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71.
Ayuka T. Fombong Jacqueline M. Mutunga Peter E. A. Teal Baldwyn Torto 《Journal of chemical ecology》2016,42(10):1063-1069
The Afro-tropical scarab Oplostomus haroldi (Witte) is a pest of honeybees in East Africa with little information available on its chemical ecology. Recently, we identified a female-produced contact sex pheromone, (Z)-9-pentacosene, from the cuticular lipids that attracted males. Here, we investigated the kairomonal basis of host location in O. haroldi. We used coupled gas chromatography/electroantennographic detection (GC/EAD) and GC/mass spectrometry to identify antennally-active compounds from volatiles collected from honeybee colonies. Antennae of both sexes of the beetle consistently detected seven components, which were identified as 3-hydroxy-2-butanone, 2,3-butanediol, butyl acetate, isopentyl acetate, butyl butyrate, hexyl acetate, and methyl benzoate. In olfactometer bioassays, both sexes responded to the full seven-component synthetic blend over solvent controls, but chose honeybee colony odors over the blend. These findings suggest that the seven compounds are components of a kairomone from honeybee colonies used by O. haroldi. 相似文献
72.
This report is similar to previous ones on educational facilities and financial assistance for graduate students in psychology. Institutions with graduate programs in psychology are listed, with information supplied by the respective departments. There is no evaluation of these programs and no implication of approval of them by the American Psychological Association, except those doctoral programs in clinical psychology and in counseling psychology that are indicated by the phrase, "PhD in clinical and counseling APA-approved." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
73.
The formation of cokes and graphites proceeds via the creation from the isotropic fluid phase of carbonization of pitch and coal, of lamellar nematic liquid crystals or mesophase. This anisotropic fluid, deformable mesophase, develops as spheres within which constituent molecules are stacked parallel to an equatiorial plane. This type of structure facilitates coalescence to a coherent mass which eventually forms a graphitisable carbon. The ‘onion-skin’ structure of mesophase spheres cannot so coalesce. Different optical textures of cokes and graphites owe their origin to different chemical reactivities and fluidities of mesophase, the lower the fluidity the smaller the size of the optical texture. Mesophase from lameller molecules is compared with conventional rod-like nematic liquid crystals. Structures in needle-cokes, metallurgical coke, coke from solvent refiend coal and carbon fibre from pitch are discussed in terms of formation and properties of lamellar nematic liquid crystals. 相似文献
74.
A subnanosecond voltage generator has been used to measure the zero-strain electro-optic coefficient r63? of KD*P, and a value of 24.0×10?12 m/V±5% has been obtained. 相似文献
75.
Pulsed-laser damage in XDP electro-optic crystals, occurring at energy densities ? 2J/cm2, has been related to the presence of micrometer-sized inclusions. For material free of these inclusions damage occurs by self-focusing mechanisms at power densities of approximately 20GW/cm2. 相似文献
76.
A 3-port unit that satisfies the requirements of the circulator concept is realised with a differential-input operational amplifier. It provides, between two of its ports, a direct measure of reflection coefficient at the third port. One unit may be employed as a hybrid transformer; two or more units may be connected in a ring to form an n-port circulator. 相似文献
77.
Male and female weanling rats were fed diets containing 2 or 42% of calories as corn oil or 40% as beef tallow plus 2% as
corn oil until they were 12 or 18 weeks of age. Incorporation of C14-acetate into lipids of serum and liver and concentration of lipids in serum, liver, and carcass at the end of these periods
were determined.
Net synthesis of noncholesterol lipid was repressed by changing the diet from 2% to 42% of calories from either dietary fat
in both sexes and at both ages. Cholesterol net synthesis was enhanced 29-fold in males and 22-fold in females fed 42% corn
oil compared to 2% corn oil to the age of 12 weeks. It was enhanced only 2.6-fold for males and 3.4-fold for females by 40%
beef tallow plus 2% corn oil. At 18 weeks of age cholesterol synthesis in males fed 42% corn oil was 7.3 and in females 9.1
times the value for those fed 2% corn oil. At this age the values for rats fed 40% beef tallow plus 2% corn oil were 1.2 and
3.7 times those for 2% corn oil fed rats of the respective sexes. 相似文献
78.
Ideal 2-port invertor network realisations are given in tabulated form, using one basic network topology. The B and C elements of the transmission matrix T (T=A, B; C, D) representing these invertors are controlled independently and can be real, imaginary or complex. 相似文献
79.
80.