 e 85,2% eram hipertensos. A prevalência de DF foi de 2,9% no DM tipo 1, 3,3% no DM tipo 2 e 4,5% no DM com hipertensão. Maiores taxas de DF foram observadas no sexo masculino, com idade acima de 60 anos no DM tipo 1 e tipo 2, e até 19 anos no DM com hipertensão, tabagismo, sedentarismo, Infarto Agudo do Miocárdio (IAM), AVC e Doença Renal Crônica (DRC) ). Nos indivíduos com excesso de peso, a prevalência de DF foi maior apenas no DM tipo 1. Houve associação significativa em todas as variáveis exceto sobrepeso em ambos os tipos de DM, sedentarismo e acidente vascular cerebral no DM tipo 1. Conclusão: Os achados mostraram importantes prevalências de DF, com maior concentração em homens com mais de 60 anos, sobre tabagismo, sedentarismo, IAM, AVC e DRC, com associação estatística significativa nas variáveis analisadas, com exceção do excesso de peso em ambos os tipos de DM, como bem como sedentarismo e acidente vascular cerebral no DM tipo 1.

Introduction: Diabetic Foot (DF) is the leading cause of non-traumatic amputations in Western countries, causing death or physical and mental disability, poor quality of life and high cost to society. Objetive: To analyze the prevalence of DF and related risk factors in the diabetic population residing in Espírito Santo State, Brazil. Methods: Cross-sectional, descriptive study with time series design, using secondary data on morbidity of individuals with DF living in the State of Espírito Santo, registered and followed by the Hypertensive and Diabetic Registration and Monitoring System. Results: From 64,196 diabetic patients, 3.9% had Type 1 DM, 10.9% Type 2 DM and 85.2% had hypertension. The prevalence of DF was 2.9% in type 1 DM, 3.3% in type 2 DM and 4.5% in DM with hypertension. Higher rates of DF were observed in males, aged over 60 years in type 1 and type 2 DM, and up to 19 years in DM with hypertension, smoking, sedentary lifestyle, Acute Myocardial Infarction (AMI), stroke and Cronic Kidney disease (CKD). In overweight individuals, the prevalence of DF was higher only in type 1 DM. There was a significant association in all variables except overweight in both types of DM, sedentary lifestyle and stroke in type 1 DM. Conclusion: Findings showed important prevalence of DF, with higher concentration in men older than 60 years, on smoking, sedentary lifestyle, AMI, stroke and CKD, with significant statistical association in the analized variables, except for overweight in both types of DM, as well as sedentary lifestyle and stroke in type 1 DM.

B Chromosomes in Psalidodon scabripinnis (Characiformes, Characidae) Species Complex.

B chromosomes are extra-genomic components of cells found in individuals and in populations of some eukaryotic organisms. They have been described since the first observations of chromosomes, but several aspects of their biology remain enigmatic. Despite being present in hundreds of fungi, plants, and animal species, only a small number of B chromosomes have been investigated through high-throughput analyses, revealing the remarkable mechanisms employed by these elements to ensure their maintenance. Populations of the Psalidodon scabripinnis species complex exhibit great B chromosome diversity, making them a useful material for various analyses. In recent years, important aspects of their biology have been revealed. Here, we review these studies presenting a comprehensive view of the B chromosomes in the P. scabripinnis complex and a new hypothesis regarding the role of the B chromosome in the speciation process.

In-conduit capture of sub-micron volcanic ash particles via turbophoresis and sintering.

Ash emission in explosive silicic eruptions can have widespread impacts for human health, agriculture, infrastructure, and aviation. Estimates of the total grainsize distribution (TGSD) generated during explosive magma fragmentation underpins eruption models and ash dispersal forecasts. Conventionally, the TGSD constrained via erupted deposits is assumed to match the TGSD produced at explosive fragmentation. Here we present observations from within the vent of a recent rhyolitic eruption (Cordón Caulle, Chile, 2011-2012), demonstrating that fine (<63 µm diameter) and ultra-fine (<2.5 µm diameter) ash particles are captured and sintered to fracture surfaces, and thus sequestered in the shallow subsurface, rather than emitted. We establish a conceptual model-uniquely contextualised through a combination of syn-eruptive observations and detailed post-eruption field investigation-in which turbophoresis (particle migration towards zones of lower turbulence) and rapid sintering create an inverse relationship between particle size and the probability of its subsurface capture. Such size-dependent capture efficiency preferentially removes submicron-diameter ash from the erupted componentry, decoupling the erupted size distribution from magmatic source conditions and potentially playing an important role in modulating eruption dynamics.

