Changes in the spatial distribution of spawning activity by north-east Atlantic mackerel in warming seas: 1977–2010

Migratory species with a broad geographic range, such as north-east Atlantic mackerel, may be amongst the fauna most able to respond to warming seas, typically with a poleward shift in range. Habitat heterogeneity could, however, produce more complex patterns than a simple polewards translation in distribution. We tested for changes in the central location and spatial spread of mackerel spawning over a 33-year period. Spatial statistics [centre of gravity (CoG) of egg production, spatial variance, and degree of anisotropy] were used to summarise interannual changes in the spawning locations of the western spawning stock of north-east Atlantic mackerel (NEA-WSC) using data from the ICES triennial egg survey. A northwards shift in CoG of egg production estimates was observed, related to both an expansion in the distribution in survey effort and warming waters of the north-east Atlantic. Sea surface temperature (SST) had a significant positive association with the observed northward movement of NEA-WSC mackerel, equivalent to a displacement of 37.7 km °C^?1 (based on spring mean SST for the region). The spatial distribution of spawning around the CoG also changed significantly with SST, with a less elongated spatial spread in warm years. An increase in the proportion of spawning over the Porcupine Bank demonstrated how habitat interacts with positional shifts to affect how north-east Atlantic mackerel are distributed around the centre of their spawning range.     

Building regional priorities in forests for development and adaptation to climate change in the Congo Basin

Indentifying common priorities in shared natural resource systems constitutes an important platform for implementing adaptation and a major step in sharing a common responsibility in addressing climate change. Predominated by discourses on REDD + (Reduced Emissions from Deforestation and Forest Degradation and conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries) with little emphasis on adaptation there is a risk of lack of policy measures in addressing climate change in the Congo Basin. Forest products and ecosystem services provide security portfolios for the predominantly rural communities, and play major roles in national development programmes in both revenue and employment opportunities. Thus, raising the profile of forests in the policy arena especially in the twin roles of addressing climate change in mitigation and adaptation and achieving resilient development is crucial. Within the framework of the Congo Basin Forests and Climate Change Adaptation project (COFCCA) project, science policy dialogue was conducted to identify and prioritize forest based sectors vulnerable to climate change but important to household livelihoods and national development. The goal of the prioritization process was for the development of intervention in forest as measures for climate change adaptation in Central Africa. Participants constituted a wide range of stakeholders (government, Non Governmental Organizations, research institutions, universities, community leaders, private sectors etc.) as representatives from three countries directly involved in the project: Cameroon, Central African Republic and Democratic Republic of Congo. Building on national priorities, four forest related sectors were identified as common priorities at the regional level for focus on climate change adaptation. These sectors included: (1) energy with emphasis on fuel wood and Charcoal; (2) Water principally quality, quantity, accessibility, etc.; (3) Food with emphasis on Non Timber Forest Products, and (4) Health linked to healthcare products (medicinal plants). Using these prioritized sectors, the project focused on addressing the impacts of climate change on local communities and the development of adaptation strategies in the three pilot countries of the Congo Basin region. The four sectors constitute the key for development in the region and equally considered as priority sectors in the poverty reduction papers. Focused research on these sectors can help to inject the role of forests in national and local development and their potentials contributions to climate change adaptation in national and public discourses. Mainstreaming forest for climate change adaptation into national development planning is the key to improve policy coherence and effectiveness in forest management in the region.     

Modeling and interpretation of fiber orientation-based failure mechanisms in machining of carbon fiber-reinforced polymer composites

The development and implementation of a microstructure-based finite element model for the machining of carbon fiber-reinforced polymer composites is presented. A new approach to interfacial modeling is introduced where the material interface is modeled using continuum elements, allowing failure to take place in either tension or compression. The model is capable of describing the fiber failure mode occurring throughout the chip formation process. Characteristic fiber length in the chips, and machining forces for microstructures with fibers orientated at 0°, 45°, 90°, and 135° are examined. For model validation purposes, the model-based machining performance predictions are compared to the machining responses from a set of orthogonal machining experiments. A parametric study is presented that identifies a robust tool geometry, which minimizes the effects of fiber orientation and size on the machining forces.     

