Home range of three turtle species in Central Yucatan. A comparative study.

Home range is a fundamental characteristic of an animal natural history. The study of home range provides information on the sites where organisms forage for food, find shelter, or locate mates. Home range size and shape can change throughout the lifespan of an organism, during the year, or across seasons, driven by resource availability and the basic needs for each organism. For freshwater and semi-aquatic turtles, home range is greatly affected by water availability, humidity, and temperature throughout the year, nevertheless demographic factors such age and sex are also important determinants of home range size. In this study we estimated home range and dispersal movements for Kinosternon creaseri, Terrapene yucatana, and Rhinoclemmys areolata in a semi-tropical dry forest in central Yucatán. For a two-year period, turtles were surveyed using hoop traps and visual encounters. Twenty-one individuals (5-8 per species) were equipped with radio transmitters to track them across the landscape. Distances between relocations and home range were compared across species seasons, sex, and interactions of these variables. Monthly average movements were positively correlated with rain in the three species studied. Home range of R. areolata was larger than those of K. creaseri and T. yucatana. Home range of the three studied species were larger during the wet season. Home range overlap index within same species individuals was higher during the rainy than dry season, but overall overlap is low between and within species.

Adaptation and validation of the Perceived Nutrition Environment Measures Survey for the Chilean context (NEMS-P-Ch)

There is an increasing interest in having validated instruments that can classify food environments due to their influence on eating behavior and nutritional status. In Chile, it is not known how people perceive food environments and only a few studies have adapted instruments to the Chilean context, all of which use objective measures. The aim of this study is to present the adaptation and validation of the Perceived Nutrition Environment Measures Survey (NEMS-P-Ch) for Chile using a cross-sectional, non-probability study. First, the NEMS-P was adapted in 3 stages: cultural translation and adaptation, expert judgment (focus groups), and cognitive interviews with a population similar to the target audience. Then, the adapted questionnaire (NEMS-P for Chile, NEMS-P-Ch) was tested on people responsible for buying food in their homes in the Metropolitan Region, Chile, for statistical validation. After 200 people completed the questionnaire a final version of the NEMS-P-Ch was generated with 48 questions and seven sections that measure food environments: home, food supply, restaurants and street. NEMS-P-Ch had acceptable reliability in more than half of the questions analyzed, with Cronbach's alpha values between 0.44 and 0.82. Acceptable values were also obtained for most of the questions when the consistency of the instrument was evaluated after applying it for the second time (n= 167). The NEMS-P-Ch adapted to the Chilean context showed acceptable validity and reliability. Having instruments adapted and validated to the national reality will promote their use and adaptation in other countries of the region and thus deepen the study of food environments in various territories and populations.

El creciente interés por contar con instrumentos validados que clasifiquen los ambientes alimentarios se debe a la influencia que estos tienen en la conducta alimentaria y el estado nutricional. En Chile, se desconoce cómo las personas perciben los ambientes alimentarios y son pocos los estudios que han adaptado instrumentos al contexto chileno, todos utilizando medidas objetivas. En este estudio se presenta la adaptación y validación para Chile de la Encuesta de Medición del Entorno Nutricional Percibido (NEMS-P-Ch). Estudio transversal, no probabilístico. Inicialmente, NEMS-P fue adaptado siguiendo 3 etapas: traducción y adaptación cultural, juicio de expertos (grupos focales) y entrevistas cognitivas con población similar a la audiencia objetivo. Luego, el cuestionario adaptado (NEMS-P-Ch) fue testeado en personas responsables de la compra de alimentos del hogar, Región Metropolitana, Chile, para finalmente validarlo estadísticamente. Tras su aplicación a 200 personas, se generó la última versión de NEMS-PCh, instrumento con 48 preguntas y 7 secciones que mide los ambientes alimentarios: doméstico, de abastecimiento, restauración y vía pública. NEMS-P-Ch mostró una confiabilidad aceptable en más de la mitad de las preguntas analizadas, con valores alfa de Cronbach entre 0,44 y 0,82. También se obtuvieron valores aceptables en la mayoría de las preguntas cuando se evaluó su consistencia al aplicarlo por segunda vez (n= 167). NEMS-P-Ch adaptado al contexto chileno mostró una validez y confiabilidad aceptables. Contar con instrumentos validados a la realidad nacional promoverá su uso, su adaptación en otros países de la región y la profundización del estudio de los ambientes alimentarios en diversos territorios y poblaciones.

