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1.
Plant Cell Environ ; 47(2): 664-681, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37927215

RESUMEN

Despite decades of research resulting in a comprehensive understanding of epicuticular wax metabolism, the function of these almost ubiquitous metabolites in plant-herbivore interactions remains unresolved. In this study, we examined the effects of CRISPR-induced knockout mutations in four Nicotiana glauca (tree tobacco) wax metabolism genes. These mutations cause a wide range of changes in epicuticular wax composition, leading to altered interactions with insects and snails. Three interaction classes were examined: chewing herbivory by seven caterpillars and one snail species, phloem feeding by Myzus persicae (green peach aphid) and oviposition by Bemisia tabaci (whitefly). Although total wax load and alkane abundance did not affect caterpillar growth, a correlation across species, showed that fatty alcohols, a minor component of N. glauca surface waxes, negatively affected the growth of both a generalist caterpillar (Spodoptera littoralis) and a tobacco-feeding specialist (Manduca sexta). This negative correlation was overshadowed by the stronger effect of anabasine, a nicotine isomer, and was apparent when fatty alcohols were added to an artificial lepidopteran diet. By contrast, snails fed more on waxy leaves. Aphid reproduction and feeding activity were unaffected by wax composition but were potentially affected by altered cutin composition. Wax crystal morphology could explain the preference of B. tabaci to lay eggs on waxy wild-type plants relative to both alkane and fatty alcohol-deficient mutants. Together, our results suggest that the varied responses among herbivore classes and species are likely to be a consequence of the co-evolution that shaped the specific effects of different surface wax components in plant-herbivore interactions.


Asunto(s)
Alcoholes Grasos , Herbivoria , Animales , Femenino , Herbivoria/fisiología , Ceras , Alcanos , Productos de Tabaco
2.
J Exp Bot ; 74(6): 1745-1750, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36651787

RESUMEN

Aphids are important herbivorous insects that can cause significant crop damage, leading to yield reduction and economic loss. One avenue being explored to reduce aphid impacts is the development of aphid-resistant plants. Under projected climate scenarios, it is expected that plants will be exposed to greater biotic and abiotic stress, including increased herbivorous insect infestation and exposure to prolonged periods of environmental stress, particularly drought. In response to these projections, plant-aphid interactions under drought conditions have been a subject of growing interest; however, few studies have looked at the impact of drought stress on plant resistance to aphids despite the potential importance for plant breeding. Here, we examine the latest scientific advances regarding variation in plant resistance to aphids under drought, emphasizing underlying mechanisms and functional trade-offs and propose a conceptual model relating plant tolerance to drought with plant resistance to aphids.


Asunto(s)
Áfidos , Animales , Áfidos/fisiología , Sequías , Fitomejoramiento , Estrés Fisiológico , Herbivoria , Plantas
3.
Rev Panam Salud Publica ; 47: e11, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36909803

RESUMEN

Antineoplastic drugs (ANDs) used for chemotherapy can cause secondary cancers in treated patients and can pose carcinogenic risks to health-sector workers anywhere along these drugs' life cycle in a facility, from production to patient administration. Several PAHO/WHO Collaborating Centers (CCs) have experience addressing these hazards in the health sector. The objectives of this report are four-fold: 1) Provide an overview of longstanding research and prevention efforts, led by PAHO/WHO and its Occupational Health CCs, aimed at reducing the burden of occupational cancer in the Americas; 2) Discuss how robust AND exposure assessment and educational/outreach work by PAHO CCs can form the basis of exposure mitigation efforts among health-sector workers; 3) Through the presentation of original AND exposure assessment data from a pharmaceutical compounding facility in Chile, highlight relatively inexpensive methods by which such data can be generated; and 4) Discuss how effective, periodic environmental surveillance in healthcare facilities results in the identification of AND contamination in the work environment and enables the implementation of low-cost, high-impact interventions to reduce the risk of occupational cancer in health-sector workers, including in limited-resource settings. The risk of health-sector worker exposure to ANDs and other hazardous drugs is an important issue for inclusion within PAHO/WHO's broader efforts at reducing the impact of occupational cancer in the Americas. This report demonstrates that a wide range of accessible AND-exposure mitigation strategies are feasible at both a facility and a national policy level across the hemisphere.


