商业智能 职业发展新蓝海

读了贵刊上期《商业智能进入人才储备期》一文,感觉自己的职业发展又多了一条道路。     

Multiplex qualitative PCR assay for identification of genetically modified canola events and real-time event-specific PCR assay for quantification of the GT73 canola event

Genetically modified (GM) canola is the most widely grown oilseed crop in Canada. At this time, commercially produced GM canola cultivars in Canada have the events GT73/RT73 and Ms8xRf3. Commercial seed sale of canola cultivars containing the GM events such as OXY235 and T45 has been discontinued. Adventitious presence of GM seeds and grains in non-GM grains is a concern for international grain trade, and development of effective detection methods is important. A multiplex qualitative PCR procedure was established for the detection of the GM canola events OXY235, Ms8xRf3, T45 and GT73. The presence of the GM canola events was also successfully detected in ground spiked wheat and barley grain samples prepared at 0.1%, 0.5% and 1.0% levels (w/w). The GT73 real-time PCR assay was successfully used to quantify DNA extracted from spiked ground canola samples consisting of 5%, 1%, 0.5% and 0.1% GT73 (w/w).     

Development of a polymerase chain reaction assay for detection of three canola transgenes

Many countries are developing or implementing regulatory requirements to monitor for the presence of genetically modified (GM) materials in seeds, grain, and derived food products using DNA and protein-based methods. There is no published report on the detection of different GM transgenes in canola, and this study is aimed at developing qualitative PCR methods for the three major GM transgenes commercially available in canola. Primer sequences were generated from Gen-Bank and previously published information to develop a polymerase chain reaction (PCR) detection method for Roundup Ready (glyphosate tolerance, GT73 event), Liberty Link (glufosinate ammonium tolerance, HCN92 event), and BX (Bromoxynil tolerance, OXY235 event) canola varieties. On using PCR, two primer pairs for each of the GT73 and HCN92 and one primer pair for OXY235 amplified specific amplicons for the three GM transgenes. All three GM transgenes were detected simultaneously by multiplexing the five primer pairs in a single PCR reaction. Multiplexing of the five primer pairs for DNA prepared at 1% (one GM seed in 99 non-GM seeds) and 0.5% (one GM seed in 199 non-GM seeds) levels generated the expected DNA fragments for GT73, HCN92, and OXY235. This information will lay the groundwork for the development of a quantitative PCR assay for canola transgenic events.     

Oil Content and Fatty Acid Composition of Seeds of Guizotia Cass (Compositae)

Seeds of Guizotia abyssinica and wild Guizotia were analysed for oil content and fatty acid composition by multisequential and gas chromatographic methods, respectively. The oil content of G abyssinica ranged from 416 to 436 g kg^-1 (weight per kg dry matter of seeds) and that of the wild Guizotia taxa from 214 to 328 g kg^-1. Two unsaturated fatty acids (linoleic (54·3–72·8, weight percent of total oil) and oleic (5·4–26·8% of oil by wt) and two saturated fatty acids (palmitic (7·8–10%) and stearic (5·5–8·1%)) were about 91–97% of the fatty acids present. Palmitoleic, linolenic, arachidic, eicosenoic, behenic, erucic and lignoceric acids constituted about 2–3%. An unidentified fatty acid, probably an epoxy form of C: 20 or C: 22, has been found in all the materials and it was 1·1–6·6%. Total saturated and unsaturated fatty acids were about 74–84% and 15–20%, respectively. Differentiation in fatty acid composition between the taxa is too small to be of taxonomic use. It is inferred that when gene transfer is desired hybridisation between the wild and cultivated taxa may not affect the oil quality of the latter and the oils of the wild taxa are possibly safe for human consumption. © 1997 SCI.     

Wheat Starch Modification Through Biotechnology

Natural mutations that affect the amylose/amylopectin ratio in starch are unlikely to develop naturally in wheat due to its allohexaploid genome (2n=6x; AABBDD). One of the strategies to modify wheat starch structure involves identification of germplasms with null alleles for starch biosynthetic genes, followed by exchange of functional alleles with the identified null alleles through classical plant breeding. This technique has successfully been used to combine the three null alleles for granule-bound starch synthase I (GBSSI) to develop a wheat line that produces amylopectin-rich (>95%) starch (waxy starch). Another strategy to alter expression levels of starch biosynthetic genes employs recent advances in molecular biology and genetic engineering of wheat. For this approach, various monocot vectors have been developed that drive expression of wheat starch branching enzyme I (SBEI) cDNA sequences in the anti-sense orientation. Several of the wheat cell lines transformed with the anti-sense vectors express branching enzyme (BE) activity at a significantly lower level than non-transformed cells. One transgenic wheat plant expressing the anti-sense SBEI RNA produces a ten-fold lower level of BE activity in kernels than wild-type wheat. Analysis of starch produced from the transgenic plant shows that starch structure and properties have been altered.     