Assessing genomic and ecological differentiation among subspecies of the rough-footed mud turtle, Kinosternon hirtipes.

Combining genetic and ecological measures of differentiation can provide compelling evidence for ecological and genetic divergence among lineages. The rough-footed mud turtle, Kinosternon hirtipes, is distributed from the Trans-Pecos region of Texas to the highlands of Central Mexico and contains 6 described subspecies, 5 of which are extant. We use ddRAD sequencing and species distribution models to assess levels of ecological and genetic differentiation among these subspecies. We also predict changes in climatically suitable habitat under different climate change scenarios and assess levels of genetic diversity and inbreeding within each lineage. Our results show that there is strong genetic and ecological differentiation among multiple lineages within K. hirtipes, and that this differentiation appears to be the result of vicariance associated with the Trans-Mexican Volcanic Belt. We propose changes to subspecies designations to more accurately reflect the evolutionary relationships among populations and assess threats to each subspecies.

Evolutionary transitions in diet influence the exceptional diversification of a lizard adaptive radiation.

BACKGROUND: Diet is a key component of a species ecological niche and plays critical roles in guiding the trajectories of evolutionary change. Previous studies suggest that dietary evolution can influence the rates and patterns of species diversification, with omnivorous (animal and plant, 'generalist') diets slowing down diversification compared to more restricted ('specialist') herbivorous and carnivorous diets. This hypothesis, here termed the "dietary macroevolutionary sink" hypothesis (DMS), predicts that transitions to omnivorous diets occur at higher rates than into any specialist diet, and omnivores are expected to have the lowest diversification rates, causing an evolutionary sink into a single type of diet. However, evidence for the DMS hypothesis remains conflicting. Here, we present the first test of the DMS hypothesis in a lineage of ectothermic tetrapods-the prolific Liolaemidae lizard radiation from South America. RESULTS: Ancestral reconstructions suggest that the stem ancestor was probably insectivorous. The best supported trait model is a diet-dependent speciation rate, with independent extinction rates. Herbivory has the highest net diversification rate, omnivory ranks second, and insectivory has the lowest. The extinction rate is the same for all three diet types and is much lower than the speciation rates. The highest transition rate was from omnivory to insectivory, and the lowest transition rates were between insectivory and herbivory. CONCLUSIONS: Our findings challenge the core prediction of the DMS hypothesis that generalist diets represent an 'evolutionary sink'. Interestingly, liolaemid lizards have rapidly and successfully proliferated across some of the world's coldest climates (at high elevations and latitudes), where species have evolved mixed arthropod-plant (omnivore) or predominantly herbivore diets. This longstanding observation is consistent with the higher net diversification rates found in both herbivory and omnivory. Collectively, just like the evolution of viviparity has been regarded as a 'key adaptation' during the liolaemid radiation across cold climates, our findings suggest that transitions from insectivory to herbivory (bridged by omnivory) are likely to have played a role as an additional key adaptation underlying the exceptional diversification of these reptiles across extreme climates.

Moving bar of light evokes vectorial spatial selectivity in the immobile rat hippocampus.