Los medicamentos antineoplásicos empleados en quimioterapia pueden causar distintos tipos de tumores secundarios en pacientes tratados y presentar riesgos cancerígenos para los trabajadores del sector de la salud en cualquier momento del ciclo de vida de estos medicamentos en las instalaciones, desde su producción hasta su administración al paciente. Varios centros colaboradores de la OPS/OMS tienen experiencia en cuanto a cómo abordar estos peligros en el sector de la salud. Este informe persigue cuatro objetivos: 1) ofrecer una visión general de la labor de investigación y prevención de larga data, liderada por la OPS/OMS y sus centros colaboradores de salud ocupacional, encaminada a reducir la carga del cáncer ocupacional en la Región de las Américas; 2) abordar cómo una evaluación sólida de la exposición a los medicamentos antineoplásicos y la labor educativa y divulgativa de los centros colaboradores de la OPS pueden sentar las bases de los esfuerzos de mitigación de la exposición en los trabajadores del sector de la salud; 3) mediante la presentación de datos originales sobre la evaluación de la exposición a los medicamentos antineoplásicos en una instalación de compuestos farmacéuticos en Chile, destacar métodos relativamente asequibles gracias a los cuales se pueden recopilar dichos datos; y 4) examinar cómo la vigilancia ambiental efectiva y periódica en los centros de salud permite detectar casos de contaminación de medicamentos antineoplásicos en el entorno de trabajo y facilita la ejecución de intervenciones de bajo costo y alto impacto para reducir el riesgo de cáncer ocupacional en los trabajadores del sector de la salud, incluso en entornos de recursos limitados.El riesgo de exposición de los trabajadores del sector de la salud a los medicamentos antineoplásicos y otros medicamentos peligrosos es una cuestión importante para su inclusión en los esfuerzos más amplios de la OPS/OMS para reducir los efectos del cáncer ocupacional en la Región de las Américas. En este informe se demuestra que una amplia gama de estrategias accesibles de mitigación de la exposición a los medicamentos antineoplásicos es factible tanto a nivel de las instalaciones como de las políticas nacionales en toda la Región.


Os medicamentos antineoplásicos usados para quimioterapia podem causar cânceres secundários em pacientes tratados e apresentar riscos carcinogênicos aos profissionais de saúde em qualquer momento do ciclo de vida desses fármacos dentro de um estabelecimento, desde sua produção até a administração ao paciente. Vários centros colaboradores da OPAS/OMS têm experiência em lidar com esses riscos no setor de saúde. Este relatório tem quatro objetivos: 1) fornecer uma visão geral dos esforços de longa data em pesquisa e prevenção liderados pela OPAS/OMS e por seus centros colaboradores de saúde ocupacional, cuja meta é reduzir a carga do câncer ocupacional nas Américas; 2) discutir como uma avaliação robusta da exposição aos antineoplásicos e o trabalho de extensão/educacional dos centros colaboradores da OPAS/OMS podem embasar os esforços de mitigação da exposição entre os profissionais de saúde; 3) por meio da apresentação de dados originais de avaliação da exposição a antineoplásicos obtidos de uma central de manipulação de medicamentos no Chile, destacar métodos relativamente econômicos para gerar esse tipo de dados; e 4) discutir como a vigilância ambiental eficaz e periódica em estabelecimentos de saúde resulta na identificação de contaminação por antineoplásicos no ambiente de trabalho e permite a implementação de intervenções de baixo custo e alto impacto para reduzir o risco de câncer ocupacional em profissionais de saúde, inclusive em contextos de recursos limitados.O risco de exposição dos profissionais de saúde aos medicamentos antineoplásicos e outros fármacos perigosos é uma questão importante a ser incluída nos esforços mais amplos da OPAS/OMS de reduzir o impacto do câncer ocupacional nas Américas. Este relatório demonstra a viabilidade de uma ampla gama de estratégias acessíveis de mitigação da exposição aos antineoplásicos, tanto no nível das instituições quanto no âmbito de políticas nacionais em todo o hemisfério.

