bluuebunny/crossref_metadata_2025 huggingface dataset:
Vadose zone infiltration rate at Hanford, Washington, inferred from Sr isotope measurements
Authors: Maher Katharine , DePaolo Donald J. , Conrad Mark E. , Serne R. Jeff
Published: August 2003

Sr isotope ratios were measured in the pore water, acid extracts, and sediments of a 70‐m vadose zone core to obtain estimates of the long‐term infiltration flux for a site in the Hanford/DOE complex in eastern Washington State. The 87Sr/86Sr values for the pore waters decrease systematically with depth, from a high value of 0.721 near the surface toward the bulk sediment average value of 0.711. Estimates of the bulk weathering rate combined with Sr isotopic data were used to constrain the long‐term (century to millenial scale) natural diffuse infiltration flux for the site given both steady state and nonsteady state conditions. The models suggest that the infiltration flux for the site is 7 ± 3 mm/yr. The method shows potential for providing long‐term in situ estimates of infiltration rates for deep heterogeneous vadose zones.
A technique for generating regional climate scenarios using a nearest‐neighbor algorithm
Authors: Yates David , Gangopadhyay Subhrendu , Rajagopalan Balaji , Strzepek Kenneth
Published: August 2003

A K‐nearest neighbor (K‐nn) resampling scheme is presented that simulates daily weather variables, and consequently seasonal climate and spatial and temporal dependencies, at multiple stations in a given region. A strategy is introduced that uses the K‐nn algorithm to produce alternative climate data sets conditioned upon hypothetical climate scenarios, e.g., warmer‐drier springs, warmer‐wetter winters, and so on. This technique allows for the creation of ensembles of climate scenarios that can be used in integrated assessment and water resource management models for addressing the potential impacts of climate change and climate variability. This K‐nn algorithm makes use of the Mahalanobis distance as the metric for neighbor selection, as opposed to a Euclidian distance. The advantage of the Mahalanobis distance is that the variables do not have to be standardized nor is there a requirement to preassign weights to variables. The model is applied to two sets of station data in climatologically diverse areas of the United States, including the Rocky Mountains and the north central United States and is shown to reproduce synthetic series that largely preserve important cross correlations and autocorrelations. Likewise, the adapted K‐nn algorithm is used to generate alternative climate scenarios based upon prescribed conditioning criteria.
Modes of the wintertime Arctic temperature variability
Authors: Semenov Vladimir A. , Bengtsson Lennart
Published: August 2003

It is shown that the Arctic averaged wintertime temperature variability during the 20th century can be essentially described by two orthogonal modes. These modes were identified by an Empirical Orthogonal Function (EOF) decomposition of the 1892–1999 surface wintertime air temperature anomalies (40°N–80°N) using a gridded dataset covering high Arctic. The first mode (1st leading EOF) is related to the NAO and has a major contribution to Arctic warming during the last 30 years. The second one (3rd leading EOF) dominates the SAT variability prior to 1970. A correlation between the corresponding principal component PC3 and the Arctic SAT anomalies is 0.79. This mode has the largest amplitudes in the Kara‐Barents Seas and Baffin Bay and exhibits no direct link to the large‐scale atmospheric circulation variability, in contrast to the other leading EOFs. We suggest that the existence of this mode is caused by long‐term sea ice variations presumably due to Atlantic inflow variability.
Bubble size distributions in a convecting layer
Authors: Namiki Atsuko , Hatakeyama Tadahiro , Toramaru Atsushi , Kurita Kei , Sumita Ikuro
Published: August 2003

We have conducted a series of laboratory experiments to explore the bubble size distribution coupled with convection in a magma chamber. Boiling liquid heated from below exhibits two types of convection pattern depending on the viscosity. When the viscosity is sufficiently high, bubbles are distributed uniformly in the liquid, and the bubble size distribution becomes the power law type for large bubbles and exponential distribution for small bubbles. On the other hand, when the viscosity is low, bubbles are separated from the liquid layer, making a foam, and their size distribution is exponential for large bubbles and unimodal for small bubbles. These experimental results suggest that the bubble size distribution is determined whether the viscous drag of the magma is sufficiently high to trap bubbles.
An unknown active fault revealed by microseismicity in the south‐east of France
Authors: Courboulex Françoise , Larroque Christophe , Deschamps Anne , Gélis Céline , Charreau Julien , Stéphan Jean‐François
Published: August 2003

