INTROGRESSING PHEROMONE QTL BETWEEN SPECIES: TOWARDS AN EVOLUTIONARY UNDERSTANDING OF DIFFERENTIATION IN SEXUAL COMMUNICATION

As a first step toward understanding how noctuid moths evolve species-specific pheromone communication systems, we hybridized and backcrossed two closely related moth species, Heliothis virescens (Hv) and H. subflexa (Hs), which differ qualitatively and quantitatively in their multi-component sex pheromone blends. We used amplified fragment length polymorphism (AFLP) marker-based mapping of backcross families to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the percentages of specific chemical components in the pheromone blends. In two previous backcrosses to Hs, we found a strong depressive effect of Hv-chromosome 22 on the percentage of three acetate components in the pheromone gland. These acetates are present in Hs and absent in Hv. Here, we describe how we introgressed Hv-chromosome 22 into the genomic background of Hs. Selection for Hv-chromosome 22 started from backcross 3 (BC₃) females. All females that had Hv-chromosome 22 and a low percentage of acetates (< 3% of the total amount of pheromone components present) were backcrossed to Hs males. In BC₅ to BC₈, we determined whether Hv-chromosome 22 was present by a) running only the primer pairs that would yield the markers for that chromosome, and/or b) determining the relative percentages of acetates in the pheromone glands. Either or both genotype and phenotype were used as a criterion to continue to backcross these females to Hs males. In BC₉, we confirmed the isolation of Hv-chromosome 22 in the Hs genomic background, and backcrossed the males to Hs females to eliminate the Hv-sex chromosome as well as mitochondrial DNA. The pheromone composition was determined in BC₃, BC₅, and BC₁₁ females with and without Hv-chromosome 22. All backcross females with Hv-chromosome 22 contained significantly less acetates than females without this chromosome. In addition, BC₃ females with Hv-chromosome 22 contained significantly more Z11-16:OH than BC₃ females without Hv-chromosome 22. However, in BC₅ and BC₁₁ females, the correlation between Z11-16:OH and Hv-chromosome 22 was lost, suggesting that there are separate QTL for the acetates and for Z11-16:OH, and that the relative amount of the alcohol component is only affected in epistasis with other (minor) QTL. Now that we have succeeded in isolating the chromosome that has a major effect on acetate production, we can test in behavioral experiments whether the presence of acetates may have been a driving force for a shift in pheromone composition. Such tests are necessary to move towards an evolutionary understanding of the differentiation in sexual communication in Heliothis spp. moths.     

高合金不锈钢在降膜板式蒸发器上的应用

外流降膜板式蒸发器作为替代列管式蒸发器的新设备应用于氧化铝行业,其板片材质处于一个摸索选择的过程。本文就高合金不锈钢板片的失败事例进行分析,通过试验、试用,最终找到较为理想的材质。     

System identification using almost periodic functions: application to non-linearities with memory

A method for measuring by crosscorrelation the impulse responses of the linear portions of a system containing a zero-memory non-linearity is shown to be applicable to certain typos of non-linear characteristic with memory. Several situations are analysed and some experimental results presented. A computer programme is given for calculating the parameters of the input signal from a given tabulated non-linear characteristic.     

Fire detection using data from the NOAA-N satellites

Abstract

Due to increased concern over the climatic and economic impact of fires associated with deforestation and seasonal burning, most of which occurs in remote parts of the worid, it is necessary to find ways to effectively monitor such activity. The 3.8μm channel on board the National Oceanic and Atmospheric Administration's polar-orbiting satellites is very sensitive to high temperature sources such as fires. Case studies in Mexico, Brazil, Mozambique and the Soviet Union have been selected to demonstrate the utility of this channel for fire detection. With the fire detection capability of the 3.8 μm channel and the daily global coverage, it is possible to monitor world-wide fire activity.     

Radiometric comparison of the LANDSAT-5 TM and MSS sensors

Abstract

This paper analyses the radiometric accuracy of LANDSAT-5 Thematic Mapper (TM) data and of LANDSAT-5 Multispectral Scanner (MSS) data, using concurrent TM and MSS images recorded simultaneously over the city of Montreal, Quebec, Canada. The data sets were obtained from the Canada Centre for Remote Sensing (CCRS), and have been preprocessed for geometric correction, and for radiometric 23calibration utilizing the in-flight calibration lamp data. The comparison of the TM and MSS normalized apparent reflectances computed for 12 different typical cover types using the post-launch calibration dynamic ranges shows the relevance of the CCRS processing systems. The significant linear regressions, obtained between channels from the two sensors, and the analysis of the ground reflectance corrected for atmospheric absorption and scattering as well as for pixel adjacency effects, can serve both to assess detector degradation with time and to rescale data to match those from other LANDSAT sensors.     

Dyadic output feedback laws generated as Kronecker products : optimal and suboptimal solutions

The problem of eigenvalue assignment in the system dx/dt equals; Ax + Bu, y = Dx, using the dyadic output feedback law u = u₀ + q · p^Ty is considered via a formulation developed earlier by the author, in which p and q occur in the Kronecker product vector p?q. The equations governing the values of p and q which give an optimum approximation to a prescribed spectrum of eigenvalues are derived, and a special case is solved. Various facets of the problem of generating suboptimal solutions are discussed.     

技术改造项目的技术经济评价方法

分析比较了技术改造项目的经济评价的计算方法，利用“有无比较法”计算增量净收益，是技术改造项目经济效益计算的有效方法。     

铁谱技术及综合诊断技术的应用

介绍了铁谱技术在设备工监测中的应用及主要监测原理，针对应用实践中存在的问题，对多种监测技术相结合的综合诊断方法进行了探讨。     

Turkish kefir and kefir grains: microbial enumeration and electron microscobic observation†

Microbial populations in kefir and kefir grains were enumerated by plating. Total lactic acid bacteria, lactoccocci, lactobacilli and yeast populations increased during fermentation and increased slightly during cold storage. Kefir grains had a lactic acid bacteria : yeast ratio of 10 ⁹  : 10 ⁶ . In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods, which indicated yeast colonization on the surface and middle part of the kefir grain. Three types of lactobacilli (short, long and curved) were noted throughout the grain. Lactococci were not observed under SEM; preparation of kefir grains for SEM may have caused removal of lactococci from the grains.