4.
Rev Med Chil ; 151(4): 453-460, 2023 Apr.
Artículo en Español | MEDLINE | ID: mdl-38687520

RESUMEN

INTRODUCTION: Poisonings are a worldwide preventable public health problem that affects the general population. OBJECTIVE: To epidemiologically characterize BZ and AD poisonings registered in Chile between 2002 and 2019. METHODS: An observational retrospective study of poisonings registered in the medical outcome report system of the Chilean Ministry of Health was conducted. The World Health Organization International Classification of Disease codes T42.2, T43.0 and T43.2 were included. RESULTS: 22,807 poisonings associated with BZ or AD were identified, representing 0.08% of all hospitalizations. Poisoning rates distribution were established at regional and national level. There were 9.8% of accidental events, 63.7% of intentional events, and 26.5% of undetermined cases. The highest accidental and intentional poisoning rates were estimated at the ages of 0 to 4 and 15 to 19 years old respectively. Poisoned patients remained hospitalized on average for 3.4 days. 0.3% of cases were related to death of patients. CONCLUSIONS: Poisoning events were characterized according to the studied variables. National poisoning rates decreased over the years with prevalence of those intentional events linked to women. Efforts should be made in creating poisoning prevention campaigns focused on age-based groups in the general population.


Asunto(s)
Antidepresivos , Benzodiazepinas , Humanos , Chile/epidemiología , Femenino , Adolescente , Masculino , Estudios Retrospectivos , Benzodiazepinas/envenenamiento , Adulto , Adulto Joven , Niño , Lactante , Preescolar , Persona de Mediana Edad , Antidepresivos/envenenamiento , Anciano , Distribución por Edad , Distribución por Sexo , Hospitalización/estadística & datos numéricos , Prevalencia , Intoxicación/epidemiología , Recién Nacido
5.
Clin Infect Dis ; 74(2): 343-346, 2022 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-33881476

RESUMEN

We report severe acute respiratory syndrome coronavirus 2 antibody positivity among market and city bus depot workers in Lima, Peru. Among 1285 vendors from 8 markets, prevalence ranged from 27% to 73%. Among 488 workers from 3 city bus depots, prevalence ranged from 11% to 47%. Self-reported symptoms were infrequent.


Asunto(s)
COVID-19 , SARS-CoV-2 , Personal de Salud , Humanos , Perú/epidemiología , Prevalencia
6.
Appl Opt ; 60(5): 1182-1190, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33690548

RESUMEN

We present a comparison of the first numerical and experimental results for the scattering of light from rough surfaces using a recently developed variable coherence polarimetry source that permits obtaining information on the object without having to scan over incidence or scatter angle. We present, for the first time, we believe, the application of this source to a 1D rough surface and show how to analyze the scattered field to retrieve useful information about the surface. This source uses a liquid-crystal phase modulator to control the polarization as well as the coherence of the beam illuminating the rough surface. Changing the polarization state distribution at the source plane, by controlling the phase distribution on a spatial light modulator, gives a scan of two source spots over the rough surface. The scattered beam is analyzed with a Stokes polarimeter. The Kirchhoff approximation is used to calculate the scattered Stokes vector using the experimental incident Stokes vector and intensity distribution as a source. Good agreement is obtained between the numerical and experimental results, for a simple calculation of the number of intensity maxima obtained as the two first-order source spots are scanned across the sample.

7.
Appl Opt ; 60(11): 2998-3005, 2021 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-33983193

RESUMEN

We present a comparison of two experimental methods to measure retardance as a function of applied voltage and as a function of position over the aperture of liquid-crystal variable retarders. These measurements are required for many applications, particularly in polarimetry. One method involves the scan of an unexpanded laser beam over the aperture, and the other uses an expanded beam from a LED and a CCD camera to measure the full aperture with a single measurement. The first method is time consuming, is limited in the measured spatial resolution, and requires more expensive equipment to perform the scan, whereas the second method is low cost, with the spatial resolution of the CCD, and fast, but in principle has variations of the incident beam over the aperture that affect the measured retardance values. The results obtained show good agreement for the average values of retardance for the two methods, but the expanded-beam method shows more noise, particularly close to the voltage values at which the variable-retarder retardance versus voltage curves are unwrapped. These retardance variations can be reduced by smoothing the retardance image, which makes the expanded-beam method an attractive method for polarimetry applications since it gives the complete information in the full aperture of the device with the additional advantages of low cost, simplicity, and being less time consuming.