Eruption of ultralow-viscosity basanite magma at Cumbre Vieja, La Palma, Canary Islands.

The viscosity of magma exerts control on all aspects of its migration through the crust to eruption. This was particularly true for the 2021 eruption of Cumbre Vieja (La Palma), which produced exceptionally fast and fluid lava at high discharge rates. We have performed concentric cylinder experiments to determine the effective viscosities of the Cumbre Vieja magma, while accounting for its chemistry, crystallinity, and temperature. Here we show that this event produced a nepheline-normative basanite with the lowest viscosity of historical basaltic eruptions, exhibiting values of less than 10 to about 160 Pa s within eruption temperatures of ~1200 to ~1150 °C. The magma's low viscosity was responsible for many eruptive phenomena that lead to particularly impactful events, including high-Reynolds number turbulent flow and supercritical states. Increases in viscosity due to crystallization-induced melt differentiation were subdued in this eruption, due in part to subtle degrees of silica enrichment in alkaline magma.

Premio de Investigación SCHOT 2020: desarrollo y validación de un modelo multivariables de predicción de estadía hospitalaria en pacientes mayores de 65 años sometidos artroplastia total de cadera electiva en Chile utilizando aprendizaje de máquinas / 2020 SCHOT Research award: Development an a multivariable prediction model of hospital stay in elderly chilean patients undergoing elective total hip arthroplasty using machine learning

INTRODUCCIÓN La predicción de la estadía hospitalaria luego de una artroplastia total de cadera (ATC) electiva es crucial en la evaluación perioperatoria de los pacientes, con un rol determinante desde el punto de vista operacional y económico. Internacionalmente, se han empleado macrodatos (big data, en inglés) e inteligencia artificial para llevar a cabo evaluaciones pronósticas de este tipo. El objetivo del presente estudio es desarrollar y validar, con el empleo del aprendizaje de máquinas (machine learning, en inglés), una herramienta capaz de predecir la estadía hospitalaria de pacientes chilenos mayores de 65 años sometidos a ATC por artrosis. MATERIALES Y MÉTODOS Empleando los registros electrónicos de egresos hospitalarios anonimizados del Departamento de Estadísticas e Información de Salud (DEIS), se obtuvieron los datos de 8.970 egresos hospitalarios de pacientes sometidos a ATC por artrosis entre los años 2016 y 2018. En total, 15 variables disponibles en el DEIS, además del porcentaje de pobreza de la comuna de origen del paciente, fueron incluidos para predecir la probabilidad de que un paciente presentara una estadía acortada (< 3 días) o prolongada (> 3 días) luego de la cirugía. Utilizando técnicas de aprendizaje de máquinas, 8 algoritmos de predicción fueron entrenados con el 80% de la muestra. El 20% restante se empleó para validar las capacidades predictivas de los modelos creados a partir de los algoritmos. La métrica de optimización se evaluó y ordenó en un ranking utilizando el área bajo la curva de característica operativa del receptor (area under the receiver operating characteristic curve, AUC-ROC, en inglés), que corresponde a cuan bien un modelo puede distinguir entre dos grupos. RESULTADOS El algoritmo XGBoost obtuvo el mejor desempeño, con una AUC-ROC promedio de 0,86 (desviación estándar [DE]: 0,0087). En segundo lugar, observamos que el algoritmo lineal de máquina de vector de soporte (support vector machine, SVM, en inglés) obtuvo una AUC-ROC de 0,85 (DE: 0,0086). La importancia relativa de las variables explicativas demostró que la región de residencia, el servicio de salud, el establecimiento de salud donde se operó el paciente, y la modalidad de atención son las variables que más determinan el tiempo de estadía de un paciente. DISCUSIÓN El presente estudio desarrolló algoritmos de aprendizaje de máquinas basados en macrodatos chilenos de libre acceso, y logró desarrollar y validar una herramienta que demuestra una adecuada capacidad discriminatoria para predecir la probabilidad de estadía hospitalaria acortada versus prolongada en adultos mayores sometidos a ATC por artrosis. CONCLUSIÓN Los algoritmos creados a traves del empleo del aprendizaje de máquinas permiten predecir la estadía hospitalaria en pacientes chilenos operado de artroplastia total de cadera electiva

