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1.
Among non-canonical DNA secondary structures, G-quadruplexes are currently widely studied because of their probable involvement in many pivotal biological roles, and for their potential use in nanotechnology. The overall quadruplex scaffold can exhibit several morphologies through intramolecular or intermolecular organization of G-rich oligodeoxyribonucleic acid strands. In particular, several G-rich strands can form higher order assemblies by multimerization between several G-quadruplex units. Here, we report on the identification of a novel dimerization pathway. Our Nuclear magnetic resonance, circular dichroism, UV, gel electrophoresis and mass spectrometry studies on the DNA sequence dCGGTGGT demonstrate that this sequence forms an octamer when annealed in presence of K(+) or NH(4)(+) ions, through the 5'-5' stacking of two tetramolecular G-quadruplex subunits via unusual G(:C):G(:C):G(:C):G(:C) octads.  相似文献   

2.
With the aim of identifying the species of nasal mites of Paroaria coronata (red-crested cardinal), the nasal cavity of 40 birds were examined. The nasal mites were identified as Ptilonyssus sairae de Castro and Sternostoma pirangae Pence, with 50% and 7.5% of prevalence, respectively. This is the first record of these mite species parasitizing P. coronata. This report also amplifies the area of occurrence of S. pirangae for Brazil and that of P. sairae for Rio Grande do Sul, Brazil.  相似文献   

3.
The interaction between Acarophenax lacunatus (Cross & Krantz) and Anisopteromalus calandrae (Howard) may be a promising tool for the integrated pest management of stored grain insect pests. The objective of this study was to evaluate the compatibility of these two natural enemies on Rhyzopertha dominica (Fabricius). The experimental units were petri dishes (140 x 10 mm) containing 30 g of whole wheat grains (13% water content) infested with 20 adults of R. dominica. The treatments consisted of inoculation of A. lacunatus and A. calandrae, separately and associated, in eight replicates. Three inoculations of five adult females of the natural enemies were carried out in each petri dish at five, ten and fifteen days after the infestation of R. dominica. All treatments were stored during 60 days in environmental chamber at 30 +/- 1 degrees C, 60 +/- 5% relative humidity and 24 h scotophase. The smallest numbers of physogastric females of A. lacunatus and of adults of A. calandrae were obtained when the natural enemies were in association. The use of A. calandrae alone demonstrated a low instantaneous rate of increase (r(i)) of R. dominica and a high protection of the wheat grains. The association of A. calandrae with A. lacunatus led to the lowest number of immatures of R. dominica. These results demonstrate the importance of this interaction as a tool of for the integrated management of R. dominica in stored wheat grains.  相似文献   

4.
The aim of the present study was to assess the effect of six different temperatures on the development of Acarophenax lacunatus (Cross & Krantz) using eggs of Tribolium castaneum (Herbst) and Cryptolestes ferrugineus (Stephens) as hosts. The temperature affected the development of A. lacunatus. The largest values for the progeny (19 mites in T. castaneum and 15 mites in C. ferrugineus) were obtained at about 30 degrees C, as also observed for the net reproductive rate (Ro), which revealed that the A. lacunatus population increased 18 times in T. castaneum and 14 times in C. ferrugineus in a generation. The intrinsic rate of increase (r m) gradually increased with temperature, reaching the maximum value at 35 degrees C in T. castaneum (1,608) and C. ferrugineus (1,289). The generation time was negatively correlated with temperature, ranging from 1,60 to 4,85 days in T. castaneum and from 1,96 to 5,34 days in C. ferrugineus. These results suggest that the mite A. lacunatus may be used in programs of biological control of T. castaneum and C. ferrugineus in the tropics.  相似文献   

5.
The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.  相似文献   

6.
We first record Carcinops troglodytes (Paykull) as a predator of Alphitobius diaperinus (Panzer) larvae in poultry houses in North and Northwest regions of the state of Paraná. Carcinops spp. are commonly recorded as predators of dipterans, and this record in poultry houses indicates the possibility of exploiting such predator for future studies aiming the development of management strategies for A. diaperinus.  相似文献   

7.
小黑瓢虫对高氏瘤粉虱捕食作用的研究   总被引:6,自引:1,他引:5  
在高氏瘤粉虱不同虫态共存的条件下,小黑标虫对高氏瘤粉虱各虫态的选择次序为卵>1龄若虫>2龄若虫>3龄若虫>4龄若虫和拟蛹,对卵的捕食率均最高,有明显的嗜好选择;小黑瓢虫幼虫捕食粉虱卵的数量,随着龄期的增长而递增,其中4龄幼虫的捕食量最大,4龄期捕食量平均为1565.42粒,占全幼虫期总食卵量的45.42%,整个幼虫期可捕食高氏瘤粉虱的卵数平均为3446.5粒。小黑瓢虫3龄幼虫对粉虱卵的捕食作用率在所给的猎物密度(1500粒/皿)条件下,随着自身密度的增加而降低。  相似文献   

8.
Eight specimens of Sericolophus reflexus (Ijima) were compared with the holotype of Hernandeziana ijimae (Hernandez) to assess suspected synonymy of these taxa. An extensive morphometric analysis of the spicules available in these specimens of variable condition show that the H. ijimae holotype exhibits characters near the centre of the range of S. reflexus. It is concluded that H. ijimae is a junior synonym of S. reflexus , and that the family Corythophoridae de Laubenfels is invalid by preoccupation of its base generic name.  相似文献   

9.
Two aleocharine species, Autalia rivularis (Gravenhorst) and Brachida clara (Weise), are identified for the first time in Korea. Diagnoses, habitus illustrations, and line drawings of diagnostic characters are provided.  相似文献   

10.
A cladistic analysis of Simulium ( Trichodagmia ) sensu Crosskey and Howard, using 34 morphological characters of larvae (6 characters), pupa (5) and adults (23), yields nine most parsimonious trees under equal weights (length 101 steps CI 0.49 RI 0.73). Successive weighting based on the maximal rescaled consistency index preferred one of the nine (31.37 steps CI 0.62 RI 0.87 total fitcon3= 235.8), which was also one of two trees found under implicit weights with concavity values of 3–6. The cladogram justifies the recognition of two subgenera. Simulium ( Trichodagmia ) sensu stricto (containing S. muiscorum, sumapazense, S. wygodzinskyorum, S. nigrimanum, S. chalcocoma, S. huairayacu and S. lahillei ) is supported by the branchial tip sclerotization and the presence of cibarial teeth, larval body tegument covered with lanceolate hairs, female with simple claw, and gonapophysis size. Simulium ( Thyrsopelma ) (containing S. scutistriatum, S. hirtipupa, S. orbitale, S. guianense, S. perplexum and S. itaunense ) is supported by the hypostomial teeth.  相似文献   

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