8.
Plant Dis ; 102(11): 2201-2204, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30216126

RESUMEN

Melampsora larici-populina Kleb. is a Eurasian species that causes leaf rust of many species of Populus from sections Tacamahaca and Aigeiros. This rust has been inadvertently introduced to many parts around the world affecting poplar species that grow naturally, which may be susceptible to this fungus. In Chile, early European settlers introduced poplars; rust, attributed to M. larici-populina, has been reported in these trees since 1918. However, a modern confirmation has been lacking, and pathogenic variation of the Chilean population of M. larici-populina has not been investigated. Using a morphological analysis of urediniospores and sequencing of internal transcribed spacer (ITS) regions, we confirmed the presence of M. larici-populina in Chile. ITS regions exhibited 100% homology with M. larici-populina. Scanning electron microscopy showed that spores were 26 to 47 µm in length, 13 to 16 µm in width, and echinulate except for apices, which are smooth, characteristics described for this species of rust. The variability of M. larici-populina is characterized by the presence of pathotypes, which allows the fungus to infect despite the resistance of certain poplar hybrids. We concluded that the identified spores belong to M. larici-populina, with virulences 1, 2, 3, 4, 5, and 6. These results describe variation in virulence of M. larici-populina, which suggests the presence of a sexual stage in Chile.


Asunto(s)
Basidiomycota/patogenicidad , Enfermedades de las Plantas/microbiología , Populus/microbiología , Basidiomycota/genética , Basidiomycota/aislamiento & purificación , Basidiomycota/ultraestructura , Chile , Virulencia
9.
Hum Mol Genet ; 23(13): 3537-51, 2014 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-24584571

RESUMEN

Age-related macular degeneration (AMD) is the leading cause of vision loss in developed countries. While linked to genetic polymorphisms in the complement pathway, there are many individuals with high risk alleles that do not develop AMD, suggesting that other 'modifiers' may be involved. Mitochondrial (mt) haplogroups, defined by accumulations of specific mtDNA single nucleotide polymorphisms (SNPs) which represent population origins, may be one such modifier. J haplogroup has been associated with high risk for AMD while the H haplogroup is protective. It has been difficult to assign biological consequences for haplogroups so we created human ARPE-19 cybrids (cytoplasmic hybrids), which have identical nuclei but mitochondria of either J or H haplogroups, to investigate their effects upon bioenergetics and molecular pathways. J cybrids have altered bioenergetic profiles compared with H cybrids. Q-PCR analyses show significantly lower expression levels for seven respiratory complex genes encoded by mtDNA. J and H cybrids have significantly altered expression of eight nuclear genes of the alternative complement, inflammation and apoptosis pathways. Sequencing of the entire mtDNA was carried out for all the cybrids to identify haplogroup and non-haplogroup defining SNPs. mtDNA can mediate cellular bioenergetics and expression levels of nuclear genes related to complement, inflammation and apoptosis. Sequencing data suggest that observed effects are not due to rare mtDNA variants but rather the combination of SNPs representing the J versus H haplogroups. These findings represent a paradigm shift in our concepts of mt-nuclear interactions.


Asunto(s)
Apoptosis/fisiología , Núcleo Celular/metabolismo , ADN Mitocondrial/genética , Mitocondrias/metabolismo , Apoptosis/genética , Humanos , Polimorfismo de Nucleótido Simple/genética
10.
J Insect Sci ; 162016.
Artículo en Inglés | MEDLINE | ID: mdl-27012867

RESUMEN

Hylamorpha elegans(Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs inH. elegans as well as six new volatiles released by its native host Nothofagus obliqua(Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. oblique revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies.


Asunto(s)
Escarabajos/metabolismo , Fagaceae/química , Receptores Odorantes/metabolismo , Sesquiterpenos/metabolismo , Compuestos Orgánicos Volátiles/aislamiento & purificación , Animales , Secuencia de Bases , Escarabajos/genética , Femenino , Ligandos , Masculino , Simulación del Acoplamiento Molecular/métodos , Datos de Secuencia Molecular , Control Biológico de Vectores , Reacción en Cadena de la Polimerasa , Receptores Odorantes/genética
12.
Biochim Biophys Acta ; 1842(2): 208-19, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24200652