Introduction The prediction of the length of hospital stay after elective total hip arthroplasty (THA) is crucial in the perioperative evaluation of the patients, and it plays a decisive role from the operational and economic point of view. Internationally, big data and artificial intelligence have been used to perform prognostic evaluations of this type. The present study aims to develop and validate, through the use of artificial intelligence (machine learning), a tool capable of predicting the hospital stay of patients over 65 years of age undergoing THA for osteoarthritis. Material and Methods Using the electronic records of hospital discharges de-identified from the Department of Health Statistics and Information (Departamento de Estadísticas e Información de Salud, DEIS, in Spanish), the data of 8,970 hospital discharges of patients who had undergone THA for osteoarthritis between 2016 and 2018 were obtained. A total of 15 variables available in the DEIS registry, in addition to the poverty rate in the patient's borough of origin were included to predict the probability that a patient would have a shortened (< 3 days) or prolonged (> 3 days) stay after surgery. By using machine learning techniques, 8 prediction algorithms were trained with 80% of the sample. The remaining 20% was used to validate the predictive capabilities of the models created from the algorithms. The optimization metric was evaluated and ranked using the area under the receiver operating characteristic curve (AUC-ROC), which corresponds to how well a model can distinguish between two groups. Results The XGBoost algorithm had the best performance, with an average AUC-ROC of 0.86 (standard deviation [SD]: 0.0087). Secondly, we observed that the linear support vector machine (SVM) algorithm obtained an AUC-ROC of 0.85 (SD: 0.0086). The relative importance of the explanatory variables showed that the region of residence, the administrative health service, the hospital where the patient was operated on, and the care modality are the variables that most determine the length of stay. Discussion The present study developed machine learning algorithms based on freeaccess Chilean big data, which helped create and validate a tool that demonstrates an adequate discriminatory capacity to predict shortened versus prolonged hospital stay in elderly patients undergoing elective THA. Conclusion The algorithms created through the use of machine learning allow to predict the hospital stay in Chilean patients undergoing elective total hip arthroplasty Introduction The prediction of the length of hospital stay after elective total hip arthroplasty (THA) is crucial in the perioperative evaluation of the patients, and it plays a decisive role from the operational and economic point of view. Internationally, big data and artificial intelligence have been used to perform prognostic evaluations of this type. The present study aims to develop and validate, through the use of artificial intelligence (machine learning), a tool capable of predicting the hospital stay of patients over 65 years of age undergoing THA for osteoarthritis. Material and Methods Using the electronic records of hospital discharges de-identified from the Department of Health Statistics and Information (Departamento de Estadísticas e Información de Salud, DEIS, in Spanish), the data of 8,970 hospital discharges of patients who had undergone THA for osteoarthritis between 2016 and 2018 were obtained. A total of 15 variables available in the DEIS registry, in addition to the poverty rate in the patient's borough of origin were included to predict the probability that a patient would have a shortened (< 3 days) or prolonged (> 3 days) stay after surgery. By using machine learning techniques, 8 prediction algorithms were trained with 80% of the sample. The remaining 20% was used to validate the predictive capabilities of the models created from the algorithms. The optimization metric was evaluated and ranked using the area under the receiver operating characteristic curve (AUC-ROC), which corresponds to how well a model can distinguish between two groups. Results The XGBoost algorithm had the best performance, with an average AUC-ROC of 0.86 (standard deviation [SD]: 0.0087). Secondly, we observed that the linear

Spinal malformations in a naturally isolated Neotropical fish population.

Fish populations that reside in completely isolated freshwater ecosystems are rare worldwide. The Vila Velha State Park (VVSP), located in southern Brazil, is recognized for its arenitic formations called sinkholes (furnas), which are completely isolated. Fish populations within, such as those of Psalidodon aff. fasciatus, often develop vertebral malformations due to this isolation from other conspecifics and other species. In this study, we analyzed geometric morphology in digital radiographs to identify congenital deformations of Psalidodon aff. fasciatus in Furna 2 of VVSP. We found many fish with spinal deformities, including wide variation in the number of caudal vertebrae and corporal deformations related to a flattened body and spinal curvature. Females were more affected than males. We also demonstrated that these deformations reflect inbreeding and an absence of gene flow in the population. In conclusion, isolated populations such as fish species in furnas are potential models for evo-devo research.

