1,871 research outputs found
Production Management Model Based on Lean Manufacturing and Change Management Aimed at Reducing Order Fulfillment Times in Micro and Small Wooden Furniture Companies in Peru
This research study seeks to identify and prioritize the causes of order fulfillment delays in a small wooden furniture manufacturing company. The authors propose a 5-phase Lean Optimization model to address and reduce this problem. Post-implementation results yielded a 54.87% reduction in material search and transportation times, a 32.86% reduction in travel times between stations, and a 19.81% increase in line efficiency. In addition, order fulfillment percentages increased from 12.5% to 60%
Population fluctuation of Diaphorina citri Kuwayama (Hemiptera: Liviidae) and survey of some natural enemies in Ecuador
Diaphorina citri detected in Ecuador for the first time in 2013, is an insect pest of global relevance. It is the main vector of the phloem-limited bacterium Candidatus Liberibacter asiaticus, the causal agent of Huanglongbing (HLB), a devastating disease of citrus trees. During the period from April 2016 - July 2017, population fluctuation studies and a search for natural enemies of D. citri were conducted on young shoots of orange jessamine, Murraya paniculata, and Citrus spp. The natural enemies of D. citri were collected in the Provinces of Guayas and Santa Elena, Ecuador. A total of 1660 specimens of predators belonging to five species were collected, consisting of three coccinellids, Cheilomenes sexmaculata, the most abundant species (39.9%, P <0.05), followed by Cycloneda sanguinea (15.8%), and Paraneda pallidula guticollis (4.1%) (Coleoptera: Coccinellidae), an assassin bug, Zelus sp. (Hemiptera: Reduviidae) (17.8%), and the lacewing Ceraeochrysa sp. (Neuroptera: Chrysopidae) (22.4%). The parasitoid wasp Tamarixia radiata also was found, reaching a parasitization rate of 90% of the psyllid nymphs. This study represents the first report of P. pallidula guticollis feeding on D. citri. The diversity of natural enemies and the high level of parasitism detected suggest the importance of natural enemies as biological control agents of this important phytophagous insect pest. The natural control by these beneficial insects would make unnecessary the applications of chemical insecticides that are carried out in Ecuador for the control of this insect, especially at this moment when the HLB causing bacterium has not been reported in Ecuador.Diaphorina citri, especie detectada en Ecuador por primera vez en 2013, es una plaga de relevancia mundial debido a que es el principal vector de la bacteria Candidatus Liberibacter asiaticus, agente causal del Huanglongbing (HLB), una devastadora enfermedad de los cítricos. Durante el período abril 2016 – julio 2017, se realizaron estudios de fluctuación poblacional e inventario de enemigos naturales de D. citri en brotes jóvenes de azahar de la India, Murraya paniculata y citricos, Citrus spp. Los enemigos naturales fueron colectados en las provincias de Guayas y Santa Elena, Ecuador. Se colectaron un total de 1660 especímenes pertenecientes a cinco especies, entre estos, tres coccinélidos, Cheilomenes sexmaculata, la especie más abundante (39,9%, P<0,05), seguido por Cycloneda sanguinea (15,8%) y Paraneda pallidula guticollis 4,1% (Coleoptera: Coccinellidae), una chinche depredadora, Zelus sp. (Hemiptera: Reduviidae) (17,8%) y la crisopa Ceraeochrysa sp. (Neuroptera: Chrysopidae) (22,4%). La avispita parasítica Tamarixia radiata también fue encontrada,
alcanzando un porcentaje de parasitismo del 90% en las ninfas de psílido. Este estudio representa el primer reporte de P. pallidula guticollis alimentándose de D. citri. La diversidad de enemigos naturales y el alto nivel de parasitismo detectado sugieren la importancia de los enemigos naturales como agentes de control biológico de esta importante plaga. El control natural existente haría innecesarias las aplicaciones de insecticidas químicos que se llevan a cabo en el Ecuador para el control de este insecto, especialmente en este momento que el HLB no se ha encontrado en Ecuador.Gerencia de Comunicación Institucional, DG SICyP, INTAFil: Chavez, Y. Ministerio de Agricultura y Ganadería; EcuadorFil: Castro, C. Investigador independiente; EcuadorFil: González, Guillermo F. Investigador independiente; ChileFil: Castro, Jessenia. Universidad Técnica de Manabí. Facultad de Ingeniería Agronómica; EcuadorFil: Peñarrieta Bravo, Soraya. Universidad Técnica de Manabí. Facultad de Ingeniería Agronómica; EcuadorFil: Perez-Almeida, Iris. Universidad ECOTEC. Facultad de Ingenierías. Carrera de Ingeniería Agrónoma; EcuadorFil: Chirinos, Dorys Terezinha. Universidad Técnica de Manabí. Facultad de Ingeniería Agronómica; EcuadorFil: Kondo Rodríguez, Demian Takumasa. Corporación colombiana de investigación agropecuaria AGROSAVIA. Centro de Investigación Palmira; Colombi
Predicting cell types and genetic variations contributing to disease by combining GWAS and epigenetic data