RESUMEN

The geographic origins of populations can be identified by their maternally inherited mitochondrial DNA (mtDNA) haplogroups. This study compared human cybrids (cytoplasmic hybrids), which are cell lines with identical nuclei but mitochondria from different individuals with mtDNA from either the H haplogroup or L haplogroup backgrounds. The most common European haplogroup is H while individuals of maternal African origin are of the L haplogroup. Despite lower mtDNA copy numbers, L cybrids had higher expression levels for nine mtDNA-encoded respiratory complex genes, decreased ATP (adenosine triphosphate) turnover rates and lower levels of reactive oxygen species production, parameters which are consistent with more efficient oxidative phosphorylation. Surprisingly, GeneChip arrays showed that the L and H cybrids had major differences in expression of genes of the canonical complement system (5 genes), dermatan/chondroitin sulfate biosynthesis (5 genes) and CCR3 (chemokine, CC motif, receptor 3) signaling (9 genes). Quantitative nuclear gene expression studies confirmed that L cybrids had (a) lower expression levels of complement pathway and innate immunity genes and (b) increased levels of inflammation-related signaling genes, which are critical in human diseases. Our data support the hypothesis that mtDNA haplogroups representing populations from different geographic origins may play a role in differential susceptibilities to diseases.


Asunto(s)
Población Negra/genética , ADN Mitocondrial/genética , Metabolismo Energético/genética , Haplotipos/genética , Población Blanca/genética , Adenosina Trifosfato/metabolismo , Adulto , Línea Celular , Proliferación Celular , Dosificación de Gen , Perfilación de la Expresión Génica , Genes Mitocondriales/genética , Predisposición Genética a la Enfermedad/etnología , Predisposición Genética a la Enfermedad/genética , Humanos , Células Híbridas/citología , Células Híbridas/metabolismo , Lactatos/metabolismo , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido Simple , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
13.
Opt Lett ; 40(17): 4142-5, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26368732

RESUMEN

This Letter proposes a new optical architecture based on a double-sideband filter, simultaneously applied at the Fourier plane, for inline digital holography. The proposed architecture not only allows removal of the conjugate images in the reconstruction process but also reduces the distortions that usually appear when using a single-sideband filter. We first introduce the mathematical model that explains the method and then describe the optical setup used for the implementation. The optical system includes a parallel aligned liquid crystal display placed at the Fourier plane that simultaneously filters positive and negative frequencies, when properly combined with linear polarizers. This feature makes the device useful to register dynamic processes. Finally, we tested the setup by registering a holographic movie of microscopic moving objects placed at different planes.

14.
Opt Lett ; 40(16): 3790-3, 2015 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-26274661

RESUMEN

An optical setup able to generate arbitrary states of polarization (SOPs) with customized degree of polarization is presented in this Letter. Compared with the few alternatives existing in literature, it presents an easy-to-build optical setup and leads to a superior performance. In fact, experimental results are presented, providing an accurate control for the generation of SOPs (maximum error of 1.7% and 3.3% for ellipticity and azimuth, respectively) as well as for the associated degree of polarization (full experimental variation from 1 up to 0.003, with a 1.7% maximum error). The system proposed may be useful for different applications, for example, for polarimeters testing, speckle metrology, and biological applications.

15.
J Econ Entomol ; 108(1): 277-85, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26470131

RESUMEN

The codling moth, Cydia pomonella (L.), is the key pest of apple production worldwide. Insecticide resistance has been reported in all producing countries, based on five different mechanisms. Codling moth in Chile has resistance to azinphos-methyl and tebufenozide in post-diapausing larvae. However, there are no studies about the susceptibility of these populations to insecticides from other chemical groups. Therefore, the efficacy of azinphos-methyl, chlorpyrifos-ethyl, esfenvalerate, methoxyfenozide, tebufenozide, and thiacloprid on neonate and post-diapausing larvae from six field populations was investigated, and identified resistance mechanisms in this species were evaluated. Neonate larvae were susceptible to all insecticides studied, but post-diapausing larvae from four populations were resistant to chlorpyrifos, one of them was also resistant to azinphos-methyl, and another one was resistant to tebufenozide. The acetylcholinesterase insensitivity mutation was not detected, and the sodium channel knockdown resistance mutation was present in a low frequency in one population. Detoxifying enzymatic activity of glutathione S-transferases, esterases, and cytochrome P-450 monooxygenases in adults differed among populations, but chlorpyrifos resistance was associated only with a decreased esterase activity as shown by a significant negative correlation between chlorpyrifos mortality and esterase activity.


