The energetic costs of stereotyped behavior in the paper wasp, Polistes dominulus

Polistes wasps engage in many behavioral interactions. Although there has been debate over the meaning of these interactions, these stereotypical behaviors can be used to determine a colony’s linear dominance hierarchy. Due to the implicit relationship between behavioral and reproductive dominance, behavioral interactions are commonly used to distinguish the reproductively dominant alpha foundress from the beta foundress. It has been suggested that in order to maintain reproductive control, the alpha foundress is forced to remain at a physiologically constrained activity limit. This, in turn, may allow aggressive interactions to be used as determinants influencing reproductive partitioning between cooperating individuals. Energetic costs can place important limitations on behavior, but the energetic cost of the interactions has not previously been measured. To address this, we measured the CO₂ production of 19 non-nestmate pairs displaying interactive and noninteractive behavior. The rate of energy used during interaction behavior was positively associated with published rankings of aggression. However, our results indicate that interactions are not very energetically costly in Polistes, particularly when compared to the likely cost of foraging. These data suggest that maintaining reproductive dominance is not very energetically expensive for the dominant and that the dominant foundress expends energy at a lower rate than the subordinate foundress. Electronic Supplementary Material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effectiveness and driver acceptance of the Honda belt reminder system

OBJECTIVE: Prior research suggests that vehicle-based seat belt reminder systems can produce moderate increases in belt use rates. However, these findings were based on a limited set of Ford vehicles in one geographic location. As more vehicles with reminder systems enter the market, it is important to determine their effectiveness as well as acceptance by consumers. The present study investigated the effectiveness of Honda's belt reminder system. METHODS: Driver belt use was observed unobtrusively as drivers brought their Honda vehicles to dealerships for service. Drivers also were asked to complete a mail-in survey designed to elicit their experience with the system. RESULTS: Belt use was significantly higher among drivers of vehicles with belt reminders compared with drivers of vehicles without reminders (90 vs. 84 percent). Use rates in vehicles with reminders were higher among both male and female drivers and in all vehicle types observed. Drivers of the Honda vehicles with belt reminders viewed the system very favorably, and nearly 90 percent said they would want one in their next vehicle. The reminder was perceived to be most effective by part-time belt users; 81 percent of part-time users said they now use belts more often, compared with 32 percent of respondents who said they always use belts and 18 percent who use belts occasionally. CONCLUSION: Belt reminders in Honda as well as Ford vehicles are increasing. Although the increase is moderate (5.6 percentage points), on a national level it could have prevented at least 736 driver deaths in 2004.     

The effectiveness of electronic stability control in reducing real-world crashes: a literature review

OBJECTIVE: Electronic stability control (ESC) is designed to help drivers maintain heading control of their vehicles in high-speed or sudden maneuvers and on slippery roads. The wider proliferation of ESC across the vehicle fleet has allowed evaluation of its effects in real-world crashes in many countries, including Japan, Germany, Sweden, France, Great Britain, and the United States. This article provides a summary of the findings. METHODS: Studies that examined the real-world effectiveness of ESC were reviewed. Crash effects have been examined for different roadways, using differing analytic methods, different crash severities, and different make/model vehicles including both cars and SUVs. The review discusses the methodological differences and examines the findings according to vehicle type, crash type and severity, and road conditions. RESULTS: The overwhelming majority of studies find that ESC is highly effective in reducing single-vehicle crashes in cars and SUVs. Fatal single-vehicle crashes involving cars are reduced by about 30-50% and SUVs by 50-70%. Fatal rollover crashes are estimated to be about 70-90% lower with ESC regardless of vehicle type. A number of studies find improved effectiveness in reducing crashes when road conditions are slippery. There is little or no effect of ESC in all multi-vehicle crashes; however, there is a 17-38% reduction in more serious, fatal multi-vehicle crashes. CONCLUSIONS: Given the extraordinary benefits of ESC in preventing crashes, especially those with more serious outcomes, the implementation of ESC should be accelerated to cover the full range of passenger vehicles in both developed and developing markets.     