Chromosomal Instability and Origin of B Chromosomes in the Amazonian Glass Tetra Moenkhausia oligolepis (Günther, 1864) (Characiformes, Characidae).

B chromosomes occur in different species of the small characid fishes of the genus Moenkhausia. These supernumerary elements, that do not recombine with chromosomes of the standard A complement and follow their own evolutionary mechanism vary in number, morphology, and distribution. Here, we show karyotypic data of individuals of 2 populations of Moenkhausia oligolepis of the Brazilian Amazon (Pedro Correia and Taboquinha streams, Tocantins river basin), both with a diploid number of 50 chromosomes and karyotypic formula of 10m + 32sm + 8a. In addition to the normal complement, we also observed the occurrence of B chromosomes in the 2 populations with intra- and interindividual variation ranging from 0 to 10 Bs, independent of sex. The C-banding pattern evidenced heterochromatic blocks located mainly in the pericentromeric region of the chromosomes, while the B chromosomes appeared euchromatic. Silver-stained nucleolus organizer regions were identified in multiples sites, and some of these blocks were positive when stained with chromomycin A3. The karyotype analysis and the application of whole-chromosome painting in populations of M. oligolepis reinforce the conservation of the basal diploid number for the genus, as well as the evolutionary tendency in these fishes to carry B chromosomes. Both populations turned out to be in different stages of stability and expansion of their B chromosomes. We further suggest that the origin of these chromosomes is due to the formation of isochromosomes. Here, we identified a pair of complement A chromosomes involved in this process.

Long-term persistence of supernumerary B chromosomes in multiple species of Astyanax fish.

BACKGROUND: Eukaryote genomes frequently harbor supernumerary B chromosomes in addition to the "standard" A chromosome set. B chromosomes are thought to arise as byproducts of genome rearrangements and have mostly been considered intraspecific oddities. However, their evolutionary transcendence beyond species level has remained untested. RESULTS: Here we reveal that the large metacentric B chromosomes reported in several fish species of the genus Astyanax arose in a common ancestor at least 4 million years ago. We generated transcriptomes of A. scabripinnis and A. paranae 0B and 1B individuals and used these assemblies as a reference for mapping all gDNA and RNA libraries to quantify coverage differences between B-lacking and B-carrying genomes. We show that the B chromosomes of A. scabripinnis and A. paranae share 19 protein-coding genes, of which 14 and 11 were also present in the B chromosomes of A. bockmanni and A. fasciatus, respectively. Our search for B-specific single-nucleotide polymorphisms (SNPs) identified the presence of B-derived transcripts in B-carrying ovaries, 80% of which belonged to nobox, a gene involved in oogenesis regulation. Importantly, the B chromosome nobox paralog is expressed > 30× more than the A chromosome paralog. This indicates that the normal regulation of this gene is altered in B-carrying females, which could potentially facilitate B inheritance at higher rates than Mendelian law prediction. CONCLUSIONS: Taken together, our results demonstrate the long-term survival of B chromosomes despite their lack of regular pairing and segregation during meiosis and that they can endure episodes of population divergence leading to species formation.

Analysis of Diabetes Mellitus-Related Amputations in the State of Espírito Santo, Brazil.

Background and objectives: Diabetes mellitus (DM) stands out among the most important public health problems worldwide since it represents a high burden on health systems and is associated with higher hospitalization rates, and a higher incidence of cardiovascular diseases. Amputations are among the most common complications, leading to disability and increasing care costs. This research aims to analyze the prevalence of DM-related amputations, comorbidities and associated risk factors in the diabetic population residing in the State of Espírito Santo, Brazil. Materials and Methods: This is a quantitative, exploratory, cross-sectional study with a time series design and the use of secondary data registered and followed by the system of Registration and Monitoring of Hypertension and Diabetes-SisHiperdia. Results: The sample consisted of 64,196 diabetic patients, out of them, 3.9% had type 1 DM, 10.9% with type 2 DM, and 85.2% with DM coexisting with hypertension. Most were female (66.6%), aged 40 to 59 years (45.6%), and 60 years and older (45.2%). The prevalence of DM-related amputations in the analyzed sample was 1.2% in type 1 DM, 1.5% in type 2 DM, and 2.2% in concomitant DM and hypertension. Higher amputation rates were observed in males in the age group above 60 years in type 1 DM and type 2 DM and were slightly higher in the age groups up to 29 years in DM with hypertension. A higher prevalence of amputation was related to smoking, physical inactivity, acute myocardial infarction (AMI), stroke, chronic kidney disease (CKD), and diabetic foot (DF) in all types of DM. Conclusions: The present study showed a significant prevalence of DM-related amputations. An increased prevalence was evidenced when correlated with smoking, physical inactivity, AMI, stroke, CKD, and DF with significant statistical associations, except for a sedentary lifestyle in type 1 DM.

