5,252 research outputs found
Morphological variation of the labellum of Vanilla planifolia Andrews (Orchidaceae) in Oaxaca, Mexico
Infraspecific variation has transcendental ecological consequences for species adaptation to new niches. Estimating levels of variation is key for understanding the life history of a species, as well as for designing strategies for use and conservation. For this reason, the objective of this study was to characterize infra-specific morphological variation of the labellum of V. planifolia, of 122 flowers from 28 specimens from the state of Oaxaca and two specimens from Veracruz, Mexico. The labellum of each flower was dissected and analyzed by morphometry. Sixty variables were obtained and grouped into basal, middle and apical regions. An analysis of variance was performed considering the collections and the origin of each individual as sources of variation. Principal components and cluster analyses were also conducted. Differences in the 60 variables analyzed were highly significant among the collections. Among environments, 18 variables showed significant differences, which were situated in the lateral and middle lobes of the labellum. Thus, these structures were considered susceptible to environmental changes. The remaining 42 variables situated in the basal and middle regions of the labellum, which were fused to the edges of the floral column were not significantly different among environments. With the first three principal components, the model explained 73% of the total variation studied. Morphological variation of the flower labellum was represented by four morphotypes distributed in three environments.
Highlights
The evaluation of vanilla flowers wild does not allow to have the same number of treatments or repetitions, for the inaccessibility of the species.
Morphometric analysis of the labellum revealed infra-specific variation in the germplasm of Vanilla planifolia.
The features of the basal and middle regions of the labellum are the most informative in distinguishing the variation between vanilla specimens.Infraspecific variation has transcendental ecological consequences for species adaptation to new niches. Estimating levels of variation is key for understanding the life history of a species, as well as for designing strategies for use and conservation. For this reason, the objective of this study was to characterize infra-specific morphological variation of the labellum of V. planifolia, of 122 flowers from 28 specimens from the state of Oaxaca and two specimens from Veracruz, Mexico. The labellum of each flower was dissected and analyzed by morphometry. Sixty variables were obtained and grouped into basal, middle and apical regions. An analysis of variance was performed considering the collections and the origin of each individual as sources of variation. Principal components and cluster analyses were also conducted. Differences in the 60 variables analyzed were highly significant among the collections. Among environments, 18 variables showed significant differences, which were situated in the lateral and middle lobes of the labellum. Thus, these structures were considered susceptible to environmental changes. The remaining 42 variables situated in the basal and middle regions of the labellum, which were fused to the edges of the floral column were not significantly different among environments. With the first three principal components, the model explained 73% of the total variation studied. Morphological variation of the flower labellum was represented by four morphotypes distributed in three environments.
Highlights
The evaluation of vanilla flowers wild does not allow to have the same number of treatments or repetitions, for the inaccessibility of the species.
Morphometric analysis of the labellum revealed infra-specific variation in the germplasm of Vanilla planifolia.
The features of the basal and middle regions of the labellum are the most informative in distinguishing the variation between vanilla specimens
Study of the physical properties of soils through interpretation of aerial photographs
Final technical reportThe purpose of the research work proposed is the study of the physical
properties of the soils by means of the interpretation of aerial photographs.
This study is to be carried out in two years and thus it is not possible to
give definite conclusions at the end of the first year, although the results
we have obtained are highly satisfactory. In our opinion and after the experience
of the first year, the working problem of the study of the physical
properties of the soils through aerial photographs, can be examined from two
different aspects. The first of them could be called the "deductive" method
and consists in acquiring knowledge of the physical properties of the soils
by means of sucoessive interpretations of aerial photographs; through photointerpretation
we study the physical Geography of an area, its hydrographic
net, natural vegetation and .man-introduced cultivations, the forms of erosion
end the nature of the geological material, All these interpretations, together
with the clitmate, allow to "deduce" the nature of the soils of that area, as
all the pedological processes which the different geological materials have
undergone can be know perfectly well, which also shows the intensity of physical
and chemical desintegration of the materials that form the starting
point of soil formation.The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army through its European Research Office.Contract No. DA-91-591-EUC-2652 1st. April 1963 to 31th March
1964.N
Continuous Synthesis of Cu/ZnO/Al2O3 Nanoparticles in a Co-precipitation Reaction Using a Silicon Based Microfluidic Reactor
Distribution and salinity tolerance of the invasive isopod Synidotea laticauda in the Guadalquivir estuary (SW Spain): Field and laboratory observations
