Temporal patterns in reproduction may explain variationin mating frequencies in the green-veined white butterfly Pieris napi

There is genetic variation in the female mating rate in the green-veined white butterfly (Pieris napi), and females benefit from male ejaculates that contain both sperm and accessory gland substances. Although polyandry corresponds to higher lifetime fecundity than monandry, some females abstain from remating irrespective of the number of available mates. Explaining genetic variation in mating rates requires that monandrous females perform better than polyandrous ones under some conditions. We experimentally explored the reproductive performance of females either with a low or high intrinsic mating rate by allowing them to mate, feed, and lay eggs freely in a laboratory. Individual females followed different life histories: during the early days of reproduction, females with a low mating rate produced more eggs than females with a high mating rate. Hence, refraining from the benefits of multiple mating may be beneficial, if the time for reproduction is limited, or other female traits associated with polyandry are traded off against longevity. Given the day length of 10 h, a model shows that even if polyandrous females enjoy higher lifetime reproductive success, changeable and unpredictable weather will favor monandry if each period of suitable weather lasts, on average, less than 5 days. Thus, a combination of life history cost and unpredictability of fitness may explain the maintenance of monandry in the wild. Our results are also consistent with the observation that frequency of monandry increases with latitude.     

Evolutionarily stable strategies of age-dependent sexual advertisement

In various models of sexual selection mediated by the viability indicator (“good genes”) mechanism, a sexually selected trait will truly reflect male quality if its expression is costly for the male. However, in long-lived species, the expression of a trait often increases with age while the genotype of the male remains unchanged. This fact may obscure the indicator mechanism. Hitherto, game theory models of honesty in sexual advertisement have not taken life-history effects into account, whereas life-history models of reproductive effort have only seldom considered the dependence of mating success on the actions of other individuals. Here, the two approaches are combined, and I examine whether honesty is maintained if males can divide their advertisement effort over their lifetime. The model shows that an increase in the expression of the sexually selected trait over several years is an evolutionarily stable strategy (ESS) under a wide range of situations, so that a correlated preference for old age can emerge through a viability indicator mechanism. Honesty in the strict sense is not preserved: an optimally behaving low-quality male will in some cases advertise more than a high-quality male of equal age, to the extent that the strongest advertisement found in the population can be associated with a low-quality male. Due to life-history trade-offs, however, honesty in an average sense holds true over the lifetime of individuals: “cheater” age classes will remain small enough, that a female will obtain a higher expected mate quality if she trusts in the trait as an indicator of viability. Received: 25 June 1996 / Accepted after revision: 15 April 1997     

Rapid discrimination of plastic packaging materials using MIR spectroscopy coupled with independent components analysis (ICA)

Plastic packaging wastes increased considerably in recent decades, raising a major and serious public concern on political, economical and environmental levels. Dealing with this kind of problems is generally done by landfilling and energy recovery. However, these two methods are becoming more and more expensive, hazardous to the public health and the environment. Therefore, recycling is gaining worldwide consideration as a solution to decrease the growing volume of plastic packaging wastes and simultaneously reduce the consumption of oil required to produce virgin resin. Nevertheless, a major shortage is encountered in recycling which is related to the sorting of plastic wastes. In this paper, a feasibility study was performed in order to test the potential of an innovative approach combining mid infrared (MIR) spectroscopy with independent components analysis (ICA), as a simple and fast approach which could achieve high separation rates. This approach (MIR-ICA) gave 100% discrimination rates in the separation of all studied plastics: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS) and polylactide (PLA). In addition, some more specific discriminations were obtained separating plastic materials belonging to the same polymer family e.g. high density polyethylene (HDPE) from low density polyethylene (LDPE). High discrimination rates were obtained despite the heterogeneity among samples especially differences in colors, thicknesses and surface textures. The reproducibility of the proposed approach was also tested using two spectrometers with considerable differences in their sensitivities. Discrimination rates were not affected proving that the developed approach could be extrapolated to different spectrometers. MIR combined with ICA is a promising tool for plastic waste separation that can help improve performance in this field; however further technological improvements and developments are required before it can be applied at an industrial level given that all tests presented here were performed under laboratory conditions.     

