2,227 research outputs found
Use of Molecular Markers to Assist the Development of Inbred Lines under Open Field Conditions: the Case of Criollo Peppers (Capsicum annuum L.) from Mexico
[EN] Chile peppers are one of the most important crops in Mexico and a plethora of ecotypes can be found there. Most of them are ancient open-pollinated (OP) landraces selected by farmers for uniform phenotype but with an inherent level of genetic diversity, called criollos. In this work 15 pepper accessions, encompassing 2 criollo lines, their open-pollinated progenies, and 5 controls, were characterized with a set of 36 IPGRI descriptors and 23 SSR markers to assess the effect of open pollination in the inbreeding process. Heterozygosity levels were comprised between 12 and 47% in the progenies, which were similar or lower than those values from parent plants and similar or higher than control cultivars. Also, both progenies and parents showed similar levels of agronomic and morphological uniformity. Our results suggest that this OP program is efficient in terms of reaching enough agronomic uniformity in criollo Ancho peppers while preserving certain genetic diversity to confer adaptation to climate change.This work was partly financed by projects INIA RTA2013-00022-C02-02 and RTA2014-00041-C02-02, funded by Instituto Nacional Investigaciones Agrarias (Spain), FEDER funds. Also, Mexican authors thank CONACYT for financing the stay of Gustavo Chavez-Gonzalez in Spain, as well as the Programa Integral de Fortalecimiento Institucional (PIFI) de la UA de Aguascalientes (SEP-Mexico).Pereira-Días, L.; Chavez-Gonzalez, G.; Bracho Gil, M.; Fita, A.; Vilanova Navarro, S.; Luna-Ruiz, J.; Perez-Cabrera, L.... (2017). Use of Molecular Markers to Assist the Development of Inbred Lines under Open Field Conditions: the Case of Criollo Peppers (Capsicum annuum L.) from Mexico. Notulae Botanicae Horti Agrobotanici Cluj-Napoca. 45(2):365-368. https://doi.org/10.15835/nbha45210940S36536845
Five supernova survey galaxies in the southern hemisphere. I. Optical and near-infrared database
The determination of the supernova (SN) rate is based not only on the number
of detected events, but also on the properties of the parent galaxy population.
This is the first paper of a series aimed at obtaining new, refined, SN rates
from a set of five SN surveys, by making use of a joint analysis of
near-infrared (NIR) data. We describe the properties of the 3838 galaxies that
were monitored for SNe events, including newly determined morphologies and
their DENIS and POSS-II/UKST I, 2MASS and DENIS J and Ks and 2MASS H
magnitudes. We have compared 2MASS, DENIS and POSS-II/UKST IJK magnitudes in
order to find possible systematic photometric shifts in the measurements. The
DENIS and POSS-II/UKST I band magnitudes show large discrepancies (mean
absolute difference of 0.4 mag), mostly due to different spectral responses of
the two instruments, with an important contribution (0.33 mag rms) from the
large uncertainties in the photometric calibration of the POSS-II and UKST
photographic plates. In the other wavebands, the limiting near infrared
magnitude, morphology and inclination of the galaxies are the most influential
factors which affect the determination of photometry of the galaxies.