Trabajo presentado en ECSA 56 (Coastal systems in transition: From a 'natural' to an 'anthropogenically-modified' state), celebrado en Bremen del 4 al 7 de septiembre de 2016.The effects of the exotic species in native communities are unpredictable and ecological studies should be required for environmental management. In Europe, the exotic species Synidotea laticauda has been introduced in several estuaries but there was not any previous biological study about these non-native populations. The spatio-temporal field distribution of S. laticauda in the last 30 km of the Guadalquivir estuary (salinities 0 to 30) was assessed during 7 years (August 1997-June 2004) by sampling at each new moon with a mesh size net of 1 mm. Survival and osmoregulatory patterns of the species under different experimental salinity conditions were also estimated. This exotic species is a permanent resident of the estuary, with presence of juveniles and adults during most of the year, but showing maximum densities in the warmest period (summer to early autumn). Spatial patterns were closely related to the salinity gradient: the highest densities were observed between 10 and 30 of salinity, with a maximum at 20 (â isosmotic point). In fact, the isopod is a weak osmoregulator, which maintains the osmolality of the hemolymph partially independent of the medium osmolality (in a salinity range of 5 to 25). Moreover, survival experiments showed a high tolerance (mortality < 30%) to sudden salinity changes between 2 and 35 and virtually no mortality in salinities (15-25) close to the isosmotic point (20). Osmoregulatory and survival patterns were not dependent on sex but they seemed to be specific-dependent on salinity acclimation. Although it is a euryhaline species, its weak osmoregulatory capacity explains its salinity-dependent distribution pattern. Our results provide a framework to predict the distribution of this invasive species under sceneries of climate change and consequent freshwater scarcity.N
Transverse Load and Temperature Sensing Using Multiplexed Long-Period Fiber Gratings
The simultaneous measurement of transverse load and temperature using two long-period fiber gratings multiplexed in the wavelength domain is presented experimentally. For this, a mechanically induced long-period fiber grating (MI-LPFG) and a long-period fiber grating inscribed by a continuous-wave CO2 laser (CO2 LPFG) are connected in cascade. First, the transverse load and the temperature measurements were individually performed by the multiplexed long-period fiber gratings configuration. The MI-LPFG is subject to a transverse load variation from 0â2000 g with steps of 500 g, whereas the CO2 LPFG is unloaded and they are kept at room temperature. Similarly, the CO2 LPFG is subject to a temperature variation from 30 to 110 °C by increments of 20 °C, while the MI-LPFG with a constant transverse load of 2000 g is kept at room temperature. Subsequently, the simultaneous measurement of the transverse load and the temperature is performed by the multiplexed long-period fiber grating following the steps outlined above. According to the experimental results, the transverse load and temperature measurement present high repeatability for the individual and simultaneous process. Moreover, the multiplexed LPFGs exhibit low cladding-mode crosstalk of transverse load and temperature. The coarse wavelength-division multiplexing (CWDM) of long-period fiber gratings is an attractive alternative technique in optical fiber distributed sensing applications
Magnetic operations: a little fuzzy physics?
We examine the behaviour of charged particles in homogeneous, constant and/or
oscillating magnetic fields in the non-relativistic approximation. A special
role of the geometric center of the particle trajectory is elucidated. In
quantum case it becomes a 'fuzzy point' with non-commuting coordinates, an
element of non-commutative geometry which enters into the traditional control
problems. We show that its application extends beyond the usually considered
time independent magnetic fields of the quantum Hall effect. Some simple cases
of magnetic control by oscillating fields lead to the stability maps differing
from the traditional Strutt diagram.Comment: 28 pages, 8 figure
Validation of Picture Free and Cued Selective Reminding Test for Illiteracy in Lima, Peru
Dementia in Latin America is a crucial public health problem. Identifying brief cognitive screening (BCS) tools for the primary care setting is crucial, particularly for illiterate individuals. We evaluated tool performance characteristics and validated the free and total recall sections of the Free and Cued Selective Reminding Test-Picture version (FCSRT-Picture) to discriminate between 63 patients with early Alzheimer?s disease dementia (ADD), 60 amnestic mild cognitive impairment (aMCI) and 64 cognitively healthy Peruvian individuals with illiteracy from an urban area. Clinical, functional, and cognitive assessments were performed. FCSRT-Picture performance was assessed using receiver operating characteristic curve analyses. The mean ± standard deviation scores were 7.7 ± 1.0 in ADD, 11.8 ± 1.6 in aMCI, and 29.5 ± 1.8 in controls. The FCSRT-Picture had better performance characteristics for distinguishing controls from aMCI compared with several other BCS tools, but similar characteristics between controls and early ADD. The FCSRT-Picture is a reliable BCS tool for illiteracy in Peru
Metagenome sequencing of the microbial community of a solar saltern crystallizer pond at cĂĄhuil lagoon, chile.
Cåhuil Lagoon in central Chile harbors distinct microbial communities in various solar salterns that are arranged as interconnected ponds with increasing salt concentrations. Here, we report the metagenome of the 3.0- to 0.2-”m fraction of the microbial community present in a crystallizer pond with 34% salinity
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