A seismic swarm occurred in the south‐east of France in December 2000, about 15 km north of the densely populated cities of the French‐Riviera. More than 300 events were located by a dense temporary seismic network that had been installed in the epicentral region one month before. We evidence an alignment of the seismicity that we interpret as an unknown active fault. On the basis of regional tectonics, we propose that this fault results from basement faulting cutting through the detached overlying sedimentary cover.
Properties of jet engine combustion particles during the PartEmis experiment. Hygroscopic growth at supersaturated conditions
Authors: Hitzenberger R. , Giebl H. , Petzold A. , Gysel M. , Nyeki S. , Weingartner E. , Baltensperger U. , Wilson C. W.
Published: August 2003

During the EU Project PartEmis, the microphysical properties of aircraft combustion aerosol were investigated. This study is focused on the ability of exhaust aerosols to act as cloud condensation nuclei (CCN). The combustor was operated at two different conditions representing old and modern aircraft engine technology. CCN concentrations were measured with the University of Vienna CCN counter [Giebl et al., 2002] at supersaturations around 0.7%. The activation ratio (fraction of CCN in total aerosol) depended on the fuel sulphur content (FSC) and also on the operation conditions. CCN/CN ratios increased from 0.93 through 1.43 to 5.15 · 10−3 (old cruise conditions) and 0.67 through 3.04 to 7.94 · 10−3 (modern cruise conditions) when FSC increased from 50 through 410 to1270 μg/g. The activation behaviour was modelled using classical theories and with a semi‐empirical model [Gysel et al., 2003] based on measured hygroscopicity of the aerosol under subsaturated conditions, which gave the best agreement.
Evolution of biomass burning aerosol properties from an agricultural fire in southern Africa
Authors: Abel Steven J. , Haywood Jim M. , Highwood Eleanor J. , Li Jia , Buseck Peter R.
Published: August 2003

Measurements on the UK Met Office C‐130 within a distinct biomass burning plume during the Southern AFricAn Regional science Initiative (SAFARI 2000) show an increase in the single scattering albedo as the aerosol ages, from 0.84 at source to 0.90 in the aged regional haze in 5 hours. Condensation of scattering material from the gas phase appears to be the dominant mechanism; the change in black carbon morphology, from a chain to clump like structure, does not significantly affect the bulk aerosol single scattering albedo.
Predicting land‐surface climates‐better skill or moving targets?
Authors: Henderson‐Sellers A. , Irannejad P. , McGuffie K. , Pitman A. J.
Published: August 2003

Uncertainty in the prediction of continental surface climates is identified by the Intergovernmental Panel on Climate Change (IPCC) as limiting our confidence in projecting future climates. To reduce this uncertainty, the Atmospheric Model Intercomparison Project (AMIP) Diagnostic Subproject 12 (DSP 12) and the Project for Intercomparison of Land‐surface Parameterisation Schemes (PILPS) have used a substantially improved experimental design, coupled with a greater variety of land‐surface schemes (LSSs) represented in AMIP II, to investigate whether the thirty years of effort in land surface modelling has led to improvements in simulations of continental surface processes. In AMIP II, we find a clear chronological sequence of: First generation ‘no canopy’; second generation ‘SiBlings’; and ‘recent schemes’. We conclude that three decades have improved continental surface modelling capability but that full confidence in our ability to project land‐surface quantities using climate models remains elusive, in part due to uncertainties in surface observations.
Cold halocline, increased nutrients and higher chlorophyll off Oregon in 2002
Authors: Wheeler Patricia A. , Huyer Adriana , Fleischbein Jane
Published: August 2003

