Coupled effects of solution chemistry and hydrodynamics on the mobility and transport of quantum dot nanomaterials in the vadose zone

To investigate the coupled effects of solution chemistry and hydrodynamics on the mobility of quantum dot (QD) nanoparticles in the vadose zone, laboratory scale transport experiments involving single and/or sequential infiltrations of QDs in unsaturated and saturated porous media, and computations of total interaction and capillary potential energies were performed. As ionic strength increased, QD retention in the unsaturated porous media increased; however, this retention was significantly suppressed in the presence of a non-ionic surfactant in the infiltration suspensions as indicated by surfactant enhanced transport of QDs. In the vadose zone, the non-ionic surfactant limited the formation of QD aggregates, enhanced QD mobility and transport, and lowered the solution surface tension, which resulted in a decrease in capillary forces that not only led to a reduction in the removal of QDs, but also impacted the vadose zone flow processes. When chemical transport conditions were favorable (ionic strength of 5 × 10(-4)M and 5 × 10(-3)M, or ionic strengths of 5 × 10(-2)M and 0.5M with surfactant), the dominating phenomena controlling the mobility and transport of QDs in the vadose zone were meso-scale processes, where infiltration by preferential flow results in the rapid transport of QDs. When chemical transport conditions were unfavorable (ionic strength of 5 × 10(-2)M and 0.5M) the dominating phenomena controlling the mobility and transport of QDs in the vadose zone were pore-scale processes governed by gas-water interfaces (GWI) that impact the mobility of QDs. The addition of surfactant enhanced the transport of QDs both in favorable and unfavorable chemical transport conditions. The mobility and retention of QDs was controlled by interaction and capillary forces, with the latter being the most influential. GWI were found to be the dominant mechanism and site for QD removal compared with solid-water interfaces (SWI) and pore straining. Additionally, ripening phenomena were demonstrated to enhance QDs removal or retention in porous media and to be attenuated by the presence of surfactant.     

The significance of a small, level-3 'semi evacuation' hospital in a terrorist attack in a nearby town

Terrorist attacks can occur in remote areas causing mass-casualty incidents MCIs far away from level-1 trauma centres. This study draws lessons from an MCI pertaining to the management of primary and secondary evacuation and the operational mode practiced. Data was collected from formal debriefings during and after the event, and the medical response, interactions and main outcomes analysed using Disastrous Incidents Systematic Analysis through Components, Interactions and Results (DISAST-CIR) methodology. A total of 112 people were evacuated from the scene-66 to the nearby level 3 Laniado hospital, including the eight critically and severely injured patients. Laniado hospital was instructed to act as an evacuation hospital but the flow of patients ended rapidly and it was decided to admit moderately injured victims. We introduce a novel concept of a 'semi-evacuation hospital'. This mode of operation should be selected for small-scale events in which the evacuation hospital has hospitalization capacity and is not geographically isolated. We suggest that level-3 hospitals in remote areas should be prepared and drilled to work in semi-evacuation mode during MCIs.     

Prostaglandin F2α facilitates female mating behavior based on male performance

Hormones play an important role in the regulation of reproductive behavior. Here, we examined the effects of the fatty acid derivative prostaglandin F2α (PGF2) on female sexual behavior as well as the interaction between PGF2-induced mating behavior with male courtship display in the lek-breeding African cichlid fish, Astatotilapia burtoni. In a two-way choice paradigm, we found that nonreproductive females preferred to associate with smaller, less aggressive males over larger, more aggressive males. However, PGF2-treated females dramatically reversed their preference to larger males. In a second experiment, PGF2 treatment dramatically increased sexual behavior in nonreproductive females as measured by time spent in the bower of the stimulus male, even when the female and the stimulus male were separated by a transparent divider. This effect was even more pronounced when the stimulus males were exposed to the putative female pheromone 17α,20β-progesterone (17α,20β-P). Under full-contact conditions, only PGF2-treated females visited a stimulus male’s bower, where they even displayed circling behavior usually only seen during spawning. Interestingly, male performance prior to PGF2 treatment predicted female sexual response. Our study demonstrates the importance of PGF2 in the control of female reproductive behavior in interaction with male performance.     

可持续建筑业的社会责任:国际劳工组织的观点

本文调查了可持续建筑业的社会形势,特别是发展中国家的可持续建筑业,一个有社会责任感的建筑产业,就是一个在保护劳工免受负面影响的同时努力加强正面影响作用的产业,这要求遵守劳动标准,正如"国际劳工组织(ILO)协定"和国家立法所表达的那样,志愿行动已经做出了积极的贡献,但是严格的计划将要求每一个人依照相同的游戏规则,要做到如此,全体利益相关者确定的统一行动是十分必要的,一个新的"社会责任感建设投资"行动,由国际劳工组织发起,它将把政府代表,雇主,工人和其他主要建筑利益相关者聚在一起,其目的是要制定战略和行动计划,以加强建筑作业中关键劳动标准的贯彻,以及推动建筑部门的生产性就业.     

