1,629 research outputs found
A fluorometric method for determining chlorophylls a, b, and c
A method for the determination of chlorophylls a, b, and c by fluorometric techniques is presented. The effects of accessory carotenoids and chlorophyll derivatives on the accuracy of this method are analyzed…
Concentration and state of cerium in coastal waters
The cerium contents of several coastal water samples were found to be 0.1 to 0.6 µg/l. These are in contrast to the cerium concentrations of 0.004 and 0.014 µg/l observed in samples taken near Bermuda…
Comparison and evaluation of currently employed modifications of the Winkler method for determining dissolved oxygen in seawater; A NASCO report
This report discusses the basic chemistry of the Winkler procedure as well as various results obtained from fi eld and laborator y studies and experiments designed to determine the accuracy or precision of measuring the concentration of dissolved oxygen in seawater with currently used modifications of the Winkler method...
IV. Fossil Fishes From The Miocene Ellensburg Formation, South Central Washington
The Ellensburg Formation was named for sediments deposited in the Kittitas Valley along the Yakima River near Ellensburg, Washington (Russell, 1893, 1900). Similar beds are present to the south along the leeward front of the emerging central Cascade Mountains; including the Nile, Selah, Yakima, and Toppenish basins. Further south along the Columbia River, portions of the Dalles Group, Rhododendron Formation, and Sandy River Mudstone are likely temporal equivalents; the latter two of which are found on the windward side of the uplifting Cascade Range (Farooqui, et al., 1981; Evarts et al., 2009).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146545/1/MP 204vol4.pdfDescription of MP 204vol4.pdf : Main Articl
Field host range of Apanteles opuntiarum (Hymenoptera: Braconidae) in Argentina, a potential biocontrol agent of Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America
Field exploration in Argentina for cactophagous lepidopteran hosts parasitized by the recently described braconid parasitoid Apanteles opuntiarum Martínez & Berta (Hymenoptera: Braconidae) revealed a host range restricted to Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) and C. doddi. Field collections of cactophagous larvae parasitized by the congeneric and sympatric parasitoid A. alexanderi included the host species C. bucyrus, Sigelgaita nr. chilensis, Tucumania sp., Tucumania tapiacola and Salambona sp. If a narrow host range for A.opuntiarum is confirmed in quarantine with North American cactus-feeding species, then this parasitoid could be released as a biological control agent for C. cactorum with little or no risk to non-target species.Las exploraciones de campo en Argentina de larvas hospedadoras cactófagas parasitadas por Apanteles opuntiarum Martínez & Berta (Hymenoptera: Braconidae), un bracónido recientemente descripto, revelaron un espectro de hospedadores restringido a Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) y C. doddi. Las colecciones de campo de larvas cactófagas parasitadas por la especie congenérica y simpátrica A. alexanderi identificaron a C. bucyrus, Sigelgaita nr. chilensis, Tucumania sp., Tucumania tapiacola y Salambona sp. como especies hospedadoras. Si se confirma en cuarentena el estrecho rango de hospedadores de A. opuntiarum sobre especies norteamericanas que se alimentan de cactus, podría ser liberado como agente de control biológico de C. cactorum, con bajo riesgo o ninguno a especies no blanco.Fil: Varone, Laura. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Logarzo, Guillermo Alejandro. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Martinez, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Navarro, Fernando. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; ArgentinaFil: Carpenter, James E.. United States Department of Agriculture; Estados UnidosFil: Hight, Stephen D.. United States Department of Agriculture; Estados Unido
Effects of biceps tension and superior humeral head translation on the glenoid labrum
We sought to understand the effects of superior humeral head translation and load of the long head of biceps on the pathomechanics of the superior glenoid labrum by predicting labral strain. Using micro‐CT cadaver images, a finite element model of the glenohumeral joint was generated, consisting of humerus, glenoid bone, cartilages, labrum, and biceps tendon. A glenohumeral compression of 50 N and biceps tensions of 0, 22, 55, and 88 N were applied. The humeral head was superiorly translated from 0 to 5 mm in 1‐mm increments. The highest labral strain occurred at the interface with the glenoid cartilage and bone beneath the origin of the biceps tendon. The maximum strain was lower than the reported failure strain. The humeral head motion had relatively greater effect than biceps tension on the increasing labral strain. This supports the mechanistic hypothesis that superior labral lesions result mainly from superior migration of the humeral head, but also from biceps tension. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1424–1429, 2014.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108670/1/jor22688.pd
Effects of biceps tension on the torn superior glenoid labrum
The purpose of this study was to evaluate the role of the tension on the long head of the biceps tendon in the propagation of SLAP tears by studying the mechanical behavior of the torn superior glenoid labrum. A previously validated finite element model was extended to include a glenoid labrum with type II SLAP tears of three different sizes. The strain distribution within the torn labral tissue with loading applied to the biceps tendon was investigated and compared to the inact and unloaded conditions. The anterior and posterior edges of each SLAP tear experienced the highest strain in the labrum. Labral strain increased with increasing biceps tension. This effect was stronger in the labrum when the size of the tear exceeded the width of the biceps anchor on the superior labrum. Thus, this study indicates that biceps tension influences the propagation of a SLAP tear more than it does the initiation of a tear. Additionally, it also suggests that the tear size greater than the biceps anchor site as a criterion in determining optimal treatment of a type II SLAP tear. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1545–1551, 2015.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113101/1/jor22888.pd