Networking emergency teams in Jerusalem

With the recent upsurge in terrorism, more and more attention is being directed at examining the effectiveness and efficiency of emergency teams. These teams tend to focus on their areas of expertise without necessarily communicating, cooperating or coordinating their operations. Research suggests that improved interpersonal communication and coordination enhances the overall work of each emergency team, and that their combined effort is far in excess of the sum of their individual endeavours. This paper outlines attempts made in Jerusalem to improve the performance of emergency teams and to help the helpers by holding training workshops, setting up a forum of co‐workers and encouraging dialogue among various emergency teams in the city. A planned intervention programme was designed to enable informal networking between team leaders. The programme had an impact on team workers and resulted in a more coordinated and effective service delivery during emergencies.     

Receptor neurones in three heliothine moths responding to floral nd inducible plant volatiles

Summary. Some plant volatiles are produced in response to herbivory of several insect species, including heliothine larvae. In the present study of female heliothine moths, four co-located receptor neurone types were identified, of which three types responded strongest to the inducible compounds E--ocimene, E,E--farnesene and E,E-TMTT, respectively. The fourth type responded strongest to geraniol, which is a common floral volatile. The narrow tuning of each receptor neurone type was demonstrated by responses to a few structurally-related monoterpenes, sesquiterpenes, homo-terpenes and monoterpene alcohols, respectively, out of hundreds of plant constituents tested. The four neurone types showed the same relation of spike amplitudes and ranking of effective compounds in the three heliothine species; the polyphagous Heliothis virescens and Helicoverpa armigera and the oligophagous Helicoverpa assulta. The results indicate the presence of functionally similar types of plant odour-receptor neurones in the three related species, and suggest conservation or reappearance of functionally similar olfactory receptors in related species, independent of the evolution of polyphagy and oligophagy.     

Experience with the use of LCA-modelling (EASEWASTE) in waste management.

Life-cycle assessment (LCA) models are becoming the principal decision support tools of waste management systems. This paper describes our experience with the use of EASEWASTE (Environmental Assessment of Solid Waste Systems and Technologies), a new computerized LCA-based model for integrated waste management. Our findings provide a quantitative understanding of waste management systems and may reveal consistent approaches to improve their environmental performances. EASEWASTE provides a versatile system modelling facility combined with a complete life-cycle impact assessment and in addition to the traditional impact categories addresses toxicity-related categories. New categories dealing with stored ecotoxicity and spoiled groundwater resources have been introduced. EASEWASTE has been applied in several studies, including full-scale assessments of waste management in Danish municipalities. These studies led to numerous modelling issues: the need of combining process-specific and input-specific emissions, the choice of a meaningful time horizon, the way of accounting for biological carbon emissions, the problem of stored ecotoxicity and aspects of crediting the waste management system with the savings inherent in avoided production of energy and materials. Interpretation of results showed that waste management systems can be designed in an environmentally sustainable manner where energy recovery processes lead to substantial avoidance of emissions and savings of resources.     

Real-world vehicle emissions as measured by in situ analysis of exhaust plumes

Environmental Science and Pollution Research - We conducted a 60-day roadside measurement campaign on a busy street in Münster, Germany, during summer 2016. We used gas and particle...     

Regional Monitoring of Ambient Air Carbon Monoxide in Fairbanks,Alaska

A method employing the timed fill of Mylar bags was used to obtain average carbon monoxide concentration values for ten locations in the Fairbanks, Alaska, area. The method is shown to be accurate, reliable, and inexpensive. The correlation coefficient between the bag sampling method and a continuous carbon monoxide analyzer was 0.945; correlation of carbon monoxide data from several locations to a reference in downtown Fairbanks showed a general decrease with distance from the reference analyzer. Analysis of data from Fairbanks shows that carbon monoxide concentrations during the winter months may have to be reduced 50-75% to achieve the State and National Ambient Air Quality Standards; the high levels of carbon monoxide are the result of emissions from automobile traffic during periods of severe inversion in the Fairbanks basin.     

A Simple Method of Calculating Dispersion from Urban Area Sources

A simple but physically realistic model is shown to be adequate for estimating pollutant concentrations due to area sources in cities. In this model, the surface concentration is directly proportional to the local area source strength and inversely proportional to the wind speed. The model performs nearly as well as much more complex models that require the use of digital computers.