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161.
JOSÉ F. GÓMEZ JOSÉ LUIS NIEVES‐ALDREY MARÍA HERNÁNDEZ NIEVES 《Zoological Journal of the Linnean Society》2008,154(4):676-721
We present a phylogenetic and taxonomic study of the morphology and biology of the terminal‐instar larval stage of 19 species representing all the genera of Torymidae parasitoids of gall wasps in Europe, with the single exception of Megastigmus. The genera studied include Adontomerus Nikol'skaya, Idiomacromerus Crawford, Chalcimerus Steffan & Andriescu, Glyphomerus Förster, Pseudotorymus Masi and Torymus Dalman. We primarily used chaetotaxy and some head structures. The terminal‐instar larvae of all studied species are thoroughly described for the first time and illustrated with SEM images. We provide diagnostic characters for the family and the genera studied, and keys to genera and species for the identification of torymid larvae associated with cynipid galls. The majority of the torymid larvae studied are solitary monophagous parasitoids. Finally, to assess the potential use of larval characters in systematic studies of the family, a phylogenetic analysis of the studied taxa based on 42 larval morphological characters is proposed and compared with the current taxonomy of Torymidae. Our results suggest that body chaetotaxy, and characters of the head and mouthparts could be used for genera and species discrimination. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 676–721. 相似文献
162.
FERNANDO MENDONÇA D'HORTA JOSÉ MARIA CARDOSO DA SILVA CAMILA CHEREM RIBAS 《Biological journal of the Linnean Society. Linnean Society of London》2008,95(3):583-597
One of the best examples of differentiation and hybridization among South American passerine birds is exhibited by Icterus cayanensis (Epaulet Oriole) and Icterus chrysocephalus (Moriche Oriole). Icterus chrysocephalus is a monotypic species restricted to northern South America. Icterus cayanensis is a polytypc species that ranges from Suriname and French Guyana to northern Argentina. Five subspecies are recognized to I. cayanensis. Hybrid zones are known between I. cayanensis and I. chrysocephalus as well as between subspecies of I. cayanenis, even though character variation has never been adequately assessed and mapped. Although molecular data support the hypothesis that I. cayanensis and I. chrysocephalus form a monophyletic group, they do not support the species limits currently recognized within this group. We analysed the geographic variation of plumage characters along the range of this group to map the geographic variation of individual plumage characters and identify the populations that have uniform phenotypic character expression and therefore represent genuine phylogenetic species. We also used molecular data to investigate the phylogenetic relationships among these species. Geographic variation of plumage characters, habitat preferences and molecular data identified four species within I. cayanensis–chrysocephalus clade: an Amazonian species group, formed by I. cayanensis and I. chrysocephalus and a Southern species group composed of I. pyrrhopterus and I. tibialis. The Amazonian species are separated by a relatively narrow hybrid zone along the Amazon valley, whereas the Southern species are separated by a hybrid zone that is larger than the ranges of the two species individually. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 583–597. 相似文献
163.
Éva Hideg 《Central European Journal of Biology》2008,3(3):273-284
Four fluorescent singlet oxygen sensors: DanePy, its oxalate salt, Singlet Oxygen Sensor Green and MVP, were infiltrated into
tobacco leaves and tested for toxicity, subcellular localization, light sensitivity and capacity to trap the singlet oxygen
produced in photoinhibition. For reference, a broad sensitivity free radical probe, TEMPO-9-AC, was also included. Photochemical
yield was approximately 15% and 10% inhibited by Singlet Oxygen Sensor Green and MVP, respectively, but was not significantly
affected by the other probes. Under photoinhibitory conditions, brought about by irradiating lincomycin-treated leaves with
strong photosynthetically active radiation, DanePy and Singlet Oxygen Sensor Green were responsive. Singlet Oxygen Sensor
Green was also reactive to low, non-photoinhibitory light exposure of the leaf, which was not characteristic to the other
probes. MVP did not respond to singlet oxygen which can partly be explained by a possible attenuation of its blue emission
in the leaf, as shown by the example TEMPO-9-AC. DanePy-oxalate did not respond to photosynthetic singlet oxygen due to lack
of its penetration into photosynthetic tissue and hence could be useful in detecting any singlet oxygen which escapes from
a chloroplast initiation site. DanePy was localized in the chloroplasts, while Singlet Oxygen Sensor Green was mainly found
in the epidermal cells preferentially associated with the nucleus.
相似文献
164.
This paper reports on the most important non-timber forest products (NTFPs) marketed and used during the dry season in Cinzana, near Ségou, Mali. Data was gathered from villagers through market surveys and interviews with vendors, buyers, and key informants in traditional medicine. In the Sudano-sahelian agricultural region, NTFPs are collected from parklands, comprising of fallows and croplands. Of the 20 species, five were used in handicraft production, 11 yielded human foods, and 11 had medicinal uses. In addition, many tree species have multipurpose value: six of the 20 species were recorded to be food producers in addition to having uses for handicraft production and/or medicine. The contribution of herbaceous species to the NTFPs used and harvested during the dry season is negligible. Only one of the species was non-ligneous, indicating the large significance of tree species for local communities in a region with long seasonal dry periods. 相似文献
165.