Hardcore drinking drivers and other contributors to the alcohol-impaired driving problem: need for a comprehensive approach

OBJECTIVE: Understanding the hardcore drinking driver concept in the context of the alcohol-impaired driving problem. METHOD: Review of the relevant literature. RESULTS: As progress against alcohol-impaired driving slowed in the early 1990s, public and political attention turned to "hardcore" drinking drivers, and they have been a priority for the past 15 years. Though intuitive, the hardcore concept has been difficult to conceptualize. Its definition of hard-to-change chronic heavy drinking drivers focuses on a group that is not easily identifiable and ignores many who account for a large portion of alcohol-impaired driving crashes. These include drivers who drink heavily on occasion and drivers who drink at more moderate levels that elevate crash risk. Emphasis on the hardcore has focused attention on the small proportion of drinking drivers who have been detected and arrested, whereas the vast majority of drinking drivers go undetected. Some countermeasures aimed at the hardcore group have been effective in reducing recidivism, but attention and resources also need to be given to general deterrent initiatives (e.g., 0.08 g/dL, sobriety checkpoints, administrative license suspension). There has been no reduction in the overall alcohol-impaired driving problem since the mid-1990s. CONCLUSION: Reductions in the alcohol-impaired driving problem require that attention be focused on all relevant target groups. Some benefits could accrue by recognizing that countermeasures developed for hardcore drinking drivers, such as alcohol ignition interlocks and vehicle or plate impoundment, might also be effective with more numerous first-time offenders. However, such strategies are likely to be most effective against recidivism (specific deterrence). Greater gains could be achieved through general deterrent efforts (increasing the real and perceived risk of arrest and punishment to all drinking drivers), along with application of public health measures designed to reduce overall consumption. Additional ways need to be found to separate drinking and driving, either through cultural changes in drinking and/or driving behavior or, in the future, with the use of technology that can make vehicles inoperable by drivers with illegal blood alcohol concentrations.     

A gravid lizard from the Cretaceous of China and the early history of squamate viviparity

Although viviparity is most often associated with mammals, roughly one fifth of extant squamate reptiles give birth to live young. Phylogenetic analyses indicate that the trait evolved more than 100 times within Squamata, a frequency greater than that of all other vertebrate clades combined. However, there is debate as to the antiquity of the trait and, until now, the only direct fossil evidence of squamate viviparity was in Late Cretaceous mosasauroids, specialised marine lizards without modern equivalents. Here, we document viviparity in a specimen of a more generalised lizard, Yabeinosaurus, from the Early Cretaceous of China. The gravid female contains more than 15 young at a level of skeletal development corresponding to that of late embryos of living viviparous lizards. This specimen documents the first occurrence of viviparity in a fossil reptile that was largely terrestrial in life, and extends the temporal distribution of the trait in squamates by at least 30 Ma. As Yabeinosaurus occupies a relatively basal position within crown-group squamates, it suggests that the anatomical and physiological preconditions for viviparity arose early within Squamata.     

A capabilities approach to the prioritization of critical infrastructure

As a consequence of the U.S. effort to increase infrastructure security and resilience, the Department of Homeland Security (DHS) and other U.S. federal agencies have identified 16 critical infrastructure sectors that are considered vital to the nation’s well-being in terms of economic security, public health, and safety. However, there remains no articulated set of values that justify this particular list of infrastructure systems or how decision-makers might prioritize investments towards one critical sector over another during a crisis. To offer a more integrated and holistic approach to critical infrastructure resilience, this research employs the capabilities approach to human development, which offers an alternative view of critical infrastructure that focuses on the services that infrastructure provides rather than its physical condition or vulnerability to threats. This service-based perspective of infrastructure emphasizes the role of infrastructure in enabling and supporting central human capabilities that build adaptive capacity and improve human well-being. We argue that the most critical infrastructure systems are those that are essential for providing and/or supporting central human capabilities. This paper examines the DHS designation of criticality from a capabilities perspective and argues for a capabilities basis for making distinctions between those systems that should be considered most critical and those that might be temporarily sacrificed. A key implication of this work is that an across sector approach is required to reorganize existing critical infrastructure efforts around the most valuable infrastructure end-services.     

Flow,Organic, and Inorganic Sediment Yields from a Channelized Watershed in the South Carolina Lower Coastal Plain

Many small streams in coastal watersheds in the southeastern United States are modified for agricultural, residential, and commercial development. In the South Carolina Lower Coastal Plain, low‐relief topography and a shallow water table make stream channelization ubiquitous. To quantify the impacts of urbanization and stream channelization, we measured flow and sediment from an urbanizing watershed and a small forested watershed. Flow and sediment export rates were used to infer specific yields from forested and nonforested regions of the urbanizing watershed. Study objectives were to: (1) quantify the range of runoff‐to‐rainfall ratios; (2) quantify the range of specific sediment yields; (3) characterize the quantity and quality of particulate matter exported; and (4) estimate sediment yield attributable to agriculture, development, and channelization activities in the urbanizing watershed. Our results showed that the urban watershed exported over five times more sediment per unit area compared with the forested watershed. Sediment concentration was related to flow flashiness in the urban watershed and to flow magnitude in the forested watershed. Sediments from the forested watershed were dominated by organic matter, whereas mineral matter dominated sediment from the urban stream. Our results indicated that a significant shift in sediment quality and quantity are likely to occur as forested watersheds are transformed by urbanization in coastal South Carolina.     