Visual cortical neurons encode the position and motion direction of specific stimuli retrospectively, without any locomotion or task demand1. The hippocampus, which is a part of the visual system, is hypothesized to require self-motion or a cognitive task to generate allocentric spatial selectivity that is scalar, abstract2,3 and prospective4-7. Here we measured rodent hippocampal selectivity to a moving bar of light in a body-fixed rat to bridge these seeming disparities. About 70% of dorsal CA1 neurons showed stable activity modulation as a function of the angular position of the bar, independent of behaviour and rewards. One-third of tuned cells also encoded the direction of revolution. In other experiments, neurons encoded the distance of the bar, with preference for approaching motion. Collectively, these demonstrate visually evoked vectorial selectivity (VEVS). Unlike place cells, VEVS was retrospective. Changes in the visual stimulus or its predictability did not cause remapping but only caused gradual changes. Most VEVS-tuned neurons behaved like place cells during spatial exploration and the two selectivities were correlated. Thus, VEVS could form the basic building block of hippocampal activity. When combined with self-motion, reward or multisensory stimuli8, it can generate the complexity of prospective representations including allocentric space9, time10,11 and episodes12.

Transcatheter stent implantation in a child with severe stenosis of the inferior caval vein secondary to injury.

Stenosis of the Inferior Caval Vein is rarely encountered in the paediatric setting. A 5-year-old male sustained severe injuries secondary to a fall from a three story balcony and was subsequently found to have severe stenosis of the inferior caval vein resulting in extensive lymphatic drainage with chylothorax, chyloperitoneum, and severe abdominal ascites. This was successfully treated with transcatheter stent placement resulting in complete resolution of the stenosis and significant clinical improvement allowing for transfer to a rehabilitation centre and eventual discharge home.

Disturbance reinforces community assembly processes differentially across spatial scales.

BACKGROUND AND AIMS: There is a paucity of empirical research and a lack of predictive models concerning the interplay between spatial scale and disturbance as they affect the structure and assembly of plant communities. We proposed and tested a trait dispersion-based conceptual model hypothesizing that disturbance reinforces assembly processes differentially across spatial scales. Disturbance would reinforce functional divergence at the small scale (neighbourhood), would not affect functional dispersion at the intermediate scale (patch) and would reinforce functional convergence at the large scale (site). We also evaluated functional and species richness of native and exotic plants to infer underlying processes. Native and exotic species richness were expected to increase and decrease with disturbance, respectively, at the neighbourhood scale, and to show similar associations with disturbance at the patch (concave) and site (negative) scales. METHODS: In an arid shrubland, we estimated species richness and functional dispersion and richness within 1 m2 quadrats (neighbourhood) nested within 100 m2 plots (patch) along a small-scale natural disturbance gradient caused by an endemic fossorial rodent. Data for the site scale (2500 m2 plots) were taken from a previous study. We also tested the conceptual model through a quantitative literature review and a meta-analysis. KEY RESULTS: As spatial scale increased, disturbance sequentially promoted functional divergence, random trait dispersion and functional convergence. Functional richness was unaffected by disturbance across spatial scales. Disturbance favoured natives over exotics at the neighbourhood scale, while both decreased under high disturbance at the patch and site scales. CONCLUSIONS: The results supported the hypothesis that disturbance reinforces assembly processes differentially across scales and hampers plant invasion. The quantitative literature review and the meta-analysis supported most of the model predictions.

Modification of Transfer RNA Levels Affects Cyclin Aggregation and the Correct Duplication of Yeast Cells.

Codon usage bias (the preferential use of certain synonymous codons (optimal) over others is found at the organism level (intergenomic) within specific genomes (intragenomic) and even in certain genes. Whether it is the result of genetic drift due to GC/AT content and/or natural selection is a topic of intense debate. Preferential codons are mostly found in genes encoding highly-expressed proteins, while lowly-expressed proteins usually contain a high proportion of rare (lowly-represented) codons. While optimal codons are decoded by highly expressed tRNAs, rare codons are usually decoded by lowly-represented tRNAs. Whether rare codons play a role in controlling the expression of lowly- or temporarily-expressed proteins is an open question. In this work we approached this question using two strategies, either by replacing rare glycine codons with optimal counterparts in the gene that encodes the cell cycle protein Cdc13, or by overexpression the tRNA Gly that decodes rare codons from the fission yeast, Schizosaccharomyces pombe. While the replacement of synonymous codons severely affected cell growth, increasing tRNA levels affected the aggregation status of Cdc13 and cell division. These lead us to think that rare codons in lowly-expressed cyclin proteins are crucial for cell division, and that the overexpression of tRNA that decodes rare codons affects the expression of proteins containing these rare codons. These codons may be the result of the natural selection of codons in genes that encode lowly-expressed proteins.