Chlorophyll-a content is widely used as an indicator of the quality of freshwater bodies. Quantification of chlorophyll-a is a routine procedure in the test laboratories of water works, and in research laboratories. Although attempts have been made to standardise the measurement procedure, there are nonetheless many procedures currently in use. This work is focused on a careful re-examination of the ISO: 10260, 1992 standard, which prescribes 90% (v/v) ethanol for chlorophyll extraction and measurement. Chlorophyll contents of cultures of the cyanobacterium Synechococcus elongatus Nägeli and the chlorophyte Scenedesmus acutus Meyen were determined by means of a series of concentrations of ethanol/water mixtures which were employed as extracting agents – the water content was gradually decreased from 20 to 0%. The extraction procedure was verified by measuring the amount of retained water after using both water and oil pumps for filtering the samples. The spectroscopic effects of the presence of water were studied and the molecular background of these spectral phenomena is discussed. The extraction yields obtained with 90% ethanol were compared to those obtained with methanol and acetone. On the basis of the calculated error level, improvements to the ISO: 10260, 1992 standard method have been suggested. 相似文献
166.
B. A. Harutiunian-Kozak D. L. Khachvankyan A. A. Ékimyan J. A. Kozak L. V. Martirosyan Z. A. Vagramyan É. G. Bagdasaryan 《Neurophysiology》2002,34(6):406-415
On cats with pretrigeminal brainstem transection, we studied the properties of visually sensitive neurons of the extrastriate associative cortical area 21b. The dimensions and spatial distribution of the receptive fields (RF) of the neurons within the vision field were determined. It was found that large-sized RF prevailed within the area 21b (10 to 200 deg2, 61%; greater than 200 deg2, 22%), whereas small-sized RF (1 to 10 deg2) constituted 17% of all the studied RF. Stationary visual stimuli evoked on–off, off, and on responses in 43, 30, and 27% neurons of the area 21b, respectively. In the cases where moving stimuli were presented, 35% of the neurons demonstrated directional sensitivity; the rest of the neurons (65%) were directionally insensitive. We also found a group of neurons that were capable of differentiating not only the direction of the stimulus movement along the RF but also the dimension, shape, and orientation of a complicated moving stimulus. Taking into account the data obtained, we discuss the functional role of the neurons, which demonstrated a specific (specialized with respect to a set of the parameters of visual stimulus, and not to a single parameter) response in central processing of the sensory information. 相似文献
167.
Altitudinal distribution limits of aquatic macroinvertebrates: an experimental test in a tropical alpine stream 下载免费PDF全文
PHILIP B. MADSEN ANDRÉS MORABOWEN PATRICIO ANDINO RODRIGO ESPINOSA SOPHIE CAUVY‐FRAUNIÉ OLIVIER DANGLES DEAN JACOBSEN 《Ecological Entomology》2015,40(5):629-638
1. Temperature and oxygen are recognised as the main drivers of altitudinal limits of species distributions. However, the two factors are linked, and both decrease with altitude, why their effects are difficult to disentangle. 2. This was experimentally addressed using aquatic macroinvertebrates; larvae of Andesiops (Ephemeroptera), Claudioperla, (Plecoptera), Scirtes (Coleoptera) and Anomalocosmoecus (Trichoptera), and the amphipod Hyalella in an Ecuadorian glacier‐fed stream (4100–4500 m a.s.l.). The following were performed: (i) quantitative benthic sampling at three sites to determine altitudinal patterns in population densities, (ii) transplants of the five taxa upstream of their natural altitudinal limit to test the short‐term (14 days) effect on survival, and (iii) in situ experiments of locomotory activity as a proxy for animal response to relatively small differences in temperature (5 °C vs. 10 °C) and oxygen saturation (55% vs. 62%). 3. The transplant experiment reduced survival to a varying degree among taxa, but Claudioperla survived well at a site where it did not naturally occur. In the in situ experiment, Scirtes and Hyalella decreased their activity at lower oxygen saturation, whereas Andesiops and Anomalocosmoecus did so at a low temperature. The decrease in activity from a high to a low temperature and oxygen for the five taxa was significantly correlated with their mortality in the transplant experiment. 4. Together the present experiments indicate that even relatively small differences in temperature and oxygen may produce effects explaining ecological patterns, and depending on the taxon, either water temperature or oxygen saturation, without clear interacting effects, are important drivers of altitudinal limits. 相似文献
168.
169.
ENRIQUE JHONATAN ROMO-MARTÍNEZ GABRIELA MARTÍNEZ-CORTÉS REYNA LUCÍA BARAJAS-TORRES RODRIGO RUBI-CASTELLANOS MARÍA TERESA MAGAÑA-TORRES HÉCTOR RANGEL-VILLALOBOS JUAN RAMÓN GONZÁLEZ-GARCÍA 《Journal of genetics》2012,91(3):297-302
Morphological variation of the Y chromosome has been observed in different populations. This variation is mostly related to the heteromorphic Yq12 band, which is composed of a variable block of constitutive heterochromatin. The Yqh+ heteromorphism has a worldwide frequency of 2.85% and is considered clinically innocuous. The aim of this study was to identify the ancestry of the Yqh+ heteromorphism present in individuals from western Mexico. For this purpose, 17 Y-chromosome single nucleotide polymorphisms were analysed by multiplex polymerase chain reaction and SNaPshot assays. In 28 Yqh+ males, only five haplogroups were observed; with a haplogroup diversity of 0.4841 ± 0.1094, which was less than that observed in a study of unselected Mexican mestizo population. Differences were specifically conferred by the high frequencies of haplogroups R1b1 and P*(xQ,R), and by the absence of the Amerindian haplogroup Q (Q*(xQ1a3a) plus Q1a3a) from the Yqh+ group. This study suggests a post-1492 incorporation for Yqh+ chromosomes into the Mexican northwestern population. 相似文献