Dynamics of Replication and Nuclear Localization of the B Chromosome in Kidney Tissue Cells in Astyanax scabripinnis (Teleostei: Characidae).

B chromosomes are extra genomic compounds found in different taxonomic groups, including plants and animals. Obtaining patterns of resolutive chromosomal bands is necessary to understand the nuclear organization, variability and nature of B chromosome chromatin and possible transcriptional regions. In this study, we analyzed 35 Astyanax scabripinnis specimens sampled from Fazenda Lavrinha, a stream in the Paraíba do Sul river basin, Brazil. Through the incorporation of the thymidine analog 5'-bromo-2'-deoxyuridine (5-BrdU) in vivo, it was possible to recognize the replicating regions of the B chromosome at the beginning of the S phase, differentially characterized in relationship to the regions of late replication. In this perspective, it is possible to suggest that the B chromosome of this species possesses a territory and the chromatin accessible for transcription, especially in the light (i.e., early replicating) bands (p1.1; p1.3; and p2.1 and q1.1, q1.3, q2.1, and q2.2). The late-replicating regions are corresponding to the blocks of constitutive heterochromatin. They show a preferential accumulation of satellite DNA As51. By the use of the fluorochrome chromomycin A3 (CMA3), it was possible to identify GC-rich chromosomal regions, corresponding to late-replicating parts of genome, confirming the revealed data by the replication banding and C-banding. In addition, the analysis by confocal microscopy in kidney cells indicates the location of a peripheral anchorage of this chromosome in the nuclear lamina, reinforcing the idea of downregulation of the associated regions.

Differential Expression of Genes Related to Sexual Determination Can Modify the Reproductive Cycle of Astyanax scabripinnis (Characiformes: Characidae) in B Chromosome Carrier Individuals.

The species complex Astyanax scabripinnis is one of the most studied with respect to origin, distribution, and frequency of B chromosomes, and is considered a model organism for evolutionary studies. Research using population inferences about the occurrence and frequency of the B chromosome shows seasonal variation between sexes, which is associated with the presence of this supernumerary element. We hypothesized that the B chromosome could influence the sex ratio of these animals. Based on this assumption, the present work aimed to investigate if differences exist among levels of gene expression with qRT-PCR of the amh (associated with testicular differentiation) and foxl2a (associated with ovarian differentiation) genes between B-carrier and non-B-carrier individuals. The results showed that for the amh gene, the difference in expression between animals with B chromosomes was not accentuated compared to that in animals without this chromosome. Expression of foxl2a in B-carrier females, however, was reduced by 73.56% compared to females that lacked the B chromosome. Males had no difference in expression of the amh and foxl2a genes between carriers and non-carriers of the B chromosome. Results indicate that the presence of B chromosomes is correlated with the differential expression of sex-associated genes. An analysis of these results integrated with data from other studies on the reproductive cycle in the same species reveals that this difference in expression may be expanding the reproductive cycle of the species.

Differential Expression of dmrt1 in Astyanax scabripinnis (Teleostei, Characidade) Is Correlated with B Chromosome Occurrence.

Astyanax is an abundant fish genus in South America. Some species of this group are characterized by the presence of B chromosomes and absence of morphologically differentiated sex chromosomes. In this study, we used quantitative real-time polymerase chain reaction to characterize mRNA expression of dmrt1 in Astyanax scabripinnis gonads. Maturing gonads of males with the B chromosome overexpressed dmrt1. Our findings suggest that B chromosomes may have an adaptive role in A. scabripinnis sex determination and maintenance.

Combined effusive-explosive silicic volcanism straddles the multiphase viscous-to-brittle transition.

