Interactions of Physical, Chemical, and Biological Weather Calling for an Integrated Approach to Assessment, Forecasting, and Communication of Air Quality

This article reviews interactions and health impacts of physical, chemical, and biological weather. Interactions and synergistic effects between the three types of weather call for integrated assessment, forecasting, and communication of air quality. Today’s air quality legislation falls short of addressing air quality degradation by biological weather, despite increasing evidence for the feasibility of both mitigation and adaptation policy options. In comparison with the existing capabilities for physical and chemical weather, the monitoring of biological weather is lacking stable operational agreements and resources. Furthermore, integrated effects of physical, chemical, and biological weather suggest a critical review of air quality management practices. Additional research is required to improve the coupled modeling of physical, chemical, and biological weather as well as the assessment and communication of integrated air quality. Findings from several recent COST Actions underline the importance of an increased dialog between scientists from the fields of meteorology, air quality, aerobiology, health, and policy makers.     

Paleoecological Assessment of Watershed History in PRIMENet Watersheds at Acadia National Park, USA

Paleoecological reconstructions of forest stand histories for two upland watersheds at Acadia National Park in Maine were completed to support related watershed chemistry studies. The project hypothesis was that forest type and fire history influence long-term cycling and storage of atmospheric mercury and nitrogen within watersheds. The reconstructions document differences in major vegetation composition and disturbance between the burned and unburned watersheds during the past several centuries. Pollen and charcoal stratigraphies from organic sediment accumulations in forested wet depressions indicate that the present experimental design of contrasting disturbance and forest histories has persisted during recent centuries. The unburned watershed has been dominated by spruce (Picea rubens) and fir (Abies balsamea) for 500 years or more and has not recently burned or been substantially cleared. The burned watershed is dominated by a heterogeneous forest of patchy hardwood, mixed wood, and softwood stands. A large portion of this watershed burned severely in 1947 and probably more than once in the 1800s, and has supported heterogeneous successional forests for 200 years or longer. Overall, these results support the underlying premise that the experimental design of this watershed research can be used to infer landscape controls on biogeochemical processes.     

Division of labor in a dynamic environment: response by honeybees (Apis mellifera) to graded changes in colony pollen stores

 A fundamental requirement of task regulation in social groups is that it must allow colony flexibility. We tested assumptions of three task regulation models for how honeybee colonies respond to graded changes in need for a specific task, pollen foraging. We gradually changed colony pollen stores and measured behavioral and genotypic changes in the foraging population. Colonies did not respond in a graded manner, but in six of seven cases showed a stepwise change in foraging activity as pollen storage levels moved beyond a set point. Changes in colony performance resulted from changes in recruitment of new foragers to pollen collection, rather than from changes in individual foraging effort. Where we were able to track genotypic variation, increases in pollen foraging were accompanied by a corresponding increase in the genotypic diversity of pollen foragers. Our data support previous findings that genotypic variation plays an important role in task regulation. However, the stepwise change in colony behavior suggests that colony foraging flexibility is best explained by an integrated model incorporating genotypic variation in task choice, but in which colony response is amplified by social interactions. Received: 17 October 1998 / Received in revised form: 11 March 1999 / Accepted: 12 March 1999     

Maximum feasible distance of windborne cross-pollination in Brassica napus: A ‘mass budget’ model

A theory of gene dispersal by wind pollination can make an important contribution to understanding the viability and evolution of important plant groups in the Earth's changing landscape and it can be applied to evaluate concerns about the spread of engineered genes from genetically modified (GM) crops into conventional varieties via windborne pollen. Here, we present a model of cross-pollination between plant populations due to the wind. We perform a ‘mass budget’ of pollen by accounting for the number of pollen grains from release in the source population, dispersal from the source to the sink population by the wind, and deposition on receptive surfaces in the sink population. Our model can be parameterised for any wind-pollinated species, but we apply it to Brassica napus (oilseed rape or canola) to investigate the threat posed by wind pollination to GM confinement in agriculture. Specifically, we calculate the maximum feasible distance at which a particular level of windborne gene dispersal could be attained. This is equivalent to the separation distance between populations or fields required to achieve a given threshold of gene dispersal or adventitious GM presence. As required, model predictions of the upper bounds on levels of wind-mediated gene dispersal exceed observations from a wide range of published studies. For a level of gene dispersal below 0.9%, which is the EU threshold for GM adventitious presence, we predict that the maximum feasible distance for agricultural fields of B. napus is 1000 m, regardless of field shape and direction of prevailing winds. For fields closer than 1000 m, our model results do not necessarily imply that the 0.9% threshold is likely to be breached, because in this instance we have conservatively set the values of parameters where current knowledge is limited. We also predict that gene dispersal is reduced by 50% when the lag in peak flowering between the source and sink populations is 13 days, and reduced by 90% when the lag is 24 days. We identify further measurements necessary to improve the accuracy of the model predictions.     