Asunto(s)
Resistencia a los Insecticidas/fisiología , Mariposas Nocturnas/enzimología , Animales , Femenino , Masculino , Mariposas Nocturnas/genética , Organofosfatos
16.
J Econ Entomol ; 107(1): 268-76, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24665710

RESUMEN

Poplars are frequently attacked by aphids. The differential susceptibility of poplar hybrids to the aphid Chaitophorus leucomelas Koch (Sternorrhyncha: Aphididae) has been described, but the mechanism underlying this pattern is unknown. This work tested the hypothesis that poplar resistance to this aphid is associated with the presence of volatiles and secondary plant compounds that affect host selection and feeding behavior. This hypothesis was tested by studying the host choice and feeding behavior of C. leucomelas on two poplar hybrids with contrasting susceptibilities to this aphid ([Populus trichocarpa Torrey & Gray x Populus deltoides Bartram ex Marshall] x P. deltoides [TD x D], and [P. trichocarpa x Populus maximowiczii Henry] x [P. trichocarpa x P. maximowiczii] [TM x TM]). The results showed that C. leucomelas rejected leaves of the TM x TM hybrid and did not prefer odors from either hybrid. Electronic monitoring of the probing behavior of C. leucomelas suggested the involvement of antifeedant factors in the TM x TM hybrid. In addition, the chemical characterization of volatiles, epicuticular waxes, and internal phenols of leaves from both poplar hybrids revealed that TM x TM had a higher abundance of monoterpenes, sesquiterpenes, n-alkanes, and phenols. These results are discussed in terms of their contribution to poplar breeding programs aimed at enhancing insect resistance.


Asunto(s)
Áfidos , Preferencias Alimentarias , Herbivoria , Populus/química , Compuestos Orgánicos Volátiles/química , Animales , Cromatografía de Gases y Espectrometría de Masas , Olfatometría , Fenoles/química , Hojas de la Planta/química , Ceras/química
17.
Pest Manag Sci ; 80(4): 1949-1956, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38088471

RESUMEN

BACKGROUND: Facultative bacterial endosymbionts have the potential to influence the interactions between aphids, their natural enemies, and host plants. Among the facultative symbionts found in populations of the grain aphid Sitobion avenae in central Chile, the bacterium Regiella insecticola is the most prevalent. In this study, we aimed to investigate whether infected and cured aphid lineages exhibit differential responses to wheat cultivars containing varying levels of the benzoxazinoid DIMBOA (2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one), which is a xenobiotic compound produced by plants. Specifically, we examined the reproductive performance responses of the most frequently encountered genotypes of Sitobion avenae when reared on wheat seedlings expressing low, medium, and high concentrations of DIMBOA. RESULTS: Our findings reveal that the intrinsic rate of population increase (rm ) in cured lineages of Sitobion avenae genotypes exhibits a biphasic pattern, characterized by the lowest rm and an extended time to first reproduction on wheat seedlings with medium levels of DIMBOA. In contrast, the aphid genotypes harbouring Regiella insecticola display idiosyncratic responses, with the two most prevalent genotypes demonstrating improved performance on seedlings featuring an intermediate content of DIMBOA compared to their cured counterparts. CONCLUSION: This study represents the first investigation into the mediating impact of facultative endosymbionts on aphid performance in plants exhibiting varying DIMBOA contents. These findings present exciting prospects for identifying novel targets for aphid control by manipulating the presence of aphid symbionts. © 2023 Society of Chemical Industry.


Asunto(s)
Áfidos , Benzoxazinas , Animales , Áfidos/fisiología , Triticum , Reproducción , Enterobacteriaceae/genética , Bacterias
18.
Opt Express ; 21(7): 8116-25, 2013 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-23571901

RESUMEN

In this work a novel point diffraction interferometer based on a variable liquid crystal wave plate (LCWP) has been implemented. The LCWP consists of a 3x3 cm(2) monopixel cell with parallel alignment. The monopixel cell was manufactured such that the electrode covers the entire surface except in a centered circular area of 50 µm of diameter. This circle acts as a point perturbation which diffracts the incident wave front giving rise to a spherical reference wave. By applying a voltage to the LCWP we can change the phase of the wave front that passes through the monopixel, except at the center. Phase shifting techniques are used in order to calculate the amplitude and phase distribution of the object wave front. The system allows a digital hologram to be obtained, and by using the Fresnel diffraction integral it is possible to digitally reconstruct the different planes that constitute the three dimensional object.