Edema pulmonar de las alturas. A propósito de un caso / High Altitude Pulmonary Edema: About a Case

El edema pulmonar de las alturas es una condición clínica que se desarrolla en individuos que han estado en regiones a nivel del mar y que posteriormente ascienden rápidamente a altitudes por encima de los 2500 metros. Se describe el caso de un paciente de 26 años con cuadro clínico y hallazgos radiológicos típicos de esta patología, en quién inicialmente se sospechó infección por coronavirus dada la sintomatología y el contexto de pandemia actual

High altitude pulmonary edema is a clinical condition that develops in individuals who have been in regions at sea level and who subsequently have a rapid ascent to altitudes above 2500 meters. We present the case of a 26-year-old male with clinical presentation and radiological findings typical of this entity, in whom coronavirus infection was initially suspected given the signs and symptoms in context of the current pandemic

Endogenous and Foreign Nucleoid-Associated Proteins of Bacteria: Occurrence, Interactions and Effects on Mobile Genetic Elements and Host's Biology.

Mobile Genetic Elements (MGEs) are mosaics of functional gene modules of diverse evolutionary origin and are generally divergent from the hosts´ genetic background. Existing biases in base composition and codon usage of these elements` genes impose transcription and translation limitations that may affect the physical and regulatory integration of MGEs in new hosts. Stable appropriation of the foreign DNA depends on a number of host factors among which are the Nucleoid-Associated Proteins (NAPs). These small, basic, highly abundant proteins bind and bend DNA, altering its topology and folding, thereby affecting all known essential DNA metabolism related processes. Both chromosomally- (endogenous) and MGE- (foreign) encoded NAPs have been shown to exist in bacteria. While the role of host-encoded NAPs in xenogeneic silencing of both episomal (plasmids) and integrative MGEs (pathogenicity islands and prophages) is well acknowledged, less is known about the role of MGE-encoded NAPs in the foreign elements biology or their influence on the host's chromosome expression dynamics. Here we review existing literature on the topic, present examples on the positive and negative effects that endogenous and foreign NAPs exert on global transcriptional gene expression, MGE integrative and excisive recombination dynamics, persistence and transfer to suitable hosts and discuss the nature and relevance of synergistic and antagonizing higher order interactions between diverse types of NAPs.

The Type IV Secretion System of ICEAfe1: Formation of a Conjugative Pilus in Acidithiobacillus ferrooxidans.

The dispersal of mobile genetic elements and their gene cargo relies on type IV secretion systems (T4SS). In this work the ICEAfe1 Tra-type T4SS nanomachine, encoded in the publicly available genome of Acidithiobacillus ferrooxidans ATCC 23270TY, was characterized in terms of its organization, conservation, expression and mating bridge formation. Twenty-one conjugative genes grouped in four genetic clusters encode the ICEAfe1 T4SS, containing all the indispensable functions for the formation and stabilization of the pili and for DNA processing. The clusters' organization resembles that of other mobile genetic elements (such as plasmids and integrative and conjugative elements-ICEs). Sequence conservation, genetic organization and distribution of the tra system in the genomes of other sequenced Acidithiobacillus spp. suggests that the ICEAfe1 T4SS could mediate the lateral gene transfer between related bacteria. All ICEAfe1 T4SS genes are transcriptionally active and expressed from four independent operons. The transcriptional levels of selected marker genes increase in response to Mitomycin C treatment, a DNA damage elicitor that has acknowledged stimulatory effects on excision rates and gene expression of other ICEs, including ICEAfe1. Using a tailor-made pilin-antiserum against ICEAfe1 T4SS TraA pilin and epifluorescence microscopy, the presence of the conjugative pili on the cell surface of A. ferrooxidans could be demonstrated. Additionally, immunodetection assays, by immunogold, allowed the identification of pili-like extracellular structures. Together, the results obtained in this work demonstrate that the ICEAfe1 T4SS is phylogenetically conserved within the taxon, is expressed at mRNA and protein levels in vivo in the A. ferrooxidans type strain, and produces a pili-like structure of extracellular and intercellular localization in this model acidophile, supporting its functionality. Additional efforts will be required to prove conjugation of the ICEAfe1 or parts of this element through the cognate T4SS.