Signaling effort does not predict aggressiveness in male spring field crickets

The relationship between signaling and aggression is still unclear despite several decades of research. However, there is a growing interest in studying signals that predict aggressive behavior or fighting ability. The goals of our study were threefold: we investigated the relationship between signaling effort and aggression, the relationship between body condition and aggression, and the effect of fighting experience on subsequent signaling behavior in wild-caught and laboratory-reared male spring field crickets (Gryllus veletis). We found that aggressive behavior was not related to signaling effort, body size, or body condition. For contest winners, wild-captured males were more aggressive than laboratory-reared males. Signaling effort was highly repeatable within individuals, but aggressive behavior had low repeatability. We found no evidence for a winner or loser effect on signaling; there was no change in signaling effort when we compared contest winners and losers before and after they participated in aggressive contests. Long-distance acoustic signaling and aggressive behavior appear to be independent of one another in spring field crickets, perhaps serving different functions in female attraction and male–male competition, respectively.     

Sustainable shrimp fishery management recommendations for a coastal lagoon in Baja California Sur,Mexico

The Baja California Peninsula is considered México's most productive in terms of commercial fisheries. Very few quantitative assessments of the economic importance of this region exist, especially considering artisanal fisheries and their relationships with ecological data. Datasets from government records on shrimp capture in Magdalena Bay, an arid coastal lagoon of Baja California Sur were collected, analysed and correlated with ecological data. Over the 10-year period analysed, fisheries from Magdalena Bay made up 27.5% of the shrimp capture of the state, contributing over US$15.5 million to the economy of the country. The impressive value of this resource warrants considerable attention in the design of land-use plans for the future of the region. Analysis of ecological and economical data on shrimp fishery activities in the Magdalena Bay region enables us to propose recommendations to enhance the sustainable development of the local inhabitants. A thorough assessment of the potential value of alternative economic activities should be conducted to determine their potential to provide similar productive use of the natural resources of the region as the shrimp fishery. Also, from a more specific management viewpoint, harvest rates of small shrimp in the channels should be reduced.     

Evidence for covalently bonded chlorine–fullerene formed by ozonation and chlorination at room temperature

This article reports for the first time that fullerene (nC₆₀) can form chlorinated disinfection by-products in aqueous systems at ambient temperature. The ability of nC₆₀ to form colloidal suspensions in aqueous media increases the chance that these particles will migrate in the environment and then in drinking water supply systems. Since nC₆₀ is not completely removed by conventional water treatment, any residual nC₆₀ is likely to be oxidized during disinfection process. While the ozonation of nC₆₀ has been studied, little is known about the reaction between nC₆₀ and chlorine. To address this issue, we subjected aqueous nC₆₀ suspensions to chlorination and sequential ozonation/chlorination at ozone dosages of 4.5, 10, 15 and 24 mg O₃/mg nC₆₀. The morphology and physicochemical properties of oxidized nC₆₀ aggregates were evaluated by scanning electron microscopy, transmission electron microscopy, UV–visible absorption spectroscopy and X-ray photoelectron spectroscopy (XPS). We found that while the particles in the as-prepared nC₆₀ were predominantly spheres, the ozonation of nC₆₀ resulted in the formation of irregularly shaped aggregates. The concentration of atomic carbon found by XPS in the nC₆₀ samples decreased from 92 % for the as-prepared nC₆₀ to 50 % for the aggregates ozonated at 24 mg O₃/mg nC₆₀ and then chlorinated at 68 mg Cl₂/L and allowed to react for 100 min. The presence of Cl atoms covalently bonded to C atoms was confirmed by XPS peaks corresponding to a binding energy (E _b) of 200.1–202.4 eV. This demonstrates the need to better assess and monitor the formation of potentially toxic chlorinated disinfection by-products from carbon nanomaterials during water treatment.