Nevertheless, no significant systematic differences have been found between of
any pair of NIR magnitude measurements, except for a few percent of galaxies
showing large discrepancies. This allows us to combine DENIS and 2MASS data for
the J and Ks filters.Comment: 17 pages, 3 figures, 5 tables, published in Astrophysics, Vol. 52,
No. 1, 2009 (English translation of Astrofizika
Transit Photometry as an Exoplanet Discovery Method
Photometry with the transit method has arguably been the most successful
exoplanet discovery method to date. A short overview about the rise of that
method to its present status is given. The method's strength is the rich set of
parameters that can be obtained from transiting planets, in particular in
combination with radial velocity observations; the basic principles of these
parameters are given. The method has however also drawbacks, which are the low
probability that transits appear in randomly oriented planet systems, and the
presence of astrophysical phenomena that may mimic transits and give rise to
false detection positives. In the second part we outline the main factors that
determine the design of transit surveys, such as the size of the survey sample,
the temporal coverage, the detection precision, the sample brightness and the
methods to extract transit events from observed light curves. Lastly, an
overview over past, current and future transit surveys is given. For these
surveys we indicate their basic instrument configuration and their planet
catch, including the ranges of planet sizes and stellar magnitudes that were
encountered. Current and future transit detection experiments concentrate
primarily on bright or special targets, and we expect that the transit method
remains a principal driver of exoplanet science, through new discoveries to be
made and through the development of new generations of instruments.Comment: Review chapte
Balancing with Vibration: A Prelude for “Drift and Act” Balance Control
Stick balancing at the fingertip is a powerful paradigm for the study of the control of human balance. Here we show that the mean stick balancing time is increased by about two-fold when a subject stands on a vibrating platform that produces vertical vibrations at the fingertip (0.001 m, 15–50 Hz). High speed motion capture measurements in three dimensions demonstrate that vibration does not shorten the neural latency for stick balancing or change the distribution of the changes in speed made by the fingertip during stick balancing, but does decrease the amplitude of the fluctuations in the relative positions of the fingertip and the tip of the stick in the horizontal plane, A(x,y). The findings are interpreted in terms of a time-delayed “drift and act” control mechanism in which controlling movements are made only when controlled variables exceed a threshold, i.e. the stick survival time measures the time to cross a threshold. The amplitude of the oscillations produced by this mechanism can be decreased by parametric excitation. It is shown that a plot of the logarithm of the vibration-induced increase in stick balancing skill, a measure of the mean first passage time, versus the standard deviation of the A(x,y) fluctuations, a measure of the distance to the threshold, is linear as expected for the times to cross a threshold in a stochastic dynamical system. These observations suggest that the balanced state represents a complex time–dependent state which is situated in a basin of attraction that is of the same order of size. The fact that vibration amplitude can benefit balance control raises the possibility of minimizing risk of falling through appropriate changes in the design of footwear and roughness of the walking surfaces
Biopsychosocial factors related to the length of hospital stay in older people
This study aimed to know what variables influence increased length of hospital stay. A descriptive, cross-sectional study was conducted through an integrated geriatric assessment of 81 people over 65 years of age, admitted to a tertiary acute care hospital. Data were collected through the Pfeiffer Scale, Barthel Index, Goldberg Questionnaire, Family APGAR and Gijón Scale. The length of hospital stay increased in people over 80 years, people living alone or in a retirement home, patients with great physical dependence and those with a risk or problem of social exclusion. The most influential variable for longer hospitalization was cognitive impairment (pEste estudio tuvo como objetivo conocer qué variables influyen en el aumento de la duración de la estancia hospitalaria. Se trata de un estudio descriptivo transversal en el que se realizó una Valoración Geriátrica Integral a 81 personas mayores de 65 años de edad que ingresaron en un hospital de agudos de tercer nivel. Para ello, los datos fueron recogidos por medio de la Escala de Pfeiffer, el Índice de Barthel, el Cuestionario de Goldberg, el APGAR familiar y la Escala de Gijón. Se observó un aumento de la duración de la estancia hospitalaria entre los mayores de 80 años, las personas que vivían solas o en una residencia geriátrica, los pacientes que presentaban gran dependencia física y también, entre quienes tenían un riesgo o problema de exclusión social. La variable que más influyó en la mayor duración de la hospitalización fue el deterioro cognitivo (pEste estudo teve como objetivo conhecer quais as variáveis que influenciam o aumento do tempo de internação hospitalar. Trata-se de estudo descritivo e transversal, conduzido mediante ampla avaliação geriátrica de 81 pessoas com mais de 65 anos, internadas em hospital terciário de cuidados agudos. Os dados foram coletados através da Escala Pfeiffer, Índice de Barthel, Questionário de Goldberg, Apgar da Família e Escala de Gijón. Observou-se aumento no tempo de internação entre pessoas com mais de 80 anos, pessoas que vivem sozinhas ou em lar de idosos, pacientes que tinham grande dependência física, e entre aqueles com algum risco ou problema de exclusão social. A variável mais influente, para a maior duração da hospitalização, foi a deterioração cognitiva (p<0,05), em comparaç��o à maior colaboração do paciente sem essa condição ou ao seu desejo de superar a fase aguda da patologia que levou à internação hospitalar
The Intermediate Scale MSSM, the Higgs Mass and F-theory Unification
Even if SUSY is not present at the Electro-Weak scale, string theory suggests
its presence at some scale M_{SS} below the string scale M_s to guarantee the
absence of tachyons. We explore the possible value of M_{SS} consistent with
gauge coupling unification and known sources of SUSY breaking in string theory.