Geographical Range and Laboratory Studies on Apanteles opuntiarum (Hymenoptera: Braconidae) in Argentina, a Candidate for Biological Control of Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America
La polilla de la tuna, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), es una plaga que amenaza las Opuntia spp. nativas de América del Norte. Se han implementado varias estrategias para su control, erradicándola de México pero no de los Estados Unidos, donde ha continuado incrementando su distribución geográfica con éxito. Por lo tanto, se propone un enfoque integrado que incluya al control biológico para regular las poblaciones de C. cactorum en América del Norte. Se realizaron relevamientos de campo del parasitoide recientemente descrito, Apanteles opuntiarum Martínez & Berta, dentro del área de distribución nativa de C. cactorum en Argentina, y se realizaron estudios de laboratorio para desarrollar un protocolo de cría del parasitoide. Apanteles opuntiarum fue el parasitoide más común de C. cactorum y sus distribuciones en el campo coincidieron ampliamente. En el laboratorio, el éxito reproductivo del parasitoide se maximizó cuando una o dos avispas estuvieron expuestas a 30 larvas dentro de un recipiente de 500 ml. Hembras criadas en laboratorio fueron menos exitosas parasitando hospedadores que hembras provenientes del campo. A pesar del éxito logrado en la cría de los parasitoides, obtuvimos una proporción de sexos sesgada hacia machos en los experimentos. Como este sesgo podría estar relacionado a la presencia del parásito reproductivo Wolbachia, tanto la colonia de laboratorio como individuos provenientes del campo fueron analizados y poseían Wolbachia. El presente estudio proporcionó información útil de campo y laboratorio para (1) estandarizar una técnica de cría en laboratorio; (2) realizar estudios de especificidad de hospedadores en condiciones de cuarentena; y (3) seleccionar las poblaciones de parasitoides que mejor coinciden con el clima de las áreas invadidas por C. cactorum en América del Norte.The cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), is a pest that threatens native Opuntia spp. in North America. Control tactics developed and implemented against this invasive pest successfully eradicated the moth in Mexico and on barrier islands in the United States. However, with the cancellation of the regional management program in the United States, no control tactics are being implemented to mitigate the expansion of the moth's geographical range. Hence, an integrated approach including biological control is proposed to regulate the population of C. cactorum in North America. Field surveys of the recently described parasitoid, Apanteles opuntiarum Martínez & Berta, were carried out within the C. cactorum native range in Argentina, and laboratory studies were conducted to develop a parasitoid rearing protocol. Apanteles opuntiarum was the most common parasitoid of C. cactorum and their field distributions were similar. In the laboratory, the parasitoid's reproductive success was maximized when one or two female wasps were exposed to 30 host larvae within a 500 ml container. Laboratory reared females were less successful at parasitizing hosts than field collected females. In spite of the success achieved with laboratory rearing, male bias was observed throughout the experiments. Because this bias might be related to the presence of the reproductive parasite Wolbachia, both laboratory colony and field collected individuals were screened and Wolbachia was detected. This study provides useful field and laboratory information on (1) laboratory rearing techniques for A. opuntiarum; (2) developing host specificity test protocols for studies under quarantine conditions; and (3) selecting parasitoid populations that best match the climatic conditions present in the C. cactorum invaded areas of North America.Fil: Mengoni Goñalons, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Varone, Laura. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Logarzo, Guillermo Alejandro. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Guala, Mariel. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Rodriguero, Marcela Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Hight, Stephen D.. United States Department Of Agriculture. Agriculture Research Service; Estados UnidosFil: Carpenter, James E.. United States Department Of Agriculture. Agriculture Research Service; Estados Unido
The phylogeny of the social wasp subfamily Polistinae: evidence from microsatellite flanking sequences, mitochondrial COI sequence, and morphological characters
BACKGROUND: Social wasps in the subfamily Polistinae (Hymenoptera: Vespidae) have been important in studies of the evolution of sociality, kin selection, and within colony conflicts of interest. These studies have generally been conducted within species, because a resolved phylogeny among species is lacking. We used nuclear DNA microsatellite flanking sequences, mitochondrial COI sequence, and morphological characters to generate a phylogeny for the Polistinae (Hymenoptera) using 69 species. RESULTS: Our phylogeny is largely concordant with previous phylogenies at higher levels, and is more resolved at the species level. Our results support the monophyly of the New World subgenera of Polistini, while the Old World subgenera are a paraphyletic group. All genera for which we had more than one exemplar were supported as monophyletic except Polybia which is not resolved, and may be paraphyletic. CONCLUSION: The combination of DNA sequences from flanks of microsatellite repeats with mtCOI sequences and morphological characters proved to be useful characters establishing relationships among the different subgenera and species of the Polistini. This is the first detailed hypothesis for the species of this important group
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