Pulmonary artery interventions after the arterial switch operation: Unique and significant risks.

BACKGROUND: In the modern era, results of the arterial switch operation (ASO) for transposition of the great arteries are excellent. However, because of the LeCompte maneuver, there may be a propensity for development of pulmonary artery stenosis. We encountered atypical complications of pulmonary artery stenting in patients after the ASO, including aorto-pulmonary fistula and coronary compression. METHODS: We performed a 10-year retrospective review of catheterizations performed in patients after ASO in our institution with a focus on adverse events. RESULTS: Diagnostic and interventional catheterizations were performed in 47 patients. In 29 patients, 37 interventional procedures performed, which included pulmonary artery angioplasty and/or stenting. In this group, there were five major adverse events (14%), including three aorto-pulmonary fistulae and one coronary artery compression among patients having stent implantation or stent redilation. In addition, there were 6/37 (16%) intended stent procedures, which were aborted because there appeared to be high-risk of significant adverse events. CONCLUSIONS: This review suggests that percutaneous intervention on pulmonary artery stenosis after ASO has high-risk and should be undertaken advisedly. Prior thorough evaluation of coronary arteries is mandatory as coronary reimplantation sites may be adjacent to sites of pulmonary artery stenosis. Furthermore, if pulmonary artery stent implantation or stent redilation is contemplated, the risk of stent fracture and possible AP fistula should be recognized. Primary use of reinforced covered stents should be considered.

¿Cómo y por qué migrar hacia el informe radiológico estructurado contextualizado? / How and Why to Migrate to Radiology Structured and Contextualized Report?

Los informes estructurados contextualizados cumplen tres características fundamentales: tienen una estructura uniforme que responde una pregunta clínica, son el producto de listas de chequeo estandarizadas o de árboles de conocimiento previamente concertados con equipos clínicos multidisciplinarios y se construyen a partir de cuadros de selección de atributos incorporados en los sistemas de informe electrónicos, adicionalmente, el atributo contextualizado hace referencia a la capacidad del informe de responder las preguntas clínicas de la situación actual del paciente, otorgando información relevante de forma concisa y clara a los médicos tratantes. Dentro de las principales ventajas de migrar hacia el informe estructurado se encuentran la uniformidad y la alta calidad del informe, el aumento en la concordancia intra e interobservador, así como la reducción de las tasas de error diagnóstico y una mejora significativa en la comunicación con los médicos tratantes. Se presenta una revisión temática que abarca las características esenciales del informe estructurado contextualizado, los argumentos a favor y en contra de este, los pasos recomendados para su implementación y las oportunidades de mejora hacia el futuro.

Structured reporting in radiology fulfill three fundamental characteristics: they have a uniform structure that answers a clinical question, they are the product of standardized checklists or of knowledge trees previously arranged with multidisciplinary clinical teams, and they are incorporated in option-selection boxes available in electronic reporting systems. Among the main advantages of migrating towards structured reporting are the uniformity and high quality of the report, the increase in intra and interobserver concordance, as well as the reduction of the diagnostic error rates and a significant improvement in communication with the clinical practitioner. This thematic review covers the essential characteristics of the structured report, the arguments for and against it, the recommended steps for its implementation, and the future opportunities for improvement.