Asunto(s)
Interferometría/instrumentación , Cristales Líquidos/química , Cristales Líquidos/efectos de la radiación , Refractometría/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Campos Electromagnéticos , Diseño de Equipo , Análisis de Falla de Equipo
19.
Ann Vasc Surg ; 27(7): 954-8, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23993111

RESUMEN

BACKGROUND: The aim of this study was to document the long-term results of open surgical treatment of aneurysms of the digestive arteries. METHODS: Between January 2000 and March 2010, 60 patients were operated on for 78 aneurysms of the digestive arteries at our institution. The mean age of patients was 61 years (31-84 years). The average lesion diameter was 33 mm (range 10-90 mm). Topographic distribution involved the coeliac trunk in 23 cases (30%), hepatic artery in 20 (26%), splenic artery in 19 (24%), superior mesenteric artery in 11 (14%), gastroduodenal artery in 3 (4%), and pancreaticoduodenal arteries in 2 (3%). Twenty patients (33%) were symptomatic, 1 of whom presented with aneurysmal rupture (1.7%). Follow-up was prospective and an actuarial analysis was carried out. Only 3 patients (5%) were lost to follow-up. RESULTS: Hospital mortality was 1.7% (upper gastrointestinal bleeding from gastric metastases of a kidney cancer). Postoperative complications were mainly respiratory (18%), digestive (18%), and renal (13%). Five reintervention procedures (8%) were necessary: 2 for colonic ischemia; 1 for intestinal bleeding; 1 for secondary graft infection due to peritonitis; and 1 for drainage of an acute pancreatitis. The average follow-up was 42 months (range 1-120 months). The actuarial survival rates were 98% at 1 month and 1 year, and 97% at 5 and 10 years, respectively. One late death occurred at 22 months (bronchopulmonary cancer). Three late reinterventions were carried out: 2 re-establishments of digestive continuity and 1 embolization for a recurrent aneurysm 7 years after the initial operation. The primary patency rate of the revascularizations was 98% at 1 month and 1 year, and 95% at 5 and 10 years. The rates of indemnity of restenosis or thrombosis were 98% at 1 month and 1 year, and 95% and 93% to 5 and 10 years, respectively. The rates of freedom of reintervention on bypasses were 98% at 1 month and 1 and 5 years, and 97% at 10 years. CONCLUSION: Open surgical treatment of aneurysms of the digestive arteries offers excellent long-term results in terms of patency. It is with these late results that endovascular techniques will have to be compared to define the best therapeutic strategy.


Asunto(s)
Aneurisma/cirugía , Sistema Digestivo/irrigación sanguínea , Procedimientos Quirúrgicos Vasculares , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma/diagnóstico , Aneurisma/mortalidad , Aneurisma/fisiopatología , Aneurisma Roto/cirugía , Arteria Celíaca/cirugía , Femenino , Arteria Hepática/cirugía , Humanos , Estimación de Kaplan-Meier , Masculino , Arteria Mesentérica Superior/cirugía , Persona de Mediana Edad , Complicaciones Posoperatorias/cirugía , Recurrencia , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Arteria Esplénica/cirugía , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Grado de Desobstrucción Vascular , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/mortalidad
20.
J Econ Entomol ; 116(5): 1662-1670, 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37441732

RESUMEN

Leucoptera sinuella (Reutti) (Lepidoptera: Lyonetiidae) is a leaf miner specialist on Salicaceae recently introduced to Chile and Argentina, where it is causing economic damage to poplar plantations. We report a field survey in a poplar nursery naturally infested showing that regardless of the poplar hybrid taxon, high variability in resistance was observed among clones within families for oviposition and leaf-mining damage. A group of susceptible and resistant hybrid poplar clones was then selected for a laboratory evaluation of oviposition (antixenosis) and leaf-mining damage (antibiosis) on potted, rooted shoot cuttings. The concentration of condensed tannins (CTs) and salicinoid phenolic glucosides (SPGs) of the leaves of the selected clones from the laboratory study was also measured. Total oviposited eggs were positively correlated with leaf area, with the lowest oviposition on TMxT 11372 clone. The lowest percentage of mined leaf area was obtained for clones TMxT 11372, TMxT 11463, and TDxD 17574, but surprisingly no correlation between the percentage of mined leaf area and concentration of CTs and SPGs was found. Resistant poplar hybrids of our study could be suitable for breeding programs aimed for L. sinuella integrated pest management.

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