Observed changes in the nutrient levels in the halocline of the California Current during 2002 indicated a natural eutrophication that was accompanied by increased chlorophyll and oxygen in surface water. Decreased oxygen in the lower water column over the shelf indicated that much of the phytoplankton production was respired rather than passed on to higher trophic levels. In 2002 the halocline water was >1°C colder than usual and 0.5°C colder than any previous observation. Four transect lines off the coast of Oregon show a 50% increase in nitrate, phosphate and silicate at 33 psu in 2002 compared to 1998–2001. The increase in nutrients resulted in a 2‐fold increase in chlorophyll standing stocks during the summer of 2002 compared with the preceding four years. A significant portion of the increased production was subsequently respired resulting in low oxygen water over the shelf.
Measurements and models of the atmospheric Ar/N2 ratio
Authors: Battle Mark , Bender Michael , Hendricks Melissa B. , Ho David T. , Mika Robert , McKinley Galen , Fan Song‐Miao , Blaine Tegan , Keeling Ralph F.
Published: August 2003

The Ar/N2 ratio of air measured at 6 globally distributed sites shows annual cycles with amplitudes of 12 to 37 parts in 106. Summertime maxima reflect the atmospheric Ar enrichment driven by seasonal warming and degassing of the oceans. Paired models of air‐sea heat fluxes and atmospheric tracer transport predict seasonal cycles in the Ar/N2 ratio that agree with observations, within uncertainties.
Wind‐driven shelf/basin exchange on an Arctic shelf: The joint roles of ice cover extent and shelf‐break bathymetry
Authors: Carmack Eddy , Chapman David C.
Published: August 2003

The efficiency of shelf/basin exchange (SBE) in polar regions during summer is strongly moderated by the location of the ice edge relative to underlying topography. Numerical model calculations suggest that upwelling‐favorable winds generate very little SBE so long as the ice edge remains shoreward of the shelf break, but an abrupt onset of shelf‐break upwelling takes place when the ice edge retreats beyond the shelf break. A climatology (1968–2000) of ice conditions from the Canadian Shelf of the Beaufort Sea shows large interannual variability in ice edge extent and duration of ice‐free conditions in summer. Similarly, available hydrographic data reflect a corresponding variability in water mass properties. Under scenarios of climate warming associated with greenhouse gas build‐up, both the extent and duration of summer melt‐back are predicted to increase, and this may have dramatic impacts on SBE and biological productivity.
New insight in the Hawaiian plume swell dynamics from scaling laws
Authors: van Hunen Jeroen , Zhong Shijie
Published: August 2003

The formation and shape variation of the Hawaiian plume swell is re‐examined numerically. Scaling laws for the plume buoyancy flux and swell width and height help gaining new insight in relationships between swell formation and relevant model parameters, like plume temperature and size, and mantle rheology. A scaling law for the plume buoyancy F = Aη0−1.2Rp3.5ΔTp2.2 exp(1.3 × 10−8EΔTp), with background mantle viscosity η0, plume radius Rp, plume excess temperature ΔTp, and activation energy E fits numerical flux measurements within 8%. Scaling laws for the swell width and height have similar forms, and their multiplication resembles the buoyancy flux scaling law within 10%. These scaling laws suggest that the background mantle viscosity plays a significant role, and that the increased Hawaiian plume intensity ∼25 Ma ago is due to a plume excess temperature increase of 50%.
Annual layers in polar firn detected by Borehole Optical Stratigraphy
Authors: Hawley Robert L. , Waddington Edwin D. , Alley Richard B. , Taylor Kendrick C.
Published: August 2003

We have developed a system called Borehole Optical Stratigraphy which can detect annual layers in boreholes in polar firn. Borehole Optical Stratigraphy consists of a downhole camera package and post‐processing routines, which allow us to measure the intensity of light emitted from an on‐board source and returned from the borehole wall. We manually identify the annual layers in this optical signal. We used this system at Siple Dome, Antarctica, in the 2001–2002 austral summer season. Our results agree well with counts of annual layers detected with two different methods in an ice core recovered 50 meters from our borehole.
Day‐to‐day variations of migrating diurnal tide simulated by a GCM from the ground surface to the exobase
Authors: Miyoshi Yasunobu , Fujiwara Hitoshi
Published: August 2003

