This survey aims to present the state of the art in analytic communication performance models, providing sufficiently detailed descriptions of particularly noteworthy efforts. Modeling the cost of ...communications in computer clusters is an important and challenging problem. It provides insights into the design of the communication pattern of parallel scientific applications and mathematical kernels and sets a clear ground for optimization of their deployment in the increasingly complex high-performance computing infrastructure. The survey provides background information on how different performance models represent the underlying platform and shows the evolution of these models over time from early clusters of single-core processors to present-day multi-core and heterogeneous platforms. Prospective directions for future research in the area of analytic communication performance modeling conclude the survey.
DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety ...of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region.
Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species), and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org). Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125) examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles.
This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide robust support for most morphologically based taxon concepts and also highlight key areas of taxonomic uncertainty worthy of reappraisal.
Purple Urine Bag Syndrome (PUBS) is a rare disorder seen in elderly persons, wherein the urinary bag and the tubing turn in to purple colour. It is usually seen in patients who are on urinary ...catheters for a long time. It consists of a change in the colour of the urine that turns purple in a very specific context.
We report the case of a paediatric female patient with Berdon Syndrome with symptoms consistent with urinary tract infection and purple urine discolouration. Urine test revealed leukocyturia and bacteriuria.
Several risk factors have been proposed regarding this syndrome. Among them the commonest are female gender, advanced age, kind of diet (increased dietary tryptophan), alkaline urine and diverse situations that leads to urinary retentions which allows bacteria to work on their substrate for a longer time. Although it is a process that is not associated with gravity, recognizing it is important as treatment is simple and can minimize patient and family distress.
to evaluate validity and concordance of Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP) and Screening Tool for Risk On Nutritional status and Growth (STRONGkids) screening ...tools for assessment of nutritional risk in pediatric inpatients.
Prospective longitudinal observational multicenter study in children aged 1 month or older admitted as inpatients. Weight, height, cause of admission, demographic data, length of stay, and nutritional interventions were recorded. STAMP and STRONGkids were applied within the first 72 h of admission. Anthropometric measurements were recorded again 12-18 months after admission.
Eighty-one patients with median age of 4.1 years completed the study. Agreement between tools was moderate (κ = 0.47). STAMP had a greater tendency to classify patients as high risk (12.3% vs. 2.5%). Both tools showed very weak correlation with height for age. All undernourished patients at the beginning and the end of the study were classified as medium or high risk by STAMP and STRONGkids (100% sensitivity), although specificity was below 50% in all cases. There were no differences in length of stay based on nutritional risk with any of the tools.
STAMP and STRONGkids demonstrated moderate agreement, with high sensitivity but low specificity for the diagnosis of undernutrition. Further studies are required to analyze cost-effectiveness of these tools and nutritional interventions derived from them.
The family Sciaenidae comprises about 300 species. The black drum Pogonias cromis was the only valid species of the genus. Herein, Pogonias courbina Lacepède 1803 is redescribed based on ...morphological and molecular evidence and a neotype is designated. Pogonias courbina is distinguished by the following characters: the occurrence of characteristic thickening of the dorsal spines VII to XI in all specimens larger than 250 mm SL; all pterygiophores in the dorsal-fin laminar, thin; anal-fin pterygiophores slender excluded those of spines; lateral projections of gas bladder with few finger-like projections; genetic distance between both species 1%; exclusive occurrence of characters in six informative sites of COI (58 G; 214 G; 328 A; 331 A; 553C; 580 G). The method Automatic Barcode gap Discovery detected gaps in nucleotid distance congruent with the NJ, MP, and ML tree analysis. Also, advertisement calls are three times shorter in duration in P. courbina than in P. cromis. In addition, two monophyletic groups for P. cromis and P. courbina appear in trees obtained with different methodologies, emphasizing the absence of shared haplotypes. A gap of about 8000 km occurs in the distribution of both species along coastal areas of the Atlantic Ocean.