Comparison and Extension of Existing 3D Propagation Models with Real-World Effects Based on Ray-Tracing

The next generation of cellular network deployment is heterogeneous and temporally changing in order to follow the coverage and capacity needs. Active Antenna Systems allows fast deployment changes by cell shaping and tilt adaptation which have to be controlled in self-organized manner. However, such kind of automated and flexible network operations require a Self Organizing Network (SON) algorithm that works based on network performance parameters being partly derived from the radio measurements. Thus, appropriate radio propagation models are not only needed for network planning tools but also for simulative lab tests of the developed SON algorithm controlling the flexible deployment changes enabled by Active Antenna Systems. In this paper, an extension of the existing 3D propagation model is proposed in order to incorporate the propagation condition variation effects, not considered so far, by changing antenna beam orientation like antenna tilting or when users are distributed in the third dimension (height) in multi-floor scenarios. Ray tracing based generated propagation maps that show the realistic propagation effect are used as 3D real world reference for investigation and model approval.     

Linking farm diversification to household diet diversification: evidence from a sample of Kenyan ultra-poor farmers

Starting with a conceptual framework adapted from Herforth and Harris (2013), we analyzed the nexus between farm production diversification and household diet diversity using data collected in 2011 for evaluation of the welfare and economic impacts of Kenya’s Cash Transfer for Orphans and Vulnerable Children (CT-OVC). We used a sample of 1,353 households drawn from six districts of western Kenya to test the hypotheses that on-farm production diversification correlates with household diet diversification and some production activities have stronger association with diet diversification than others in the context of ultra-poor, labor constrained families living in rural Kenya. Approximately 67 % of the sample households received cash transfers through the CT-OVC programme. Production diversification was positively and significantly associated with household diet diversification, with livestock ownership more strongly correlated than crop production. Poultry production had the most compelling correlation, followed by pulses. In both cases, the association was most plausibly attributed to an income effect rather than production-for-own consumption. These findings suggest that supporting investments in diversified livelihood systems in general and in small livestock assets such as poultry, sheep and goats in particular are viable interventions for the improvement of household food security and nutrition for very poor, marginalized smallholders. Under semi-autarkic smallholder agriculture, a diversification strategy, which integrates crop and livestock production, not only adds value directly via increasing diet diversity and quality and indirectly via income effects but also serves as a risk management instrument, protecting against weather and market shocks, and contributing to biodiversity and sustainable land management.     

Impregnation and Characterization of High Performance Extraction Columns for Separation of Metal Ions

Impregnation behaviors of reverse-phase silica materials and C18-silica HPLC columns were studied using di-(2-ethylhexyl)phosphoric acid (HDEHP) as a model extractant. Initially, the adsorption efficiency of the ligand on different types of bulk particles was investigated using various concentration of HDEHP in different composition of methanol/water mixtures based on a batch technique. Subsequently, impregnation of HPLC columns was performed using the dynamic flow-through technique. The experimental data fitted well to the Langmuir model and the adsorption isotherms from the flow-through experiment were used to prepare extraction columns of different ligand densities. Finally, the impregnated columns were characterized and validated through HPLC separation of the lanthanides.     

Simultaneous detection by PCR of Escherichia coli, Listeria monocytogenes and Salmonella typhimurium in artificially inoculated wheat grain

A multiplex PCR procedure was established to detect Escherichia coli, Listeria monocytogenes and Salmonella typhimurium in artificially inoculated wheat grain. The PCR protocol with an enrichment step successfully detected all three organisms inoculated together in non-autoclaved wheat grain. After a one day enrichment, E. coli, L. monocytogenes and S. typhimurium were detected at levels of 56, 1800 and <54 CFU/mL, respectively, in the initial sample. For L. monocytogenes, an improved detection limit of <62 CFU/mL was achieved using singleplex PCR. For autoclaved wheat grain inoculated with the three bacterial strains individually, a detection limit of 3 CFU/mL was achieved after an enrichment step. The ability to test for the three bacteria simultaneously will save time and increase the ability to assure grain quality.     

Model extraction of micromachined planar inductors implemented on alumina substrate

In this work, the high resistivity material property of Alumina substrate is made into use in order to minimize the substrate loss and thereby rendering of relatively high quality MEMS suspended inductors. The modified \(\pi \)-model is used in order to account the skin effect as well as exploit the frequency-dependent losses in the devices. On-wafer-measurements were made prior to characterization and model extraction. The maximum quality factor achieved is about 37.2 with inductor value 3.98 nH at 1.28 GHz. This result is quite promising and could be further enhanced by increasing the metal thickness.