832 research outputs found
Why Don't Farmers Adopt Precision Farming Technologies in Cotton Production?
We used the 2009 Southern Cotton Precision Farming Survey data collected from farmers in twelve U.S. states (Alabama, Arkansas, Florida, Georgia, Louisiana, Missouri, Mississippi, North Carolina, South Carolina, Tennessee, Texas, and Virginia) to understand why farmers do not adopt seemingly profitable precision farming technology. Farmers provided cost, time constraint, satisfaction with the current practice and other as reasons for not adopting precision farming technology. Results from a multinomial logit regression model indicated that manure application on field, more formal education, larger farm size, participation in conservation easement or agricultural easement generally decreases the probability of nonadoption of precision agriculture in cotton production.precision agriculture, technology adoption, multinomial logit, Crop Production/Industries, Farm Management, Research and Development/Tech Change/Emerging Technologies, C25, Q16,
RecolorCloud: A Point Cloud Tool for Recoloring, Segmentation, and Conversion
Point clouds are a 3D space representation of an environment that was
recorded with a high precision laser scanner. These scanners can suffer from
environmental interference such as surface shading, texturing, and reflections.
Because of this, point clouds may be contaminated with fake or incorrect
colors. Current open source or proprietary tools offer limited or no access to
correcting these visual errors automatically.
RecolorCloud is a tool developed to resolve these color conflicts by
utilizing automated color recoloring. We offer the ability to deleting or
recoloring outlier points automatically with users only needing to specify
bounding box regions to effect colors. Results show a vast improvement of the
photo-realistic quality of large point clouds. Additionally, users can quickly
recolor a point cloud with set semantic segmentation colors.Comment: 6 Pages, 9 figures, 1 table, To be submitted to the ACM MMSys 2024
Conferenc
Latitudinal environmental niches and riverine barriers shaped the phylogeography of the central Chilean endemic Dioscorea humilis (Dioscoreaceae)
The effects of Pleistocene glaciations and geographical barriers on the phylogeographic patterns of lowland plant species in Mediterranean-climate areas of Central Chile are poorly understood. We used Dioscorea humilis (Dioscoreaceae), a dioecious geophyte extending 530 km from the Valparaíso to the Bío-Bío Regions, as a case study to disentangle the spatio-temporal evolution of populations in conjunction with latitudinal environmental changes since the Last Inter-Glacial (LIG) to the present. We used nuclear microsatellite loci, chloroplast (cpDNA) sequences and environmental niche modelling (ENM) to construct current and past scenarios from bioclimatic and geographical variables and to infer the evolutionary history of the taxa. We found strong genetic differentiation at nuclear microsatellite loci between the two subspecies of D. humilis, probably predating the LIG. Bayesian analyses of population structure revealed strong genetic differentiation of the widespread D. humilis subsp. humilis into northern and southern population groups, separated by the Maipo river. ENM revealed that the ecological niche differentiation of both groups have been maintained up to present times although their respective geographical distributions apparently fluctuated in concert with the climatic oscillations of the Last Glacial Maximum (LGM) and the Holocene. Genetic data revealed signatures of eastern and western postglacial expansion of the northern populations from the central Chilean depression, whereas the southern ones experienced a rapid southward expansion after the LGM. This study describes the complex evolutionary histories of lowland Mediterranean Chilean plants mediated by the summed effects of spatial isolation caused by riverine geographical barriers and the climatic changes of the Quaternary
Seed germination and seedling allogamy in Rosmarinus officinalis: the costs of inbreeding
1) Self-pollination by geitonogamy is likely in self-compatible plants that simultaneously expose large numbers of flowers to pollinators. However, the progeny of these plants is often highly allogamous. Although mechanisms to increase cross-pollination have been identified and studied, their relative importance has rarely been addressed simultaneously in plant populations.
(2) We used Rosmarinus officinalis to explore the factors that influence the probability of self-fertilization due to geitonogamy or that purge its consequences, focusing on their effect on seed germination and allogamy rate. For doing this, we experimentally tested the effects of geitonogamy on the proportion of filled seeds and how it influences germination rates. Then during two field seasons, we studied how life-history and flowering traits of individuals influence seed germination and allogamy rates of their progeny in wild populations at the extremes of the altitudinal range. The traits considered were plant size, population density, duration of the flowering season, number of open flowers, flowering synchrony among individuals within populations, and the proportion of male-sterile flowers.
(3) We found that most seeds obtained experimentally from self-pollinations were apparently healthy but in fact empty, and that the presence of filled seeds drove the differences in germination rates between self- and cross-pollination experiments. Plants from wild populations consistently showed low germination rates and high rates of allogamy as determined with microsatellites. Germination rates related positively to the length of the flowering season, flowering synchrony and the rate of male-sterile flowers whereas the rate of allogamous seedlings was positively related only to the rate of male-sterile flowers.