The predictive validity of safety climate

PROBLEM: Safety professionals have increasingly turned their attention to social science for insight into the causation of industrial accidents. One social construct, safety climate, has been examined by several researchers [Cooper, M. D., & Phillips, R. A. (2004). Exploratory analysis of the safety climate and safety behavior relationship. Journal of Safety Research, 35(5), 497-512; Gillen, M., Baltz, D., Gassel, M., Kirsch, L., & Vacarro, D. (2002). Perceived safety climate, job Demands, and coworker support among union and nonunion injured construction workers. Journal of Safety Research, 33(1), 33-51; Neal, A., & Griffin, M. A. (2002). Safety climate and safety behaviour. Australian Journal of Management, 27, 66-76; Zohar, D. (2000). A group-level model of safety climate: Testing the effect of group climate on microaccidents in manufacturing jobs. Journal of Applied Psychology, 85(4), 587-596; Zohar, D., & Luria, G. (2005). A multilevel model of safety climate: Cross-level relationships between organization and group-level climates. Journal of Applied Psychology, 90(4), 616-628] who have documented its importance as a factor explaining the variation of safety-related outcomes (e.g., behavior, accidents). Researchers have developed instruments for measuring safety climate and have established some degree of psychometric reliability and validity. The problem, however, is that predictive validity has not been firmly established, which reduces the credibility of safety climate as a meaningful social construct. The research described in this article addresses this problem and provides additional support for safety climate as a viable construct and as a predictive indicator of safety-related outcomes. METHODS: This study used 292 employees at three locations of a heavy manufacturing organization to complete the 16 item Zohar Safety Climate Questionnaire (ZSCQ) [Zohar, D., & Luria, G. (2005). A multilevel model of safety climate: Cross-level relationships between organization and group-level climates. Journal of Applied Psychology, 90(4), 616-628]. In addition, safety behavior and accident experience data were collected for 5 months following the survey and were statistically analyzed (structural equation modeling, confirmatory factor analysis, exploratory factor analysis, etc.) to identify correlations, associations, internal consistency, and factorial structures. RESULTS: Results revealed that the ZSCQ: (a) was psychometrically reliable and valid, (b) served as an effective predictor of safety-related outcomes (behavior and accident experience), and (c) could be trimmed to an 11 item survey with little loss of explanatory power. IMPACT ON INDUSTRY: Practitioners and researchers can use the ZSCQ with reasonable certainty of the questionnaire's reliability and validity. This provides a solid foundation for the development of meaningful organizational interventions and/or continued research into social factors affecting industrial accident experience.     

Sexual selection on receptor organ traits: younger females attract males with longer antennae

Sexual selection theory predicts that female choice may favour the evolution of elaborate male signals. Darwin also suggested that sexual selection can favour elaborate receiver structures in order to better detect sexual signals, an idea that has been largely ignored. We evaluated this unorthodox perspective by documenting the antennal lengths of male Uraba lugens Walker (Lepidoptera: Nolidae) moths that were attracted to experimentally manipulated emissions of female sex pheromone. Either one or two females were placed in field traps for the duration of their adult lives in order to create differences in the quantity of pheromone emissions from the traps. The mean antennal length of males attracted to field traps baited with a single female was longer than that of males attracted to traps baited with two females, a pattern consistent with Darwin’s prediction assuming the latter emits higher pheromone concentrations. Furthermore, younger females attracted males with longer antennae, which may reflect age-specific changes in pheromone emission. These field experiments provide the first direct evidence of an unappreciated role for sexual selection in the evolution of sexual dimorphism in moth antennae and raise the intriguing possibility that females select males with longer antennae through strategic emission of pheromones.     

Aldehyde and Monocyclic Aromatic Hydrocarbon Mixing Ratios at an Urban Site in Las Vegas,Nevada

ABSTRACT

Linhong Jing completed a master's degree in chemistry at UNLV and is currently enrolled in the Ph.D. program at Purdue University. Her address is Department of Chemistry, Purdue University, West Lafayette, IN 47907. Dr. Spencer Steinberg is an associate professor of chemistry at UNLV. His address is UNLV Department of Chemistry, P.O. Box 454003, Las Vegas, NV 89154-4003. Dr. Brian Johnson is an associate professor of chemistry at UNLV. His address is UNLV Department of Chemistry, P.O. Box 454003, Las Vegas, NV 89154-4003.

Oxidation of benzene, toluene, ethylbenzene, and xylenes (BTEX) in air, of significance due to, for example, the potential for O₃ formation, is believed to be initiated by OH attack on the ring (addition) or on the alkyl side chain (H abstraction). A series of ring-breaking reactions follows, with major products predicted to be a-dicarbonyls, simple aldehydes, and organic acids. To test this prediction, ambient air mixing ratios of aldehydes (formaldehyde, ac-etaldehyde, benzaldehyde, glyoxal, and pyruvaldehyde), along with some supporting BTEX data, were measured at an urban site in Las Vegas, NV. Samples were collected on sorbents and determined by chromatographic methods; mixing ratios were compared to ambient levels of CO, O₃, and NO_x. A meteorological analysis (temperature, wind speed, and wind direction) was also included. Statistically significant relationships were noted among the BTEX hydrocarbons (HCs) and among the photochemi-cally derived species (e.g., O₃, NO₂, and some of the aldehydes), although there was seasonal variation. The observations are consistent with a common primary source (i.e., vehicular exhaust or fuel evaporation) for the BTEX compounds and a common secondary source (e.g., OH attack) for glyoxal and pyruvaldehyde.     