Within F-theory SU(5) unification these two requirements fix M_{SS} ~ 5 x
10^{10} GeV at an intermediate scale and a unification scale M_c ~ 3 x 10^{14}
GeV. As a direct consequence one also predicts the vanishing of the quartic
Higgs SM self-coupling at M_{SS} ~10^{11} GeV. This is tantalizingly consistent
with recent LHC hints of a Higgs mass in the region 124-126 GeV. With such a
low unification scale M_c ~ 3 x 10^{14} GeV one may worry about too fast proton
decay via dimension 6 operators. However in the F-theory GUT context SU(5) is
broken to the SM via hypercharge flux. We show that this hypercharge flux
deforms the SM fermion wave functions leading to a suppression, avoiding in
this way the strong experimental proton decay constraints. In these
constructions there is generically an axion with a scale of size f_a ~
M_c/(4\pi)^2 ~ 10^{12} GeV which could solve the strong CP problem and provide
for the observed dark matter. The prize to pay for these attractive features is
to assume that the hierarchy problem is solved due to anthropic selection in a
string landscape.Comment: 48 pages, 8 figures. v3: further minor correction
Insulin-Producing Cells Generated from Dedifferentiated Human Pancreatic Beta Cells Expanded In Vitro
Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, attempts at expanding human islet cells in tissue culture result in loss of beta-cell phenotype. Using a lineage-tracing approach we provided evidence for massive proliferation of beta-cell-derived (BCD) cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT). Epigenetic analyses indicate that key beta-cell genes maintain open chromatin structure in expanded BCD cells, although they are not transcribed. Here we investigated whether BCD cells can be redifferentiated into beta-like cells.Redifferentiation conditions were screened by following activation of an insulin-DsRed2 reporter gene. Redifferentiated cells were characterized for gene expression, insulin content and secretion assays, and presence of secretory vesicles by electron microscopy. BCD cells were induced to redifferentiate by a combination of soluble factors. The redifferentiated cells expressed beta-cell genes, stored insulin in typical secretory vesicles, and released it in response to glucose. The redifferentiation process involved mesenchymal-epithelial transition, as judged by changes in gene expression. Moreover, inhibition of the EMT effector SLUG (SNAI2) using shRNA resulted in stimulation of redifferentiation. Lineage-traced cells also gave rise at a low rate to cells expressing other islet hormones, suggesting transition of BCD cells through an islet progenitor-like stage during redifferentiation.These findings demonstrate for the first time that expanded dedifferentiated beta cells can be induced to redifferentiate in culture. The findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug screening
Measuring changes in Schlemm’s canal and trabecular meshwork in different accommodation states in myopia children: an observational study
Abstract
Purpose: Studies were designed to evaluate changes in the size of the Schlemm's Canal (SC) and trabecular meshwork(TM) during accommodation stimuli and cycloplegia states in myopic children.
Methods: 34 children were enrolled. A -6D accommodation stimulus was achieved by looking at an optotype through a mirror. Cycloplegia state was induced with 1% tropicamide. Two states were confirmed by measuring the central lens thickness(CLT), the anterior chamber depth and the pupil diameter. The size of the Schlemm's Canal (SC) and Trabecular Meshwork(TM) was measured using swept-source optical coherence tomography. And the associations between the change of the SC and the CLT were analyzed.
Results: When compared with the relaxation state, under -6D accommodation stimuli, the size of SC increased significantly: the SC area (SCA) amplified from 6371±2517μm2 to 7824±2727 μm2; the SC length (SCL) from 249±10 μm to 295±12 μm, and SC width (SCW) from 27±9 μm to 31±8 μm. Under cycloplegia state, the SCA reduced to 5009±2028 μm2; the SCL to 212±μm and the SCW to 22±5 μm. In addition, the changed areas of SCA (r=0. 35; P=0.0007), SCL (r=0. 251; P=0.0172), and SCW (r=0. 253; P=0.016) were significantly correlated with the change in CLT. However, the size of TM did not change substantially when compared with the relaxation state. Only the TM length (TML) increased from 562±45μm to 587±47μm after -6D accommodation stimulus.
Conclusion: SC size enlarges after -6D accommodation stimuli and shrinks under cycloplegia. However, for TM, only the TM length increase under accommodation stimulus state.
KEYWORDS: Schlemm’s Canal, Trabecular Meshwork, accommodatio
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