5,757 research outputs found
T.M. Glass: The audible language of flowers [Exhibition catalogue]
May 8 to August 18, 2019
Onsite Gallery
199 Richmond St. W.
Toronto, ON, M5V 0H
Improving the Statistical Qualities of Pseudo Random Number Generators
Pseudo random and true random sequence generators are important components in many scientific and technical fields, playing a fundamental role in the application of the Monte Carlo methods and stochastic simulation. Unfortunately, the quality of the sequences produced by these generators are not always ideal in terms of randomness for many applications. We present a new nonlinear filter design that improves the output sequences of common pseudo random generators in terms of statistical randomness. Taking inspiration from techniques employed in symmetric ciphers, it is based on four seed-dependent substitution boxes, an evolving internal state register, and the combination of different types of operations with the aim of diffusing nonrandom patterns in the input sequence. For statistical analysis we employ a custom initial battery of tests and well-regarded comprehensive packages such as TestU01 and PractRand. Analysis results show that our proposal achieves excellent randomness characteristics and can even transform nonrandom sources (such as a simple counter generator) into perfectly usable pseudo random sequences. Furthermore, performance is excellent while storage consumption is moderate, enabling its implementation in embedded or low power computational platforms.This research was funded by the Spanish Ministry of Science, Innovation and Universities (MCIU), the State Research Agency (AEI), and the European Regional Development Fund (ERDF) under project RTI2018-097263-B-I00 (ACTIS)
Vacuum polarization around stars: nonlocal approximation
We compute the vacuum polarization associated with quantum massless fields
around stars with spherical symmetry. The nonlocal contribution to the vacuum
polarization is dominant in the weak field limit, and induces quantum
corrections to the exterior metric that depend on the inner structure of the
star. It also violates the null energy conditions. We argue that similar
results also hold in the low energy limit of quantum gravity. Previous
calculations of the vacuum polarization in spherically symmetric spacetimes,
based on local approximations, are not adequate for newtonian stars.Comment: 8 pages, no figure
Complicaciones a corto plazo de la artroplastia total primaria de cadera
Objetivos: Se pretende analizar las principales complicaciones a corto plazo (seis semanas) tras la Artroplastia total primaria de cadera. ;aterial y métodos: Se revisaron todos los pacientes a los que se realizó artroplastia total de cadera durante el año 2003. Las variables estudiadas fueron el índice de luxaciones, sangrado, infección, fracturas periprotésicas, complicaciones vásculo-nerviosas y mortalidad. Resultados: Obtuvimos una tasa del 4,4% de luxaciones; 1,7% de trombosis venosa profunda con un 0,87% de embolismo pulmonar, 1,7% de infecciones superficiales sin casos de infección profunda. El 14,9% de los casos necesitaron una transfusión postquirúrgica. Intraoperatoriamente observamos apertura del cálcar en el 3,5%, y fracturas periprotésicas postoperatorias en el 0,87%. No registramos complicaciones neurológicas ni mortalidad en estas primeras seis semanas del estudio. Conclusiones: La complicación más frecuente es la luxación, fundamentalmente en los casos secundarios a fractura. La trombosis venosa profunda, a èsar de la profilaxis, continúa siendo una complicación frecuente.Objectives: Our purpose was to analyze the main
early complications (six weeks) after primary total hip arthroplasty. Materials and Methods: All patients who had undergone primary total hip replacement during 2003 were reviewed. The studied outcomes were the rates of dislocation,
blood loss, infection, periprosthetic fractures, neural and
vascular complications, and mortality. Results: Our rates
were 4,4% for hip dislocation, 1,7% for deep vein thrombosis
with 0,87% for pulmonary embolism, 1,7% for wound infection
without cases of deep infection. 14,9% of the patients needed
postoperative transfusion. We reported 3,5% fractures of the
calcar during surgery and 0,87% of postoperative periprosthetic fractures. We didn ́t reported any neural complications
or mortality within six weeks postoperatively. Conclusions:
The most frequent complication is dislocation, mainly in
cases whose underlying diagnose was hip fracture. Although
prophylaxis is done, deep vein thrombosis goes on being a
frequent complication
Sciatic Nerve Cut and Repair Using Fibrin Glue in Adult Mice
Peripheral nerve injury (PNI) is an excellent model for studying neural responses to injury and elucidating the mechanisms that can facilitate axon regeneration. As such, several animal models have been employed to study regenerative mechanisms after PNI, including Aplysia, zebrafish, rabbits, cats and rodents. This protocol describes how to perform a sciatic nerve injury and repair in mice, one of the most frequently used models to study mechanisms that facilitate recovery after PNI, and that takes advantage of the availability of many genetic models. In this protocol, we describe a method for using fibrin glue to secure the proximal and distal stumps of an injured nerve in close alignment. This method facilitates the alignment of nerve stumps, which aids in regeneration of both sensory and motor axons and allows successful reconnection with peripheral targets
Valoración reproductiva de toros jóvenes de testaje de raza Parda de montaña
raza Parda de montañaPublishe
Business information architecture for successful project implementation based on sentiment analysis in the tourist sector
In the today's market, there is a wide range of failed IT projects in specialized small and medium-sized companies because of poor control in the gap between the business and its vision. In other words, acquired goods are not being sold, a scenario which is very common in tourism retail companies. These companies buy a number of travel packages from big companies and due to lack of demand for these packages, they expire, becoming an expense, rather than an investment. To solve this problem, we propose to detect the problems that limit a company by re-engineering the processes, enabling the implementation of a business architecture based on sentimental analysis, allowing small and medium-sized tourism enterprises (SMEs) to make better decisions and analyze the information that most possess, without knowing how to exploit it. In addition, a case study was applied using a real company, comparing data before and after using the proposed model in order to validate feasibility of the applied model.This work has been partially funded by the following projects of the Spanish Ministry of Science, Innovation and Universities GROMA (MTM2015-63710-P), MODAS-IN (reference: RTI2018-094269-B-I00), PPI (RTC-2015-3580-7) and UNIKO (RTC-2015-3521-7), and the “methaodos.org” research group at URJC
Genetic Targeting of Adult Renshaw Cells Using a Calbindin 1 Destabilized Cre Allele for Intersection With Parvalbumin or Engrailed1
Renshaw cells (RCs) are one of the most studied spinal interneurons; however, their roles in motor control remain enigmatic in part due to the lack of experimental models to interfere with RC function, specifically in adults. To overcome this limitation, we leveraged the distinct temporal regulation of Calbindin (Calb1) expression in RCs to create genetic models for timed RC manipulation. We used a Calb1 allele expressing a destabilized Cre (dgCre) theoretically active only upon trimethoprim (TMP) administration. TMP timing and dose influenced RC targeting efficiency, which was highest within the first three postnatal weeks, but specificity was low with many other spinal neurons also targeted. In addition, dgCre showed TMP-independent activity resulting in spontaneous recombination events that accumulated with age. Combining Calb1-dgCre with Parvalbumin (Pvalb) or Engrailed1 (En1) Flpo alleles in dual conditional systems increased cellular and timing specificity. Under optimal conditions, Calb1-dgCre/Pvalb-Flpo mice targeted 90% of RCs and few dorsal horn neurons; Calb1-dgCre/En1-Flpo mice showed higher specificity, but only a maximum of 70% of RCs targeted. Both models targeted neurons throughout the brain. Restricted spinal expression was obtained by injecting intraspinally AAVs carrying dual conditional genes. These results describe the first models to genetically target RCs bypassing development
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