Nitrogen critical loads and management alternatives for N-impacted ecosystems in California

Empirical critical loads for N deposition effects and maps showing areas projected to be in exceedance of the critical load (CL) are given for seven major vegetation types in California. Thirty-five percent of the land area for these vegetation types (99,639 km²) is estimated to be in excess of the N CL. Low CL values (3–8 kg N ha^?1 yr^?1) were determined for mixed conifer forests, chaparral and oak woodlands due to highly N-sensitive biota (lichens) and N-poor or low biomass vegetation in the case of coastal sage scrub (CSS), annual grassland, and desert scrub vegetation. At these N deposition critical loads the latter three ecosystem types are at risk of major vegetation type change because N enrichment favors invasion by exotic annual grasses. Fifty-four and forty-four percent of the area for CSS and grasslands are in exceedance of the CL for invasive grasses, while 53 and 41% of the chaparral and oak woodland areas are in exceedance of the CL for impacts on epiphytic lichen communities. Approximately 30% of the desert (based on invasive grasses and increased fire risk) and mixed conifer forest (based on lichen community changes) areas are in exceedance of the CL. These ecosystems are generally located further from emissions sources than many grasslands or CSS areas. By comparison, only 3–15% of the forested and chaparral land areas are estimated to be in exceedance of the NO₃^? leaching CL. The CL for incipient N saturation in mixed conifer forest catchments was 17 kg N ha^?1 yr^?1. In 10% of the CL exceedance areas for all seven vegetation types combined, the CL is exceeded by at least 10 kg N ha^?1 yr^?1, and in 27% of the exceedance areas the CL is exceeded by at least 5 kg N ha^?1 yr^?1. Management strategies for mitigating the effects of excess N are based on reducing N emissions and reducing site N capital through approaches such as biomass removal and prescribed fire or control of invasive grasses by mowing, selective herbicides, weeding or domestic animal grazing. Ultimately, decreases in N deposition are needed for long-term ecosystem protection and sustainability, and this is the only strategy that will protect epiphytic lichen communities.     

Natural emissions for regional modeling of background ozone and particulate matter and impacts on emissions control strategies

Natural emissions adopted in current regional air quality modeling are updated to better describe natural background ozone and PM concentrations for North America. The revised natural emissions include organosulfur from the ocean, NO from lightning, sea salt, biogenic secondary organic aerosol (SOA) precursors, and pre-industrial levels of background methane. The model algorithm for SOA formation was also revised. Natural background ozone concentrations increase by up to 4 ppb in annual average over the southeastern US and Gulf of Mexico due to added NO from lightning while the revised biogenic emissions produced less ozone in the central and western US. Natural PM_2.5 concentrations generally increased with the revised natural emissions. Future year (2018) simulations were conducted for several anthropogenic emission reduction scenarios to assess the impact of the revised natural emissions on anthropogenic emission control strategies. Overall, the revised natural emissions did not significantly alter the ozone responses to the emissions reductions in 2018. With revised natural emissions, ozone concentrations were slightly less sensitive to reducing NOx in the southeastern US than with the current natural emissions due to higher NO from lightning. The revised natural emissions have little impact on modeled PM_2.5 responses to anthropogenic emission reductions. However, there are substantial uncertainties in current representations of natural sources in air quality models and we recommend that further study is needed to refine these representations.     

Effects of a complex archipelago on genetic subdivision of the intertidal limpet Siphonaria kurracheensis

Allozyme variation in the intertidal limpet Siphonaria kurracheensis was examined in 11 populations from the Houtman Abrolhos Islands, Western Australia, and four from the adjacent mainland, to test if the effects of these islands on genetic subdivision should include species with high dispersal. Consistent with extensive planktonic dispersal, genetic subdivision was low, with an average standardized variance in allelic frequencies (F_ST) of 0.010 over 400 km along the mainland, and 0.009 over 70 km in the Abrolhos Islands. Nevertheless, subdivision was statistically significant at the smallest scale examined (about 10 km), showing a pattern of local heterogeneity and large-scale homogeneity, which is common in planktonic dispersers. Among the island populations, heterozygosity was positively correlated with a multivariate index of exposure. The level of heterozygosity at the most exposed island sites is equivalent to that at the (also exposed) mainland sites, whereas it is lower in the most sheltered island sites. Although this indicates that some island populations are less well connected to the major pool of larvae, the overall effect of the archipelago on genetic subdivision is no greater than occurs on the mainland coast. This is contrary to findings in previously studied species with less potential for dispersal, suggesting that the local impediments to dispersal are selective in their effects, and are unlikely to be broadly important for genetic divergence in widely dispersing species.