Characteristics of Grass Pollen Seasons in Areas of Southern Spain and the United Kingdom

Spatial and temporal variations in daily grass pollen counts and weather variables are described for two regions with different bio-geographical and climatic regimes, southern Spain and the United Kingdom. Daily average grass pollen counts are considered from six pollen-monitoring sites, three in southern Spain (Ciudad Real, Córdoba and Priego) and three in the United Kingdom (Edinburgh, Worcester and Cambridge). Analysis shows that rainfall and maximum temperatures are important factors controlling the magnitude of the grass pollen season in both southern Spain and the United Kingdom, and that the strength and direction of the influence exerted by these variables varies with geographical location and time.

Are the Birch Trees in Southern England a Source of Betula Pollen for North London?

Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts (n=60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200–0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

Reform, Standards and Teacher Identity: Challenges of Sustaining Commitment

Teacher commitment has been found to be a critical predictor of teachers’ work performance, absenteeism, retention, burnout and turnover, as well as having an important influence on students’ motivation, achievement, attitudes towards learning and being at school (Firestone (1996). Educational Administration Quarterly, 32(2), 209–235; Graham (1996). Journal of Physical Education, Recreation and Dance, 67(1), 45–47; Louis (1998). School Effectiveness and School Improvement, 9(1), 1–27; Tsui & Cheng (1999). Educational Research and Evaluation, 5(3), 249–268). It is also a necessary ingredient to the successful implementation, adaptation or resistance reform agendas. Surprisingly, however, the relationship between teachers’ motivation, efficacy, job satisfaction and commitment, and between commitment and the quality of their work has not been the subject of extensive research. Some literature presents commitment as a feature of being and behaving as a professional (Helsby, Knight, McCulloch, Saunders, & Warburton (1997). A report to participants on the professional cultures of Teachers Research Project, Lancaster University, January). Others suggest that it fluctuates according to personal, institutional and policy contexts (Louis (1998). School Effectiveness and School Improvement, 9(1), 1–27) and identify different dimensions of commitment which interact and fluctuate (Tyree (1996). Journal of Educational Research, 89(5), 295–304). Others claim that teachers’ commitment tends to decrease progressively over the course of the teaching career (Fraser, Draper, & Taylor (1998). Evaluation and Research in Education, 12 (2), 61–71; Huberman (1993). The lives of teachers. London: Cassell). In this research, experienced teachers in England and Australia were interviewed about their understandings of commitment. The data suggest that commitment may be better understood as a nested phenomena at the centre of which is a set of core, relatively permanent values based upon personal beliefs, images of self, role and identity which are subject to challenge by change which is socio-politically constructed.

Improvement in the Accuracy of Back Trajectories Using WRF to Identify Pollen Sources in Southern Iberian Peninsula

Airborne pollen transport at micro-, meso-gamma and meso-beta scales must be studied by atmospheric models, having special relevance in complex terrain. In these cases, the accuracy of these models is mainly determined by the spatial resolution of the underlying meteorological dataset. This work examines how meteorological datasets determine the results obtained from atmospheric transport models used to describe pollen transport in the atmosphere. We investigate the effect of the spatial resolution when computing backward trajectories with the HYSPLIT model. We have used meteorological datasets from the WRF model with 27, 9 and 3 km resolutions and from the GDAS files with 1 ° resolution. This work allows characterizing atmospheric transport of Olea pollen in a region with complex flows. The results show that the complex terrain affects the trajectories and this effect varies with the different meteorological datasets. Overall, the change from GDAS to WRF-ARW inputs improves the analyses with the HYSPLIT model, thereby increasing the understanding the pollen episode. The results indicate that a spatial resolution of at least 9 km is needed to simulate atmospheric flows that are considerable affected by the relief of the landscape. The results suggest that the appropriate meteorological files should be considered when atmospheric models are used to characterize the atmospheric transport of pollen on micro-, meso-gamma and meso-beta scales. Furthermore, at these scales, the results are believed to be generally applicable for related areas such as the description of atmospheric transport of radionuclides or in the definition of nuclear-radioactivity emergency preparedness.