194 research outputs found
Synopsis of Ipomoea L. and Merremia Dennst. ex Endl. (Convolvulaceae) in the North of Peru (Lambayeque and surrounding areas)
El objetivo principal de este trabajo es identificar y comentar los registros anteriores y nuevos de los géneros Ipomoea y Merremia en el departamento de Lambayeque (Perú) y zonas circundantes. Se describen 18 especies de Ipomoea
y 3 especies de Merremia: Ipomoea alba, I. asarifolia, I. hederifolia, I. indica, I. nil e
I. wrightii.
I. aristolochiifolia, I. batatas, I. cairica, I. carnea,I. incarnata, I. parasitica, I. piurensis,
I. purpurea, I. tiliacea,Merremia aegyptia, M. quinquefolia y M.umbellata son nuevos registros para la flora de Lambayeque. Incluso Ipomoea amnicola, I. dumetorum e I. quamoclit se reportan como nuevos registros en el departamento dyacente de Cajamarca. Se presentan claves para identificar las especies y los grupos intergenéricos. La distribución de cada especie es también presentada para mostrar su biogeografía
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
In search for the sources of plastic marine litter that contaminates the Easter Island Ecoregion
Subtropical gyres are the oceanic regions where plastic litter accumulates over long timescales, exposing surrounding oceanic islands to plastic contamination, with potentially severe consequences on marine life. Islands’ exposure to such contaminants, littered over long distances in marine or terrestrial habitats, is due to the ocean currents that can transport plastic over long ranges. Here, this issue is addressed for the Easter Island ecoregion (EIE). High-resolution ocean circulation models are used with a Lagrangian particle-tracking tool to identify the connectivity patterns of the EIE with industrial fishing areas and coastline regions of the Pacific basin. Connectivity patterns for “virtual” particles either floating (such as buoyant macroplastics) or neutrally-buoyant (smaller microplastics) are investigated. We find that the South American shoreline between 20°S and 40°S, and the fishing zone within international waters off Peru (20°S, 80°W) are associated with the highest probability for debris to reach the EIE, with transit times under 2 years. These regions coincide with the most-densely populated coastal region of Chile and the most-intensely fished region in the South Pacific. The findings offer potential for mitigating plastic contamination reaching the EIE through better upstream waste management. Results also highlight the need for international action plans on this important issue
Improvement of Aroma in Transgenic Potato As a Consequence of Impairing Tuber Browning
Sensory analysis studies are critical in the development of quality enhanced crops, and may be an important component in the public acceptance of genetically modified foods. It has recently been established that odor preferences are shared between humans and mice, suggesting that odor exploration behavior in mice may be used to predict the effect of odors in humans. We have previously found that mice fed diets supplemented with engineered nonbrowning potatoes (-PPO) consumed more potato than mice fed diets supplemented with wild-type potatoes (WT). This prompted us to explore a possible role of potato odor in mice preference for nonbrowning potatoes. Taking advantage of two well established neuroscience paradigms, the “open field test” and the “nose-poking preference test”, we performed experiments where mice exploration behavior was monitored in preference assays on the basis of olfaction alone. No obvious preference was observed towards -PPO or WT lines when fresh potato samples were tested. However, when oxidized samples were tested, mice consistently investigated -PPO potatoes more times and for longer periods than WT potatoes. Congruently, humans discriminated WT from -PPO samples with a considerably better performance when oxidized samples were tested than when fresh samples were tested in blind olfactory experiments. Notably, even though participants ranked all samples with an intermediate level of pleasantness, there was a general consensus that the -PPO samples had a more intense odor and also evoked the sense-impression of a familiar vegetable more often than the WT samples. Taken together, these findings suggest that our previous observations might be influenced, at least in part, by differential odors that are accentuated among the lines once oxidative deterioration takes place. Additionally, our results suggest that nonbrowning potatoes, in addition to their extended shelf life, maintain their odor quality for longer periods of time than WT potatoes. To our knowledge this is the first report on the use of an animal model applied to the sensory analysis of a transgenic crop
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Abundance determination of multiple star-forming regions in the HII galaxy SDSS J165712.75+321141.4
We analyze high signal-to-noise spectrophotometric observations acquired
simultaneously with TWIN, a double-arm spectrograph, from 3400 to 10400 \AA of
three star-forming regions in the HII galaxy SDSS J165712.75+321141.4. We have
measured four line temperatures: Te([OIII]), Te([SIII]), Te([OII]), and
Te([SII]), with high precision, rms errors of order 2%, 5%, 6% and 6%,
respectively, for the brightest region, and slightly worse for the other two.
The temperature measurements allowed the direct derivation of ionic abundances
of oxygen, sulphur, nitrogen, neon and argon.
We have computed CLOUDY tailor-made models which reproduce the O2+ measured
thermal and ionic structures within the errors in the three knots, with
deviations of only 0.1 dex in the case of O+ and S2+ ionic abundances. In the
case of the electron temperature and the ionic abundances of S+/H+, we find
major discrepancies which could be consequence of the presence of colder
diffuse gas. The star formation history derived using STARLIGHT shows a similar
age distribution of the ionizing population among the three star-forming
regions. This fact suggests a similar evolutionary history which is probably
related to a process of interaction with a companion galaxy that triggered the
star formation in the different regions almost at the same time. The hardness
of the radiation field mapped through the use of the softness parameter
is the same within the observational errors for all three regions, implying
that the equivalent effective temperature of the radiation fields are very
similar for all the studied regions of the galaxy, in spite of some small
differences in the ionization state of different elements.Comment: 18 pages, 10 figures, accepted by MNRA
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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