The fatality consequences of the 65 mph speed limits, 1989

This study examined whether the number of fatalities on rural interstates in 1989 was higher than would be expected based on experience during 1982–1986 and experience on all other roads. Among the 40 states that increased the speed limit to 65 mph on rural interstates, the number of fatalities was 29% higher than expected. Among the eight states retaining a 55 mph maximum speed limit on rural interstates, the observed number of fatalities was 12% lower than expected, although this reduction was not statistically significant. After adjusting the fatality risk on rural interstates for differences in vehicle miles traveled on those roads and for higher passenger vehicle occupancy rates attributable to possible increases in vacation travel, the increased fatality risk was 19%. These data suggest that the majority of the estimated increase in fatalities on rural interstates in 1989 (almost 400 of the approximately 600 extra deaths) can be attributed to the higher speeds resulting from the higher speed limits. Changes in mileage account for the remaining 200 extra deaths.     

Characteristics of vehicle-animal crashes in which vehicle occupants are killed

During the past 10 years almost 1,500 people have been killed in motor vehicle collisions with animals. Police reports on 147 fatal vehicle-animal crashes during 2000-2002 were obtained from nine states. The goal was to determine common crash types, types of animals involved, and steps that could be taken to reduce the crashes and injuries. Seventy-seven percent of the struck animals were deer, but six other types of animals were involved including small ones such as dogs. Eighty percent of the crashes were single-vehicle events. In most of these cases a motorcycle struck an animal and the rider came off the vehicle, or a passenger vehicle struck an animal and then ran off the road; in a few cases the animal went through the windshield. Multiple-vehicle crashes included vehicles striking deer that went through the windshields of oncoming vehicles, vehicles striking animals and then colliding with other vehicles, and vehicles striking animals that subsequently were struck by other vehicles. Crashes occurred primarily in rural areas, on roads with 55 mph or higher speed limits, during evening or nighttime hours, and in darkness. Greater application of deer-vehicle collision countermeasures known to be effective is needed, but it is noteworthy that a majority of fatalities occurred from subsequent collisions with other vehicles or objects, not from animal contacts. Sixty-five percent of motorcyclists killed were not wearing helmets, and 60% of vehicle occupants killed were unbelted; many of these fatalities would not have occurred with proper protection.     

Sixteen-year-old drivers in fatal crashes, United States, 2003

OBJECTIVE: Key features of graduated licensing were introduced in 46 states and the District of Columbia between 1993 and 2003. State evaluations consistently have reported positive overall effects and positive effects of nighttime and passenger restrictions. Sixteen year-olds are the main target of graduated licensing, and the present study investigated changes in their fatal crash involvement and crash characteristics that have taken place nationally during 1993-2003. By looking at 16 year-olds nationally, the study does not constitute a direct test of the effect of graduated licensing laws per se. METHODS: Data on fatal crashes were obtained from the Fatality Analysis Reporting System. Sixteen year-olds were compared with older drivers. RESULTS: During these years, the extent to which 16-year-old drivers were in fatal crashes decreased substantially compared with older age groups. The drop in the per capita crash rate for 16 year-olds was 26%. The major change was a reduction in crashes involving transporting young passengers, especially in jurisdictions with restrictions that target these crashes. There was no change in the proportion of fatal late-night crashes even in states restricting this activity. CONCLUSIONS: There has been some progress nationally in reducing the crash problem for 16 year-olds, but this still is a big problem. To achieve further progress, the gaps and weaknesses in present graduated licensing laws will need to be addressed.     

Interspecific acoustic interactions of the neotropical treefrog Hyla ebraccata

Summary Hyla ebraccata, H. microcephala and H. phlebodes commonly occur together in Panama. The three species have calls exhibiting broad frequency overlap and call during the same season and time of day from similar microhabitats, frequently in close proximity. The vocal repertoires of the three species are structurally and functionally similar. All employ multi-part advertisement and aggressive calls which consist of a primary note followed by a variable number of clicks. H. ebraccata males often responded to heterospecific calls with multi-note synchronized responses, and calls with primary notes greater than 150–200 ms were most effective in eliciting synchrony. Playback experiments with synthetic 1-note advertisement calls of different durations and both synthetic 1-note advertisement calls and 200 ms tones of different frequencies demonstrated that H. ebraccata males will synchronize with stimuli which are similar in frequency and duration to conspecific calls. Data from a two-choice experiment with female H. ebraccata demonstrate that calls of individual H. microcephala can reduce the attractiveness of a H. ebraccata male's calls if primary notes overlap. By synchronizing response calls to those of H. microcephala, a H. ebraccata may reduce the chances that his calls are rendered less attractive to potential mates.Aggressive calls of these species are graded and are characterized by higher pulse repetition rates and often longer durations than advertisement calls. H. ebraccata males respond to aggressive calls of H. microcephala and H. phlebodes as they do to their own calls. Heterospecific aggressive interactions probably occur because the species interfere acoustically. Our results demonstrate that H. ebraccata males behave in ways which enhance their ability to communicate in a noisy assemblage of conspecific and heterospecific males.