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991.
H. Chen M. F. Chaudhury A. Sagel P. L. Phillips S. R. Skoda 《Journal of Applied Entomology》2014,138(9):708-714
The New World screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), has been eradicated from North and Central America using the sterile insect technique. This success has been based on mass production of high‐quality screwworms using artificial diets since 1958. Many diet formulations for both larvae and adults have been developed, mainly driven by cost efficiency and material supply. However, only four larval and two adult diet formulations have been applied in the six sterile fly mass production plants in the USA, Mexico and Panama. Herein, we briefly review the history of screwworm diet research and development, introduce the diet formulations used in mass rearing and discuss their advantages and disadvantages in terms of plant application. Finally, we propose future research on screwworm nutrition, potential protein sources, feeding stimulants, further optimization of screwworm formulations and possible methods to reduce the negative qualities of waste generated during the mass production. 相似文献
992.
We analyzed anther development in Amomum villosum Lour. (Zingiberaceae) using the periodic acid-Schiff's technique and Sudan black staining to test for the presence of starch and lipids, respectively. Our analyses showed that microspore mother cells of A. villosum lack typical callose walls, and numerous lipid granules appear in the cells early in development. Some starch granules are present in anther wall cells, but not in tapetal cells. After meiosis, numerous lipid granules remain unchanged in the microspores. During microspore development, some small starch granules first appear in the central cell region, and then the starch granules increase in size. After microspore division, the bicellular pollen grains become filled with starch and lipids, and remain in this state until the pollen grains reach maturity. At anthesis, the anther wall of A. villosum consists of several layers of endothecium cells with an evidently thickened radial wall, and some layers of parenchyma cells containing numerous starch granules. 相似文献
993.
994.
Population level differences in adult body mass emerge in infancy and early childhood: Evidence from a global sample of low and lower‐income countries 下载免费PDF全文
Many studies have linked measures of adult body shape and mass in ancient and contemporary populations to ecogeographical variables such as temperature and latitude. These results tend to support Bergmann's rule, which posits that bodies will be relatively less slender for their height in colder climates and more slender in warmer climates. Less well explored is the ontogeny of these population‐level differences. Here we use data on infants and children from 46 low and lower income countries to test whether children's weight for height is associated with measures of temperature and latitude. We also test the hypothesis that children living in areas with greater pathogen prevalence will be lighter for their height because of life history trade‐offs between investment in immune function and growth. Finally, we test whether population specific adult body mass predicts infant and child body mass, and whether this is independent of ecogeographical variables. Our results show that maximum monthly temperature explains 17% of children's weight for height while adult population‐level body mass explains ~44% (Table 5 ). The measures of pathogen prevalence explain little of the variation in children's body shape (8%; P > 0.05). Our results suggest that population differences are consistent with Bergmann's rule but parental body shape explains more variance. Moreover, these population‐level differences arise early in development, suggesting that any possible environmental influences occur in utero and/or result from epigenetic or population genetic differences. Am J Phys Anthropol 154:232–238, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
995.
M. F. Guerrero‐Molina N. C. Lovaisa S. M. Salazar J. C. Díaz‐Ricci R. O. Pedraza 《Plant biology (Stuttgart, Germany)》2014,16(4):726-731
The elemental composition of strawberry plants (Fragaria ananassa cv. Macarena) inoculated with the plant growth‐promoting bacterium Azospirillum brasilense REC3, and non‐inoculated controls, was studied using scanning electron microscopy (SEM) and energy dispersive X‐ray (EDS) analysis. This allowed simultaneous semi‐quantification of different elements in a small, solid sample. Plants were inoculated and grown hydroponically in 50% or 100% Hoagland solution, corresponding to limited or optimum nutrient medium, respectively. Bacteria‐inoculated plants increased the growth index 45% and 80% compared to controls when grown in 100% and 50% Hoagland solution, respectively. Thus, inoculation with A. brasilense REC3 in a nutrient‐limited medium had the strongest effect in terms of increasing both shoot and root biomass and growth index, as already described for Azospirillum inoculated into nutrient‐poor soils. SEM‐EDS spectra and maps showed the elemental composition and relative distribution of nutrients in strawberry tissues. Leaves contained C, O, N, Na, P, K, Ca and Cu, while roots also had Si and Cl. The organic fraction (C, O and N) accounted for over 96.3% of the total chemical composition; of the mineral fraction, Na had higher accumulation in both leaves and roots. Azospirillum‐inoculated and control plants had similar elemental quantities; however, in bacteria‐inoculated roots, P was significantly increased (34.33%), which constitutes a major benefit for plant nutrition, while Cu content decreased (35.16%). 相似文献
996.
