1,097 research outputs found
Ventajas y desventajas del an?lisis de un dise?o de medidas repetidas mediante an?lisis de varianza univariado, multivariado y modelos lineales mixtos
89 p. Recurso Electr?nicoLa presente tesis describe, sustenta y analiza las Medidas Repetidas aplicando an?lisis
univariado, an?lisis multivariado y modelos lineales mixtos con el objetivo de ver las
ventajas y desventajas de dichos enfoques. La metodolog?a de la investigaci?n utilizada
para el desarrollo puede considerarse como exploratoria y descriptiva por cuanto en todo
el proceso se indaga los individuos que hacen parte del estudio y sus mediciones a trav?s
del tiempo y/o espacio.
Para los diferentes an?lisis se us? un experimento realizado a 17 reses j?venes cuyo fin
era medir el crecimiento de las estas al proporcionarles dos tipos de tratamientos
distintos por 12 semanas tomados del libro de Biostatistics for animal science.(2004).
Finalmente se mostr? que el mejor enfoque result? ser el de los modelos mixtos.
Palabras claves: modelo Lineal general, Modelo Lineal mixto, medidas repetidasThe thesis describes, supports and analyzes Repeated Measures through Mixed Linear
Models. This research can be considered as exploratory and descriptive because we
investigate in the measurements through time and / or space. the individuals who are part
of our study, under specific conditions to be able to apply the mixed linear model; An
experiment was carried out on 17 young cattle, the purpose was to measure the cattle?s
growth by providing two different treatments for 12 weeks taken from the book
Biostatistics for animal science.
Keywords: General Linear Model, Mixed Linear Model, repeated measures
Mesoscopic atomic entanglement for precision measurements beyond the standard quantum limit
Squeezing of quantum fluctuations by means of entanglement is a well
recognized goal in the field of quantum information science and precision
measurements. In particular, squeezing the fluctuations via entanglement
between two-level atoms can improve the precision of sensing, clocks,
metrology, and spectroscopy. Here, we demonstrate 3.4 dB of metrologically
relevant squeezing and entanglement for ~ 10^5 cold cesium atoms via a quantum
nondemolition (QND) measurement on the atom clock levels. We show that there is
an optimal degree of decoherence induced by the quantum measurement which
maximizes the generated entanglement. A two-color QND scheme used in this paper
is shown to have a number of advantages for entanglement generation as compared
to a single color QND measurement.Comment: 6 pages+suppl, PNAS forma
POSSIBILITY OF GENETIC IMPROVEMENT OF PIGEONPEA (CAJANUS CAJAN (L.) MILLSP.) UTILIZING WILD GENE SOURCES
Análisis de la heurÃstica en la contratación empresarial a través de una cartera de derivados reales
Departing from the notion that labour legislation should be founded in the generation of job stability a model for recruitment is presented in which the employer is likened to the holder of an investment portfolio containing two real derivatives – swap or the option of sale. This model allows us on one hand to analyze sensitivity to the variables that are at play in an employment contract and, on the other, look at the effects that the most recent reforms in Spanish labour laws have had on contracting decisions made by employers. The results are clear: social security benefits are shown to be the most sensitive variable on the work contract, and applying the changes proposed in the latest labour reforms, this effect is upheld. The study concludes that reducing the costs of dismissal does not increase the likelihood of employers’ taking on new staff.Dada la situación actual y partiendo del supuesto que como herramienta para una correcta polÃtica de empleo la legislación laboral debe sentar las bases sólidas para que en el momento de recuperación económica se generen puestos de trabajo estables, se presenta un modelo de simulación de contratación que nos va a permitir un análisis de sensibilidad de las distintas variables a tener en cuenta en una regulación del mercado laboral. El modelo consiste en asimilar el comportamiento del empresario al del propietario de una