Co-existence and traceability of GM and non-GM products in the feed chain

According to the European Regulations (EC) 1829/2003 and 1830/2003, products which are, consist of or contain GMOs should be labelled and traceable in each stage of production, processing and distribution. Only in cases where the GMO level is below 0.9% and this presence is due to accidental contamination or is technically unavoidable, no labelling is required. As it is very unclear how feed manufacturers have implemented these new regulations, a Belgian survey was held to evaluate the current situation at importer and feed production level. Several bottlenecks were encountered, at the level of acquisition of raw materials and at production level, such as carry over of GM with non-GM soy in the production lines. Next to this, some weaknesses in the analysis of GMOs were also revealed.     

A comparison of liquid and gas phase surface preparation of III-V compound semiconductors for atomic layer deposition

Native oxide removal and surface termination of InAs(1 0 0) and InSb(1 0 0) using liquid and gas phase HF chemistries were studied using X-ray photoelectron spectroscopy. Aqueous HF etching removed the native oxides on InAs and produced elemental As, which reoxidized when exposed to air. On InSb the native oxides were not completely removed due to F-termination, which passivated the surface. Gas phase HF etching of InSb native oxide completely removed Sb₂O₅ producing a stoichiometric semiconductor surface terminated by F atoms on primarily In surface sites. On InAs gas phase HF completely removed As₂O₃ producing two surface stoichiometries. For the majority of HF to water molar ratios studied, a stoichiometric bulk metal and an As-rich overlayer were produced. For a lean HF composition, an As-rich bulk metal and In-rich overlayer were produced. Deposition of Al₂O₃ by atomic layer deposition (ALD) at 170 °C directly onto F-terminated InSb produced a chemically sharp Al₂O₃/InSb interface. ALD of Al₂O₃ on an In-rich overlayer on InAs resulted in an interfacial layer containing As-oxide.     

Antibacterial activity of fullerene water suspensions (nC60) is not due to ROS-mediated damage

The cytotoxic and antibacterial properties of nC 60, a buckminsterfullerene water suspension, have been attributed to photocatalytically generated reactive oxygen species (ROS). However, in this work, neither ROS production nor ROS-mediated damage is found in nC 60-exposed bacteria. Furthermore, the colorimetric methods used to evaluate ROS production and damage are confounded by interactions between nC 60 and the reagents, yielding false positives. Instead, we propose that nC 60 exerts ROS-independent oxidative stress, thus reconciling conflicting results in the literature.     

Gender differences relative to smoking behavior and emissions of toxins from mainstream cigarette smoke.

This study examined whether gender differences exist in the exposure to select mainstream cigarette smoke toxins as a result of differences in smoking behavior or type of cigarettes smoked among 129 female and 128 male smokers. Smoking topography data indicated that, compared with men, women took smaller puffs (37.6 ml/puff vs. 45.8 ml/puff; p = .0001) of shorter duration (1.33 s/puff vs. 1.48 s/puff; p = .002) but drew more puffs per cigarette (13.5 vs. 12.0; p = .001) and left longer butts (36.3 mm or 40.2% of cigarette length vs. 34.3 mm or 39.2% of cigarette length; p = .01). These trends were similar in both African Americans and European Americans. The emissions of select toxins per cigarette, as determined by mimicking human smoking behaviors were greater among the male smokers than the female smokers and correlated significantly with delivered smoke volume per cigarette. The geometric means of emissions of nicotine from cigarettes were 1.92 mg/cigarette (95% CI = 1.80-2.05) for women versus 2.20 (95% CI = 2.04-2.37) for men (p = .005). Cigarettes smoked by women yielded 139.5 ng/cigarette of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK; 95% CI = 128.8-151.0), compared with 170.3 ng/cigarette (95% CI = 156.3-185.6) for men (p = .0007); benzo(a)pyrene (BaP) emissions were 18.0 ng/cigarette (95% CI = 17.0-19.0) for women and 20.5 ng/cigarette (95% CI = 18.8-22.3) for men (p = .01). The gender differences with regard to cigarette smoke yields of toxins were more profound in European Americans than in African Americans. On average, African American men's smoking habits produced the highest emissions of select toxins from cigarettes, and European American female smokers had the lowest exposure to carcinogens and toxins. Several studies have suggested that women may be more susceptible than men to the ill effects of carcinogens in tobacco and tobacco smoke, whereas other studies have not found differences in lung cancer risk between men and women. The present study suggests that gender differences in exposure to tobacco smoke cannot account for a higher rate of lung cancer in female smokers compared with male smokers.     

A programmable molecular robot

We have developed a programmable and auton-omous molecular robot whose motion is fueled by DNA hybridization. Instructions determining the path to be followed are programmed into the fuel molecules, allowing precise control of cargo motion on a branched track.     

Interdisciplinary Teaching and Learning in a Semiconductor Processing Course*

An interdisciplinary course in semiconductor processing has been developed and successfully introduced into the chemical, materials, and electrical engineering curricula at San Jose State University. Student teams drawn from a range of engineering and scientific disciplines build microelectronic devices using a five-mask PMOS metal gate process, and perform open-ended experiments to improve this process. The team approach is set in the context of a start-up company culture and professional work environment to give students the opportunity to be actively engaged in constructing their own knowledge base. The wide spectrum of fields and experiences that students bring to the course mirror the highly interdisciplinary nature of microelectronics device processing which requires knowledge of physics, chemistry, and chemical, materials, and electrical engineering. The results from student surveys for the past three years (1995–97) were used to assess the success of this approach and to deduce the most important features for effective teamwork in this context. The elements for good team function and a rich overall learning experience include 1) contributions from and respect for each team member; 2) diverse majors, GPA, and work experiences; and 3) demonstrable leadership from one or two team members.