187 research outputs found
Estudio de las variedades de olivo cultivadas en España
Estudio realizado por el Departamento de Pomología de la E.T.S. de Ingenieros Agrónomos de la Universidad de Córdoba, en el que se pretende realizar la prospección de los cultivares autóctonos de las diferentes zonas oleícolas de España, identificar las variedades localizadas, definir sus áreas de difusión y recopilar la información local existente sobre sus características agronómicas y tecnológicas; y, por último, introducir en colección los cultivares considerados diferentes
Generalized modified slash Birnbaum–Saunders distribution
In this paper, a generalization of the modified slash Birnbaum-Saunders (BS) distribution is introduced. The model is defined by using the stochastic representation of the BS distribution, where the standard normal distribution is replaced by a symmetric distribution proposed by Reyes et al. It is
proved that this new distribution is able to model more kurtosis than other extensions of BS previously proposed in the literature. Closed expressions are given for the pdf (probability density functio), along with their moments, skewness and kurtosis coefficients. Inference carried out is based on
modified moments method and maximum likelihood (ML). To obtain ML estimates, two approaches are considered: Newton-Raphson and EM-algorithm. Applications reveal that it has potential for doing well in real problems
Síndrome de las Piernas Inquietas en pacientes con talasemia minor
El Síndrome de Piernas Inquietas es un trastorno neurológico
incapacitante, de causa desconocida y poco diagnosticada. La incidencia en los
últimos años está en aumento con una prevalencia entre el 2-10%. Se ha descrito
relación con otras enfermedades como la celiaquía, la artritis reumatoide, la
fibromialgia, pero la asociación más frecuente se establece con pacientes que
presentan déficit de hierro y también de otras anemias no ferropénicas como la
anemia falciforme (discusión). El objetivo consiste en determinar la prevalencia y severidad del Síndrome de Piernas
Inquietas en pacientes diagnosticados de talasemia minor y comparar la
prevalencia obtenida en el estudio con la literatura revisada.Restless Legs Syndrome is a disabling neurological disorder of
unknown and underdiagnosed cause. The incidence in the last years is increasing
with prevalence between 2-10%. A relationship has been described with other
illnesses such as celiac disease, rheumatoid arthritis, fibromyalgia; but the most
frequent association is established with patients who present iron deficiency and
also other non-iron deficiency anemia, such as sickle cell anemia. The objective is to determine the prevalence and severity of Restless Legs Syndrome
in patients diagnosed with thalassemia minor and compare the prevalence obtained
in the study, with the literature reviewed.Medicin
Simulador de negocios Capstone: Estrategia competitiva de Ferris para obtención del primer lugar
El presente trabajo muestra un análisis de las decisiones tomadas en el simulador de negocios Capstone durante un periodo de ocho años por el equipo directivo que representó a la empresa Ferris.ITESO, A. C
Scale Mixture of Rayleigh Distribution
In this paper, the scale mixture of Rayleigh (SMR) distribution is introduced. It is proven that this new model, initially defined as the quotient of two independent random variables, can be expressed as a scale mixture of a Rayleigh and a particular Generalized Gamma distribution. Closed expressions are obtained for its pdf, cdf, moments, asymmetry and kurtosis coefficients. Its lifetime analysis, properties and Rényi entropy are studied. Inference based on moments and maximum likelihood (ML) is proposed. An Expectation-Maximization (EM) algorithm is implemented to estimate the parameters via ML. This algorithm is also used in a simulation study, which illustrates the good performance of our proposal. Two real datasets are considered in which it is shown that the SMR model provides a good fit and it is more flexible, especially as for kurtosis, than other competitor models, such as the slashed Rayleigh distribution
Centennial olive trees as a reservoir of genetic diversity
Background and AimsGenetic characterization and phylogenetic analysis of the oldest trees could be a powerful tool both for germplasm collection and for understanding the earliest origins of clonally propagated fruit crops. The olive tree (Olea europaea L.) is a suitable model to study the origin of cultivars due to its long lifespan, resulting in the existence of both centennial and millennial trees across the Mediterranean Basin.MethodsThe genetic identity and diversity as well as the phylogenetic relationships among the oldest wild and cultivated olives of southern Spain were evaluated by analysing simple sequence repeat markers. Samples from both the canopy and the roots of each tree were analysed to distinguish which trees were self-rooted and which were grafted. The ancient olives were also put into chronological order to infer the antiquity of traditional olive cultivars.Key ResultsOnly 9·6 % out of 104 a priori cultivated ancient genotypes matched current olive cultivars. The percentage of unidentified genotypes was higher among the oldest olives, which could be because they belong to ancient unknown cultivars or because of possible intra-cultivar variability. Comparing the observed patterns of genetic variation made it possible to distinguish which trees were grafted onto putative wild olives.ConclusionsThis study of ancient olives has been fruitful both for germplasm collection and for enlarging our knowledge about olive domestication. The findings suggest that grafting pre-existing wild olives with olive cultivars was linked to the beginnings of olive growing. Additionally, the low number of genotypes identified in current cultivars points out that the ancient olives from southern Spain constitute a priceless reservoir of genetic diversity
Hedgerow olive orchards: reality or utopia?