Genome-wide association studies (GWASs) identify single nucleotide polymorphisms (SNPs) that are enriched in individuals suffering from a given disease. Most disease-associated SNPs fall into non-coding regions, so that it is not straightforward to infer phenotype or function; moreover, many SNPs are in tight genetic linkage, so that a SNP identified as associated with a particular disease may not itself be causal, but rather signify the presence of a linked SNP that is functionally relevant to disease pathogenesis. Here, we present an analysis method that takes advantage of the recent rapid accumulation of epigenomics data to address these problems for some SNPs. Using asthma as a prototypic example; we show that non-coding disease-associated SNPs are enriched in genomic regions that function as regulators of transcription, such as enhancers and promoters. Identifying enhancers based on the presence of the histone modification marks such as H3K4me1 in different cell types, we show that the location of enhancers is highly cell-type specific. We use these findings to predict which SNPs are likely to be directly contributing to disease based on their presence in regulatory regions, and in which cell types their effect is expected to be detectable. Moreover, we can also predict which cell types contribute to a disease based on overlap of the disease-associated SNPs with the locations of enhancers present in a given cell type. Finally, we suggest that it will be possible to re-analyze GWAS studies with much higher power by limiting the SNPs considered to those in coding or regulatory regions of cell types relevant to a given disease
Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter
An in-situ calibration of a logarithmic periodic dipole antenna with a
frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of
a radio station system used for detection of cosmic ray induced air showers at
the Engineering Radio Array of the Pierre Auger Observatory, the so-called
Auger Engineering Radio Array (AERA). The directional and frequency
characteristics of the broadband antenna are investigated using a remotely
piloted aircraft (RPA) carrying a small transmitting antenna. The antenna
sensitivity is described by the vector effective length relating the measured
voltage with the electric-field components perpendicular to the incoming signal
direction. The horizontal and meridional components are determined with an
overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} %
respectively. The measurement is used to correct a simulated response of the
frequency and directional response of the antenna. In addition, the influence
of the ground conductivity and permittivity on the antenna response is
simulated. Both have a negligible influence given the ground conditions
measured at the detector site. The overall uncertainties of the vector
effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in
the square root of the energy fluence for incoming signal directions with
zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is
unchanged with respect to v2. 39 pages, 15 figures, 2 table
Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory
We report a multi-resolution search for anisotropies in the arrival
directions of cosmic rays detected at the Pierre Auger Observatory with local
zenith angles up to and energies in excess of 4 EeV ( eV). This search is conducted by measuring the angular power spectrum
and performing a needlet wavelet analysis in two independent energy ranges.
Both analyses are complementary since the angular power spectrum achieves a
better performance in identifying large-scale patterns while the needlet
wavelet analysis, considering the parameters used in this work, presents a
higher efficiency in detecting smaller-scale anisotropies, potentially
providing directional information on any observed anisotropies. No deviation
from isotropy is observed on any angular scale in the energy range between 4
and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no
other deviation from isotropy is observed for moments beyond the dipole one.
The corresponding -values obtained after accounting for searches blindly
performed at several angular scales, are in the case of
the angular power spectrum, and in the case of the needlet
analysis. While these results are consistent with previous reports making use
of the same data set, they provide extensions of the previous works through the
thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory
On September 14, 2015 the Advanced LIGO detectors observed their first
gravitational-wave (GW) transient GW150914. This was followed by a second GW
event observed on December 26, 2015. Both events were inferred to have arisen
from the merger of black holes in binary systems. Such a system may emit
neutrinos if there are magnetic fields and disk debris remaining from the
formation of the two black holes. With the surface detector array of the Pierre
Auger Observatory we can search for neutrinos with energy above 100 PeV from
point-like sources across the sky with equatorial declination from about -65
deg. to +60 deg., and in particular from a fraction of the 90% confidence-level
(CL) inferred positions in the sky of GW150914 and GW151226. A targeted search
for highly-inclined extensive air showers, produced either by interactions of
downward-going neutrinos of all flavors in the atmosphere or by the decays of
tau leptons originating from tau-neutrino interactions in the Earth's crust
(Earth-skimming neutrinos), yielded no candidates in the Auger data collected
within s around or 1 day after the coordinated universal time (UTC)
of GW150914 and GW151226, as well as in the same search periods relative to the
UTC time of the GW candidate event LVT151012. From the non-observation we
constrain the amount of energy radiated in ultrahigh-energy neutrinos from such
remarkable events.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
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