Magma is a viscoelastic fluid that can support fracture propagation when local shear stresses are high, or relax and flow when shear stresses are low. Here we present experiments to confirm this using synthetic and natural magmatic liquids across eruptive conditions and use Maxwell's linear viscoelasticity to parameterize our results and predict the maximum stresses that can be supported during flow. This model proves universal across a large range of liquid compositions, temperatures, crystallinity and rates of strain relevant to shallow crustal magma ascent. Our results predict that the 2008 Volcán Chaitén eruption resided in the viscous field at the onset of magma ascent, but transitioned to a mixed viscous-brittle regime during degassing, coincident with the observed combined effusive-explosive behaviour during dome extrusion. Taking a realistic maximum effusive ascent rate, we propose that silicic eruptions on Earth may straddle the viscous-to-brittle transition by the time they reach the surface.

B Chromosome Diversity and Repetitive Sequence Distribution in an Isolated Population of Akodon montensis (Rodentia, Sigmodontinae).

B chromosomes are supernumerary chromosomes found in the karyotypes of approximately 15% of all eukaryotic species. They present parasitic behavior and do not follow the standard Mendelian pattern of inheritance, resulting in an imbalance in gametogenesis. The evolutionary dynamics of B chromosomes is still unknown for many species, but studies indicate that the accumulation of repetitive sequences plays an important role in the differentiation of these elements. We analyzed morphology, frequency, and possible homologies amongst different B chromosomes found in an isolated Akodon montensis population in southern Brazil. Repetitive sequences (18S, 5S rDNA and telomeric sequences) were used to test for their accumulation on the supernumerary chromosomes and describe their localization in the species. The results indicate 4 different B chromosome morphotypes, and DNA libraries were generated for 3 of them. 18S rDNA was labelled polymorphically, except in the B chromosomes, whereas the 5S rDNA was located exclusively in an interstitial position on the long arm of chromosome 5. Chromosome painting with the B probes based on FISH revealed a homologous composition for all B chromosome morphotypes and no homology with the chromosomes in the A complement. B chromosomes found in this population may have a common origin and subsequently diversified in size and morphology.

Comparative cytogenetics of Astyanax (Teleostei: Characidae) from the upper Paraguay basin

Astyanax is one of the most abundant and diverse taxa of fishes in the Neotropical region. In order to increase the amount of cytogenetic information for Astyanax as well as to exhibit data to subsidize future taxonomic studies, this work analyzed three species of Astyanax: two species are cryptic, and are here reported to live in syntopy (A. abramis and A. lacustris); the first karyotype description for A. pirapuan is also presented. Cytogenetic analyzes reveal a diploid number of 2n=50 chromosomes for three species, yet with differences in their karyotype morphology. The physical mapping of 18S rDNA showed up to thirteen sites in A. pirapuan and two in A. abramis and A. lacustris. The physical mapping of 5S rDNA has proven to be an effective marker for the characterization of species of Astyanax studied in this work.(AU)

Astyanax é um dos táxons mais representados e diversos na região Neotropical. Com o intuito de aumentar as informações citogenéticas para Astyanax e apresentar dados que possam subsidiar estudos taxonômicos futuros, este trabalho traz uma análise citogenética de três espécies de Astyanax: duas espécies consideradas crípticas, aqui reportadas em sintopia (A. abramis e A. lacustris) e a primeira descrição cariotípica de A. pirapuan. As análises citogenéticas revelaram 2n=50 cromossomos para as três espécies, com diferença na morfologia cariotípica de cada uma. Foram observados apenas dois sítios de rDNA 18S em A. abramis e A. lacustris e até 13 para A. pirapuan. O mapeamento físico do rDNA 5S se mostrou como um marcador efetivo para a caracterização das espécies de Astyanax abordadas neste estudo.(AU)

Rapid laccolith intrusion driven by explosive volcanic eruption.

Magmatic intrusions and volcanic eruptions are intimately related phenomena. Shallow magma intrusion builds subsurface reservoirs that are drained by volcanic eruptions. Thus, the long-held view is that intrusions must precede and feed eruptions. Here we show that explosive eruptions can also cause magma intrusion. We provide an account of a rapidly emplaced laccolith during the 2011 rhyolite eruption of Cordón Caulle, Chile. Remote sensing indicates that an intrusion began after eruption onset and caused severe (>200 m) uplift over 1 month. Digital terrain models resolve a laccolith-shaped body ∼0.8 km3. Deformation and conduit flow models indicate laccolith depths of only ∼20-200 m and overpressures (∼1-10 MPa) that likely stemmed from conduit blockage. Our results show that explosive eruptions may rapidly force significant quantities of magma in the crust to build laccoliths. These iconic intrusions can thus be interpreted as eruptive features that pose unique and previously unrecognized volcanic hazards.