Actualmente las plantaciones de olivar
tienen unas densidades que no suelen superar
los 330 olivos por hectárea. El mayor
coste su cultivo se produce en la recolección,
donde se necesita una gran cantidad de
mano de obra. Recientemente ha surgido un
nuevo tipo de plantaciones cuyas densidades
se acercan a las 2000 plantas por hectárea y
donde los olivos se disponen en setos continuos
separados unos 3,5 m.
La mayor ventaja de este tipo de plantaciones
es su recolección totalmente mecanizada,
mediante máquinas cabalgadoras que
pasan por encima de los setos, en un sistema
muy parecido al usado en la vid. Además,
estas plantaciones son de muy temprana entrada
en producción y muy productivas, al
menos en los primeros años. La variedad
que se utiliza, casi en exclusiva, para este tipo
de plantaciones es ‘Arbequina’.
En el presente trabajo se describen los resultados
de un ensayo comparativo de variedades
que se estableció en el año 2000 y
del que se han recogido ya 4 cosechas. Este
ensayo incluye las variedades ‘Arbequina’,
‘Arbequina i-18’, ‘Arbosana’, ‘Koroneiki’,
‘Fs-17’ y ‘UC 2-35’. De ellas, ‘Arbequina’
y ‘Arbosana’ han sido las más productivas y
‘UC 2-35’ la menos vigorosa de las ensayadas. También se describen los resultados de
un ensayo comparativo de densidades desde
754 a 2580 plantas/ha que fue establecido
en el año 1999. Hasta ahora, la densidad
más productiva parece ser la de 2000 plantas/
ha. Habrá que esperar a los próximos
años para tener resultados más definitivos
sobre éstos ensayos ya que es de esperar que
a partir de ahora es cuando aparezcan los
problemas relacionados con la competencia
entre árboles.
En conclusion, en un escenario donde las
ayudas de la Unión Europea van a ir disminuyendo
progresivamente, y donde la mano
de obra es cada vez más difícil de encontrar,
la capacidad real de este tipo de plantaciones
de ser rentables a largo plazo determinará
el futuro éxito de las mismas.Nowadays, olive orchards have a densities
not higher than 330 trees/ha. The major
cost correspond to harvest operations, which
is very labour demanding. Recently, a new
type of olive plantations with densities
around 2.000 tress/ha has appeared.
The major advantage of this type of plantations
is their totally mechanised harvest,
by vineyards straddle-harvesting machines.These plantations have a very early bearing
and very productive, at least in the first
years. The most common cultivar used is
‘Arbequina’.
In the present work, data of the first four
harvest of a variety comparative trial are reported.
This trial include ‘Arbequina’, ‘Arbequina
i-18’, ‘Arbosana’, ‘Koroneiki’, ‘Fs-
17’ y ‘UC 2-35’ cultivars. From the ‘Arbequina’
and ‘Arbosana’ had been the most
productive and ‘UC 2-35’ the less vigorous.
Results of a trial testing densities between
780 and 2580 trees/ha is also described. Up
to now, the higher densities have been the
most productive ones. However, more definitive
results can be obtained in the coming
years, when problems of competence
among trees started to appear.
In summary, as in the near future is expected
that the subsides from the EU are going
to be greatly reduced and the labour for
harvesting is difficult to find, the ability to
this type of plantations to be profitable at
long term will determine their success
Especies comunes del bosque seco en el campus de la Universidad del Magdalena
Esta cartilla se convierte en una herramienta para la divulgación de la biodiversidad de la flora y fauna asociada a un relicto de bosque seco tropical dentro de una matriz urbana ubicada en Santa Marta, Colombia, y presenta ilustraciones de las 50 especies más representativas de este ecosistema
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