Deep neural networks are currently trained under data-parallel setups on high-performance computing (HPC) platforms, so that a replica of the full model is charged to each computational resource ...using non-overlapped subsets known as batches. Replicas combine the computed gradients to update their local copies at the end of each batch. However, differences in performance of resources assigned to replicas in current heterogeneous platforms induce waiting times when synchronously combining gradients, leading to an overall performance degradation. Albeit asynchronous communication of gradients has been proposed as an alternative, it suffers from the so-called staleness problem. This is due to the fact that the training in each replica is computed using a stale version of the parameters, which negatively impacts the accuracy of the resulting model. In this work, we study the application of well-known HPC static load balancing techniques to the distributed training of deep models. Our approach is assigning a different batch size to each replica, proportional to its relative computing capacity, hence minimizing the staleness problem. Our experimental results (obtained in the context of a remotely sensed hyperspectral image processing application) show that, while the classification accuracy is kept constant, the training time substantially decreases with respect to unbalanced training. This is illustrated using heterogeneous computing platforms, made up of CPUs and GPUs with different performance.
La formulación de problemas como actividad genuinamente matemática es una fuente inagotable de alternativas en el aula. Son muchos los autores que indican la importancia de esta práctica, así como ...instituciones como el National Council of Teaching of Mathematics. Pretendemos, a través de un estudio de caso, evidenciar las características del conocimiento movilizado por una maestra, al implementar una sesión de este tipo en 4 años de educación infantil, con énfasis en el conocimiento que usa para la planificación y puesta en práctica de la sesión. Para ello, utilizamos fragmentos de la grabación de la sesión de aula, acompañado de una entrevista posterior a la informante, con el objetivo de corroborar la información identificada durante el análisis de los datos extraídos de la sesión. El carácter específico matemático de esta actividad nos lleva a utilizar el modelo MTSK (Mathematics Teaching Specialized Knowledge) como referente para analizar el conocimiento especializado que una maestra de educación infantil moviliza durante una práctica de aula. Esta práctica se compone de dos tareas, ambas creadas y diseñadas por la maestra informante. Los resultados muestran aspectos relacionados con el MK (Mathematical Knowledge), pero, sobre todo, un predominio del PCK (Pedagogical Content Knowledge) evidenciándose, la importancia de este conocimiento en la etapa de educación infantil para implementar una sesión de formulación de problemas.
The mud flounder Paralichthys orbignyanus (Pleuronectiformes, Paralichthyidae) inhabits shallow waters of low salinities and mud bottoms in the temperate marine coastal regions of the Bonaerensean ...Ecoregion of the Argentinean Biogeographic Province in the south‐western Atlantic Ocean. Specimens of P. orbignyanus were collected from Lagoa dos Patos (LDP) (southern Brazil), Mar Chiquita (MCH) and Marisol (MAR) both located in Buenos Aires (Argentina), and San Antonio Oeste (SAO) in the San Matías Gulf, Rio Negro (Argentina). A fragment of the mitochondrial DNA of the Control Region and seven microsatellite loci were characterized. In the Control Region, P. orbignyanus showed high variability, low nucleotide diversity, mild population expansion and a coalescence time of 35,000 years before the present. Flounders provided evidence of a genetic structure between the sampling sites LDP, MCH, MAR vs. SAO. On the other hand, P. orbignyanus displayed a lower to moderate contemporary genetic structure among all samples except between LDP and MCH. With no evidence of isolation by distance, this analysis supports a model of limited gene flow that is likely to be associated with a consistent larvae retention in all sampling sites. In addition, the present connectivity is ascribed to a lower migration process from SAO in the San Matías Gulf congruent with the prevailing littoral drift.
The most common methods for root finding of polynomials are iterative. This type of methods shows some drawbacks, like the impossibility of parallelization, the unpredictable nature of the ...iterations, that prevents to search roots inside a pre-specified region of complex plane, and the moderated degree of the polynomials that they can handle. This work describes a recursive root finding method. It is based on the winding number of plane curves, that is related to the number of zeros of a polynomial in a plane region. By our previous work (García Zapata and Díaz Martín, 2014) we find the winding number at reasonable computational cost, so we can approximate the roots by recursive subdivision of the search region. This subdivision approach is parallelizable, with a known bound of the computational cost, and the search can be restrained, in contrast to the iterative methods. We use error returns to identify and avoid singular curves, adapting the subdivision to the roots. This allows us to handle high degree polynomials without resorting to the expensive multiprecision arithmetics of other recursive methods. A significant contribution is that we formally prove its correctness.
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