cartera de inversión compuesta por dos derivados reales, un swap y una opción de venta americana. Este modelo nos permite, por un lado, hacer un análisis de sensibilidad de las diferentes variables que intervienen en la contratación, y, por otro lado, analizar los efectos que la última reforma laboral española tiene sobre la decisión de contratar del empresario. Los resultados son claros, la variable que más sensibilidad presenta sobre la contratación es la cuota patronal de la seguridad social, y aplicando los cambios propuestos en esta última reforma laboral, se concretan estos efectos y también se concluye que la reducción de los costes de despido no acelera la decisión de contratar.Dada a situação atual e partindo do suposto que como ferramenta para uma correta polÃtica de emprego, a legislação laboral deve instituir as bases sólidas para que, no momento da recuperação econômica, se gerem postos de trabalho estáveis, se apresentem um modelo de simulação de contratação que nos permitirá uma análise de sensibilidade das diferentes variáveis a considerar em uma regulação do mercado laboral. O modelo consiste em assimilar o comportamento do empresário ao do proprietário de uma carteira de investimento composto por dois derivados reais, um swap e uma opção de venda americana. Esse modelo nos permite, por um lado, fazer uma análise de sensibilidade das diferentes variáveis que intervêm na contratação e, por outro lado, analisar os efeitos que a última reforma laboral espanhola tem sobre a decisão de contratar do empresário. Os resultados são claros, a variável que mais sensibilidade apresenta sobre a contratação é a cota patronal da previdência social e aplicando as mudanças propostas nesta última reforma laboral, concretizam-se esses efeitos e também se conclui que a redução dos custos de demissão não acelera a decisão de contrata
Selecci\uf3n de aislamientos de hongos entomopat\uf3genos para el control de huevos de la polilla del tomate, Tuta absoluta Meyrick (Lepidoptera: gelechiidae)
A pathogenicity study of 64 Metarhizium anisopliae var. anisopliae
and 70 Beauveria bassiana isolates against tomato moth Tuta absoluta
eggs, was carried out under laboratory conditions. The first
evaluation was accomplished by spraying suspensions of 107 conidias
mL-1 of each isolate directly on eggs, through a Potter tower.
Mortality and conidia production on the eggs were significantly higher
with the isolates M. anisopliae Qu-M558 and B. bassiana Qu-B911,
Qu-B912 and Qu-B928. These isolates were newly evaluated using
increasing conidia concentrations (0 to 108 conidia mL-1) of each of
the five selected isolates. The isolates Qu-B912 and Qu-M558 produced
the highest mortality percentages based on the area under mortality
progress curve for each concentration, 80 and 60%, respectively.Se realiz\uf3 un estudio en laboratorio sobre la patogenicidad de 64
aislamientos de Metarhizium anisopliae var. anisopliae y 70 de
Beauveria bassiana , en huevos de polilla del tomate Tuta absoluta .
La primera evaluaci\uf3n se realiz\uf3 por aplicaci\uf3n directa
de suspensiones de 107 conidias mL-1 para cada aislamiento, con el
sistema de pulverizaci\uf3n de la torre de Potter. La mortalidad y
esporulaci\uf3n sobre huevos fueron significativamente mayores con
los aislamientos M. anisopliae Qu-M558 y B. bassiana Qu-B911, Qu-B912 y
Qu-B928. Estos aislamientos fueron evaluados nuevamente en suspensiones
crecientes de 0 a 108 conidias mL-1. Los aislamientos Qu-M558 y
Qu-B912, produjeron los mayores porcentajes de mortalidad sobre la base
del c\ue1lculo del \ue1rea bajo la curva del progreso de mortalidad
de huevos, 80 y 60%, respectivamente
The AMANDA Neutrino Telescope and the Indirect Search for Dark Matter
With an effective telescope area of order 10^4 m^2, a threshold of ~50 GeV
and a pointing accuracy of 2.5 degrees, the AMANDA detector represents the
first of a new generation of high energy neutrino telescopes, reaching a scale
envisaged over 25 years ago. We describe its performance, focussing on the
capability to detect halo dark matter particles via their annihilation into
neutrinos.Comment: Latex2.09, 16 pages, uses epsf.sty to place 15 postscript figures.