First-in-Human Closed-Chest Transcatheter Superior Cavopulmonary Anastomosis.

BACKGROUND: In the care of patients with congenital heart disease, percutaneous interventional treatments have supplanted many surgical approaches for simple lesions, such as atrial septal defect. By contrast, complex congenital heart defects continue to require open-heart surgery. In single-ventricle patients, a staged approach is employed, which requires multiple open-heart surgeries and significant attendant morbidity and mortality. A nonsurgical transcatheter alternative would be attractive. OBJECTIVES: The authors sought to show the feasibility of catheter-only, closed-chest, large-vessel anastomosis (superior vena cava and pulmonary artery [PA] or bidirectional Glenn operation equivalent) in a patient. METHODS: In preclinical testing over a decade, the authors developed the techniques and technology needed for nonsurgical crossing from a donor (superior vena cava) to a recipient (PA) vessel and endovascular stent-based anastomosis of those blood vessels. The authors undertook this transcatheter approach for an adult with untreated congenital heart disease with severe cyanosis and significant surgical risk. They rehearsed the procedure step by step using contrast-enhanced cardiac computed tomography and a patient-specific 3-dimensional printed heart model. RESULTS: The authors describe a first-in-human, fully percutaneous superior cavopulmonary anastomosis (bidirectional Glenn operation equivalent). The patient, a 35-year-old woman, was homebound due to dyspnea and worsening cyanosis. She was diagnosed with functional single ventricle and very limited pulmonary blood flow. The heart team believed surgical palliation conferred high operative risk due to the patient's complete condition. With the percutaneous procedure, the patient recovered uneventfully and remained improved clinically after 6 months. CONCLUSIONS: This procedure may provide a viable alternative to one of the foundational open-heart surgeries currently performed to treat single-ventricle congenital heart disease.

Stenting of the ascending aorta revisited.

Despite few institutions stenting the ascending aorta, it has been discouraged because of the proximity of the aortic valve, the coronary artery orifices, and the aortic arch branches. We describe a small case series of patients having acquired stenosis of the ascending that was relieved successfully by stenting. © 2017 Wiley Periodicals, Inc.

The importance of scale-dependent ravine characteristics on breeding-site selection by the Burrowing Parrot, Cyanoliseus patagonus.

In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic morphological characteristics followed by extrinsic variables associated to human disturbance. Likewise, within reproductive ravines, intrinsic characteristics are more strongly related to the number of nests. The probability of producing eggs, however, was related only to distance to roads and human settlements. Patterns suggest that C. patagonus mainly selects nesting sites based on intrinsic morphological characteristics of ravines. Scale differences in the importance of ravine characteristics could be a consequence of the particular orography of the breeding habitat. The arrangement of resources is associated to the location of the gullies rather than to individual ravines, determining the spatial availability and disposition of resources and disturbances. Thus, nest selection is influenced by intrinsic characteristics that maximize the fitness of individuals. Scaling in nest-selection is discussed under an optimality approach that partitions patch selection based on foraging theory.

Disturbance by an endemic rodent in an arid shrubland is a habitat filter: effects on plant invasion and taxonomical, functional and phylogenetic community structure.