Using dispersion and mesoscale meteorological models to forecast pollen concentrations

This work describes the results of research into a source-oriented pollen concentration forecasting technique. Tests were conducted using the National Center for Atmospheric Research/ Penn State Fifth Generation Mesoscale Model (MM5), the National Oceanographic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT_4) Model combined with the locations of oak trees and their aerial coverage from biogenic emissions land cover database version 3.1 (BELD3). Daily forecasts of pollen concentrations via MM5 and HYSPLIT_4 were made with 30-min increments and tested against 30-min oak pollen data collected by the St. Louis County Department of Health in Clayton, Missouri, for the month of April 2000.Results from these tests show that the combination of MM5 and HYSPLIT_4 with accurate source locations can provide short-term forecasts as indicated by the levels of forecast pollen and actual oak pollen levels, which follow similar profiles for the day. From the 30 individual pollen concentration forecasts, two example forecasts are presented. Additional studies need to be conducted to further validate these results, using an array of pollen collectors. A better understanding of the biology of pollen release is critical to improving these pollen concentration forecasts.     

The effects of colony-level selection on the social organization of honey bee (Apis mellifera L.) colonies: colony-level components of pollen hoarding

Two-way selection for quantities of stored pollen resulted in the production of high and low pollen hoarding strains of honey bees (Apis mellifera L.). Strains differed in areas of stored pollen after a single generation of selection and, by the third generation, the high strain colonies stored an average 6 times more pollen than low strain colonies. Colony-level organizational components that potentially affect pollen stores were identified that varied genetically within and between these strains. Changes occurred in several of these components, in addition to changes in the selected trait. High strain colonies had a significantly higher proportion of foragers returning with loads of pollen, however, high and low strain colonies had equal total numbers of foragers Colony rates of intake of pollen and nectar were not independent. Selection resulted in an increase in the number of pollen collectors and a decrease in the number of nectar collectors in high strain colonies, while the reciprocal relationship occurred in the low strain. High and low strain colonies also demonstrated different diurnal foraging patterns as measured by the changing proportions of returning pollen foragers. High strain colonies of generation 3 contained significantly less brood than did low strain colonies, a consequence of a constraint on colony growth resulting from a fixed nest volume and large quantities of stored pollen. These components represent selectable colony-level traits on which natural selection can act and shape the social organization of honey bee coloniesCommunicated by R.F.A. Moritz     

浊点萃取-原子吸收光谱法测定水和花粉中痕量铜、铅、镉

以氢氧化钠为沉淀剂,依据Triton X-114的浊点现象分离沉淀,沉淀在浓盐酸作用下溶解,用原子吸收光谱法测定样品中痕量铜、铅、镉。通过试验优化测定条件,使该方法在0 mg/L~6.00 mg/L范围内线性良好,3种元素的方法检出限分别为0.028μg/L、0.006μg/L、0.028μg/L。将该方法用于水样、花粉中痕量铜、铅、镉的测定,RSD为2.8%~7.9%,加标回收率为92.0%~106%。     

Effects of protein-constrained brood food on honey bee (<Emphasis Type="Italic">Apis mellifera</Emphasis> L.) pollen foraging and colony growth

Pollen is the sole source of protein for honey bees, most importantly used to rear young. Honey bees are adept at regulating pollen stores in the colonies based on the needs of the colony. Mechanisms for regulation of pollen foraging in honey bee are complex and remain controversial. In this study, we used a novel approach to test the two competing hypothesis of pollen foraging regulation. We manipulated nurse bee biosynthesis of brood food using a protease inhibitor that interferes with midgut protein digestion, significantly decreasing the amount of protein extractable from hypopharyngeal glands. Experimental colonies were given equal amounts of protease inhibitor-treated and untreated pollen. Colonies receiving protease inhibitor treatment had significantly lower hypopharyngeal gland protein content than controls. There was no significant difference in the ratio of pollen to nonpollen foragers between the treatments. Pollen load weights were also not significantly different between treatments. Our results supported the pollen foraging effort predictions generated from the direct independent effects of pollen on the regulation of pollen foraging and did not support the prediction that nurse bees regulate pollen foraging through amount of hypopharyngeal gland protein biosynthesis.     

玉米花粉的营养价值及加工工艺

玉米花粉资源丰富,是一种含高蛋白、多种维生素、微量元素和低脂肪食物,营养价值高,采集加工方便,成本低,对提高人民健康水平和发展经济具有重要作用。