Talk presented at the 3rd International Symposium on Sources and Detection of
Dark Matter in the Universe (DM98), Santa Monica, California, Feb. 199
Presbyvestibulopathy, Comorbidities, and Perception of Disability: A Cross-Sectional Study
Objective: To assess the perception of disability in patients with presbyvestibulopathy and to determine the factors (demographic, balance test scores, and comorbidities) that determine higher levels of disability. Material and Methods: This was a cross-sectional study conducted in a tertiary university hospital. There were 103 patients who fulfilled the diagnostic criteria for presbyvestibulopathy and were included. Dizziness Handicap Inventory (DHI) score was the main variable used to quantify disability. Influence on DHI score, sex, age, time of evolution, equilibriometric parameters (posturographic scores and timed up and go test), history of falls, comorbidities (high blood pressure, diabetes, and dyslipidemia), psychotropic drug use, tobacco or alcohol use, living environment (urban or rural), and active lifestyle were analyzed. Results: Most of the DHI scores showed a moderate (46 patients, 44.7%) or severe (39 participants, 37.9%) handicap. DHI scores were higher in women (59.8 vs. 36.1, p < 0.001), patients with obesity (58.92 vs. 48.68; p = 0.019), benzodiazepine (59.9 vs. 49.1, p = 0.008) or other psychotropic drug (60.7 vs. 49.2, p = 0.017) users, and fallers (57.1 vs. 47.3, p = 0.048). There was also a significant positive correlation between DHI score, time (Rho coefficient: 0.371, p < 0.001), and steps (Rho coefficient: 0.284, p = 0.004) used in the TUG and with the short FES-I questionnaire (a shortened version of the Falls Efficacy Scale-International) score (Rho coefficient: 0.695, p < 0.001). DHI scores were lower in alcohol consumers than in non-drinkers (46.6 vs. 56, p = 0.048). No significant correlation was found between DHI scores and age, time of evolution, posturographic scores, comorbidities, environment (rural or urban), or active lifestyle. Conclusion: Most patients with presbyvestibulopathy show an important subjective perception of disability in relation to their symptoms. This perception is substantially higher in women than in men. The most influential factors are difficulties in walking, fear of falling, and obesity. Unique Identifier: NCT03034655, www.clinicaltrials.gov
Modified Timed Up and Go Test for Tendency to Fall and Balance Assessment in Elderly Patients With Gait Instability
Objective: To compare the results from the modified Timed Up and Go Test (TUG) with posturographic variables, the subjective perception of disability due to gait instability, and the number of falls in a sample of the elderly population with imbalance, to confirm that the TUG Test is a useful clinical instrument to assess the tendency to fall in individuals of this age group. Materials and Methods: Cross-sectional study conducted in a tertiary university hospital, in 174 people aged 65 years or older with gait instability. Modified TUG Test was performed; time, step count and the need for support during the test were the analyzed variables. They were compared with the number of falls, Computerized Dynamic Posturography scores, and questionnaires scores (Dizziness Handicap Inventory and a shortened version of the Falls Efficacy Scale-International). Results: The average time to complete the TUG Test was 21.24 +/- 8.18 s, and the average step count was 27.36 +/- 7.93. One hundred two patients (58.6%) required no support to complete the test, whereas the other 72 (41.4%) used supports. The time taken to complete the Test was significantly related with having or not having fallen in the previous year, with the scores of the questionnaires, and with various parameters of dynamic posturography. A higher percentage of patients who took more than 15 s had fallen in the previous year than those who took up to 15 s to complete the test [P = 0.012; OR = 2.378; 95% CI (1.183, 4.780)]. No significant correlation was found between the step count and the number of falls in the previous year, with falling during the test or not, or with being a single or a frequent faller. No relation was found between the need for supports and the number of falls, with having or not having fallen in the previous year, or with being a single or frequent faller. Conclusion: The modified TUG Test is in relation with the presence or absence of falls. Time is the essential parameter for analyzing the risk of falling and the 15-s threshold is a good value to differentiate elderly patients at high risk of falling. Unique Identifier: NCT03034655, www.clinicaltrials.gov
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