(4) Rosemary plants purge most of the inbreeding caused by its pollination system by aborting seeds. This study showed that the rates of seed germination and of the resulting allogamy are a function of a complex combination of factors that vary in space and time. Male sterility of flowers, length of the flowering season and flowering synchrony of individuals within populations all favor high rates of cross-pollination, therefore increasing germination and allogamy rates. These flowering traits appear to be highly plastic and respond to local and seasonal environmental conditions
In-depth study of Netflix’s original content of fictional series. Forms, styles and trends in the new streaming scene
This article presents an analysis of the original content of fictional series created by one of the leading companies in the streaming television market, Netflix. This work aims at offering an in-depth study of the original series of the company Netflix, which will allow to classify these contents according to their strategic nature and, secondly, to offer a formal taxonomic overview on them. In addition, their forms, formats, languages, genres and thematic descriptors are analysed in order to establish a taxonomy for the classification of Netflix’s original content. To this end, this article is based on a quantitative method with qualitative contributions, adopting a descriptive but also exploratory approach. Its sample is made up of 490 series available on the Spanish version of the platform from its beginning in 2013 to 2019. The results lead to find a commitment to the production of fictional series with a global nature, but also focused on the local through alliances and productive methods with local businesses. Furthermore, the importance of in-house production as a present and medium-term future strategy is highlighted, together with the commitment to the division of production languages, considering local languages as a resource for the acceptance of the products. As for the predominant formats, a new trend marks how new audiovisual products are created by focusing, among other things, on reducing the duration and longevity of the series broadcast by the company.El presente artículo analiza los contenidos originales de ficción seriada de una de las compañías líder en el mercado de la televisión in streaming como es Netflix. El objetivo general del trabajo es ofrecer una radiografía sobre las series originales de la compañía Netflix, que permita clasificar dichos contenidos según su naturaleza estratégica y, en segundo lugar, que ofrezca un panorama taxonómico formal sobre ellos. Además, se analizan las formas, formatos, idiomas, géneros y descriptores temáticos para establecer una taxonomía que permita clasificar dichos contenidos originales de Netflix. Para ello, el artículo se sustenta en un método cuantitativo con aportes cualitativos, basado en un enfoque descriptivo pero también exploratorio, y su muestra está formada por las 490 series emitidas en la versión española de la plataforma Netflix desde sus inicios en 2013 hasta 2019. Los resultados permiten detectar una apuesta por una producción de ficción seriada de corte global, pero con la mirada puesta en lo local, mediante las alianzas y fórmulas productivas con empresas locales. Además, se pone de manifiesto la importancia de la producción propia como estrategia presente y a medio plazo, unida a la apuesta por la bifurcación de los idiomas de producción, considerando los idiomas locales como recursos de aceptación de los productos emitidos. En cuanto a los formatos predominantes, se detecta una nueva tendencia que marca la forma de crear los nuevos productos audiovisuales, enfocándose, entre otros, en la reducción de la duración y la propia longevidad de las series emitidas por la compañía
Profiling embryonic stem cell differentiation by MALDI TOF mass spectrometry:development of a reproducible and robust sample preparation workflow
Signal Processing on Product Spaces
We establish a framework for signal processing on product spaces of
simplicial and cellular complexes. For simplicity, we focus on the product of
two complexes representing time and space, although our results generalize
naturally to products of simplicial complexes of arbitrary dimension. Our
framework leverages the structure of the eigenmodes of the Hodge Laplacian of
the product space to jointly filter along time and space. To this end, we
provide a decomposition theorem of the Hodge Laplacian of the product space,
which highlights how the product structure induces a decomposition of each
eigenmode into a spatial and temporal component. Finally, we apply our method
to real world data, specifically for interpolating trajectories of buoys in the
ocean from a limited set of observed trajectories
Past climate changes facilitated homoploid speciation in three mountain spiny fescues (Festuca, Poaceae)
Apart from the overwhelming cases of allopolyploidization, the impact of speciation through homoploid hybridization is becoming more relevant than previously thought. Much less is known, however, about the impact of climate changes as a driven factor of speciation. To investigate these issues, we selected Festuca picoeuropeana, an hypothetical natural hybrid between the diploid species F. eskia and F. gautieri that occurs in two different mountain ranges (Cantabrian Mountains and Pyrenees) separated by more than 400 km. To unravel the outcomes of this mode of speciation and the impact of climate during speciation we used a multidisciplinary approach combining genome size and chromosome counts, data from an extensive nuclear genotypic analysis, plastid sequences and ecological niche models (ENM). Our results show that the same homoploid hybrid was originated independently in the two mountain ranges, being currently isolated from both parents and producing viable seeds. Parental species had the opportunity to contact as early as 21000 years ago although niche divergence occurs nowadays as result of a climate-driven shift. A high degree of niche divergence was observed between the hybrid and its parents and no recent introgression or backcrossed hybrids were detected, supporting the current presence of reproductive isolation barriers between these species
Laser Calibration System for Time of Flight Scintillator Arrays
A laser calibration system was developed for monitoring and calibrating time
of flight (TOF) scintillating detector arrays. The system includes setups for
both small- and large-scale scintillator arrays. Following test-bench
characterization, the laser system was recently commissioned in experimental
Hall B at the Thomas Jefferson National Accelerator Facility for use on the new
Backward Angle Neutron Detector (BAND) scintillator array. The system
successfully provided time walk corrections, absolute time calibration, and TOF
drift correction for the scintillators in BAND. This showcases the general
applicability of the system for use on high-precision TOF detectors.Comment: 11 pages, 11 figure
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