Background and Aims: Disturbance often drives plant invasion and may modify community assembly. However, little is known about how these modifications of community patterns occur in terms of taxonomic, functional and phylogenetic structure. This study evaluated in an arid shrubland the influence of disturbance by an endemic rodent on community functional divergence and phylogenetic structure as well as on plant invasion. It was expected that disturbance would operate as a habitat filter favouring exotic species with short life cycles. Methods: Sixteen plots were sampled along a disturbance gradient caused by the endemic fossorial rodent Spalacopus cyanus , measuring community parameters and estimating functional divergence for life history traits (functional dispersion index) and the relative contribution to functional divergence of exotic and native species. The phylogenetic signal (Pagel's lambda) and phylogenetic community structure (mean phylogenetic distance and mean nearest taxon phylogenetic distance) were also estimated. The use of a continuous approach to the disturbance gradient allowed the identification of non-linear relationships between disturbance and community parameters. Key Results: The relationship between disturbance and both species richness and abundance was positive for exotic species and negative for native species. Disturbance modified community composition, and exotic species were associated with more disturbed sites. Disturbance increased trait convergence, which resulted in phylogenetic clustering because traits showed a significant phylogenetic signal. The relative contribution of exotic species to functional divergence increased, while that of natives decreased, with disturbance. Exotic and native species were not phylogenetically distinct. Conclusions: Disturbance by rodents in this arid shrubland constitutes a habitat filter over phylogeny-dependent life history traits, leading to phylogenetic clustering, and drives invasion by favouring species with short life cycles. Results can be explained by high phenotypic and phylogenetic resemblance between exotic and native species. The use of continuous gradients when studying the effects of disturbance on community assembly is advocated.

Melody® pulmonary valve implantation in two teenage patients with congenitally corrected transposition of the great arteries status after Senning atrial switch operation.

The Melody® transcatheter pulmonary valve system was developed for placement within right ventricle-to-pulmonary artery conduits in patients with CHD for treatment of stenosis or regurgitation, providing an alternative to open-heart surgery. Abnormal systemic venous connections altering the catheter course to the right ventricle-to-pulmonary artery conduit may present a challenge to Melody® valve implantation. We present two such cases, in which the Melody® valve was successfully implanted in teenage patients with congenitally corrected transposition of the great arteries after Senning atrial switch operation. Despite the abnormal catheter course, the right ventricle-to-pulmonary artery was approachable via the right femoral vein allowing for deployment of the Melody® valve in the appropriate position. This suggests that systemic vein-to-left atrium baffles are not prohibitive of Melody® valve implantation. This is an important implication considering the substantial population of ageing patients with CHD who have undergone atrial switch. Melody® valve implantation can be considered as a viable option for treatment of these patients if they develop right ventricle-to-pulmonary artery conduit failure.

Quantitative echocardiographic measures in the assessment of single ventricle function post-Fontan: Incorporation into routine clinical practice.

BACKGROUND: Quantitative echocardiographic measurements of single ventricular (SV) function have not been incorporated into routine clinical practice. METHODS: A clinical protocol, which included quantitative measurements of SV deformation (global circumferential and longitudinal strain and strain rate), standard deviation of time to peak systolic strain, myocardial performance index (MPI), dP/dT from an atrioventricular valve regurgitant jet, and superior mesenteric artery resistance index, was instituted for all patients with a history of Fontan procedure undergoing echocardiography. All measures were performed real time during clinically indicated studies and were included in clinical reports. RESULTS: A total of 100 consecutive patients (mean age = 11.95±6.8 years, range 17 months-31.3 years) completed the protocol between September 1, 2014 to April 29, 2015. Deformation measures were completed in 100% of the studies, MPI in 93%, dP/dT in 55%, and superior mesenteric artery Doppler in 82%. The studies were reviewed to assess for efficiency in completing the protocol. The average time for image acquisition was 27.4±8.8 (range 10-62 minutes). The average time to perform deformation measures was 10.8±5.5 minutes (range 5-35 minutes) and time from beginning of imaging to report completion was 53.4±13.7 minutes (range 27-107 minutes). There was excellent inter-observer reliability when deformation indices were blindly repeated. Patients with a single left ventricle had significantly higher circumferential strain and strain rate, longitudinal strain and strain rate, and dP/dT compared to a single right ventricle. There were no differences in quantitative indices of ventricular function between patients <10 vs. >10 years post-Fontan. CONCLUSION: Advanced quantitative assessment of SV function post-Fontan can be consistently and efficiently performed real time during clinically indicated echocardiograms with excellent reliability.