Little is known about the effects of nutrient availability on the growth of Trifolium medium in alkaline soil. In 2010, a pot experiment (10 N, P and K fertiliser treatments) with seeding of T. medium into alkaline soil was performed and emergence of seedlings, survival, aboveground and belowground organs were studied. The positive effects of increased nutrient availability on seedling emergence ranged from 5% in the control to 17% in the high P treatment. The lowest mortality was in treatments with P and K supply and the highest in treatments with N supply, due to the sensitivity of young plants to high N availability. The highest values of most measured aboveground plant traits were recorded in treatments with simultaneous application of N, P and K. There were highly positive effects of P supply alone or in combination with N and K on the development of belowground organs. Taproot length ranged from 11.5 in high N to 40.2 cm in P treatment. There was a negative effect of N application on nodulation, especially in N treatments, where growth of T. medium was limited by insufficient P supply. The number of nodules per plant ranged from 0.8 to 4.5 in the high N and P treatments. As demonstrated in this study, T. medium is a potentially suitable legume for alkaline soils. It requires a relatively high P and K supply as well as moderate mineral N supply to achieve its maximum growth potential. 相似文献
997.
目的:探讨2 型糖尿病Roux-en-Y 胃肠转流术(RYGBP)后早期肠内营养对患者血糖的影响。方法:回顾2011 年7 月至
2012 年7 月我科63 例不同发病年龄、不同病程的2 型糖尿病患者行Roux-en-Y 胃肠转流术(RYGBP)后的恢复情况。共分两组:
A 组为术后完全肠外营养直至胃肠道功能恢复正常的患者;B 组为术后早期开始肠内营养患者。监测两组患者术后3 天至2 周的
血清白蛋白含量、血脂、肠蠕动恢复时间、血糖水平、C 肽水平。结果:A、B 两组术后血清白蛋白含量及血脂水平无显著性差异。B
组患者肠功能恢复时间少于A组,血糖水平下降时间较A 组快,其血糖下降时间与肠功能恢复时间一致,B组血清C肽水平变
化时间较A 组提前。结论:2 型糖尿病胃肠转流术(RYGBP)后早期肠内营养支持可以促进肠道功能恢复,加快血糖水平下降,改
善胰岛调节功能。 相似文献
998.
目的:探讨强化护理措施对胃癌患者术后营养状态的改善作用,为减少术后营养相关并发症的发生提供可借鉴的方法。方法:选择2012年1月-2013年12月在我科实施胃癌手术患者的临床资料进行分析,根据术后营养支持方式的不同,将患者分为早期肠内营养支持组和常规肠内营养组。观察并比较两组患者的生命体征变化、术后肛门排气时间及并发症的发生情况等。结果:强化护理组23例胃癌患者给予术后早期肠内营养治疗后,恢复肛门排气时间为53±7.4 h,经过5±2.1 d的肠内营养后,术后体重增加1.2±0.4 kg,无肠内营养相关并发症发生,肠外营养支持时间明显缩短。结论:本研究显示强化早期肠内营养护理具有迅速改善胃癌病人营养不良状态,减少营养不良相关并发症发生,减轻病人经济负担等优点。 相似文献
999.
Geoffrey Michael Gadd Lynn Ramsay John W Crawford Karl Ritz 《FEMS microbiology letters》2001,204(2):311-316
This work examines nutritional influence on fungal colony growth and biomass distribution in response to toxic metals. In low-substrate solid medium, 0.1 mM Cd, Cu and Zn caused a decrease in radial expansion of both Trichoderma viride and Rhizopus arrhizus. However, as the amount of available carbon source (glucose) increased, the apparent toxicity of the metals decreased. These metals also affected the overall length of the fungal mycelium and branching patterns. In low-nutrient conditions, T. viride showed a decrease in overall mycelial length and number of branches in response to Cu, resulting in an extremely sparsely branched colony. Conversely, although Cd also reduced overall mycelial length to about one-third of the control length, the number of branches decreased only slightly which resulted in a highly branched colony with many aberrant features. Cu and Cd induced similar morphological changes in R. arrhizus. A large-scale mycelial-mapping technique showed that disruption of normal growth by Cu and Cd resulted in altered biomass distribution within the colony. When grown on metal-free low-substrate medium, T. viride showed an even distribution of biomass within the colony with some allocation to the periphery. However, Cu caused most of the biomass to be allocated to the colony periphery, while in the presence of Cd, most biomass was located at the interior of the colony. These results imply that such alterations of growth and resource allocation by Cu and Cd may influence success in locating nutrients as well as survival, and that these metals have individual and specific effects on the growing fungus. 相似文献
1000.
Regulation of macronutrient transport 总被引:4,自引:0,他引:4