A new general circulation model (GCM) which contains the region from the ground surface to the exobase has been developed and used to investigate behavior of the migrating diurnal tide for equinox during solar cycle minimum and geomagnetically quiet conditions. In particular, we study day‐to‐day variations of migrating diurnal tides in the mesosphere and thermosphere and their relation with migrating diurnal tides generated in the lower atmosphere. The results show that day‐to‐day variations of the migrating diurnal tide are evident from the upper troposphere to the thermosphere. Fluctuations of the migrating diurnal amplitude with periods of 12 and 25 days are found in the height range from 20 to 300 km, indicating dynamical coupling between the mesosphere and thermosphere and the lower atmosphere.
Stresses in the Vanuatu subducting slab: A test of two hypotheses
Authors: Christova Cenka , Scholz Christopher H.
Published: August 2003

Stress inversions of intermediate‐depth focal mechanisms in Vanuatu were used to test two hypotheses: that the slab acts as a stress guide and whether intermediate‐focus earthquakes occur on preexisting faults. Although the strike of the Vanuatu slab varies by over 70°, the maximum compression σ1 is everywhere slab normal and the least compression σ3 is everywhere within the plane of the slab. This provides strong confirmation of the stress guide hypothesis. In the depth range 61–120 km, the solution space for σ3 forms a girdle pattern in the plane of the slab, indicating bi‐axial tension. This gradually changes to down‐dip tension at greater depth. We find that preexisting faults may become reactivated by intermediate depth earthquakes but only when the slab stresses favor it: Otherwise new faults are formed. This contradicts the idea that the mechanism of intermediate focus earthquakes requires serpentinite dehydration on preexisting faults.
Solubility and freezing effects of Fe2+ and Mg2+ in H2SO4 solutions representative of upper tropospheric and lower stratospheric sulfate particles
Authors: Wise Matthew E. , Brooks Sarah D. , Garland Rebecca M. , Cziczo Daniel J. , Martin Scot T. , Tolbert Margaret A.
Published: August 2003

Chemical elements characteristic of earth minerals and meteorites are present within background tropospheric and stratospheric sulfate aerosol particles. However, it is unknown if these elements are present predominantly as solids, including possible sulfates, carbonates, and oxides, or rather as soluble aqueous metal ions or complexes. Further, it is unclear how these impurities could affect particle freezing. To address these questions, we have determined the total equilibrium metal solubility ([Fe2+]T and [Mg2+]T) in 20–90 wt % sulfuric acid solutions over the temperature range 200–300 K. We have measured solubilities using samples of MgSO4, FeSO4·7H2O, and a mixture of metal sulfates representative of some meteorite samples. Because Fe2+ oxidation by O2 was found to be negligible over a 28 day period when air was bubbled through the solutions, we conclude that aqueous Fe2+ may be present at high concentrations in atmospheric sulfuric acid particles. We estimate that soluble Fe2+ and Mg2+ compose ∼0.01–0.28 wt % of the H2SO4/H2O/{Fe2+, Mg2+} solutions at temperatures and acid compositions representative of the atmosphere. Compared to composition measurements done by mass spectrometry of atmospheric particles showing ∼0.75 wt % Fe and 0.20 wt % Mg, we conclude it is plausible that solid Fe2+ and Mg2+ minerals often occur inside atmospheric sulfuric acid particles. Bulk freezing experiments were also carried out on H2SO4 solutions containing amounts of dissolved metal determined by the low‐temperature solubility studies. It was found that 57.6 wt % H2SO4 containing soluble meteoritic metal and 60 wt % H2SO4 containing either soluble Fe or soluble meteoritic metal froze ∼12–20 K higher than solutions containing no soluble metal. Soluble metal ions in sulfuric acid solution may therefore provide a mechanism for sulfuric acid tetrahydrate formation in the lower stratosphere.
Sensitivity study of meteorological parameters on mineral aerosol mobilization, transport, and distribution
Authors: Luo Chao , Mahowald Natalie M. , del Corral John
Published: August 2003

Predicting mineral aerosol distributions is a difficult task due to the episodic nature of the sources and transport. Here we show comparisons between a 22‐year simulation of mineral aerosols and satellite and in situ observations. Our results suggest that the model does a good job of predicting atmospheric mineral aerosol distributions, with some discrepancies. In addition, there are differences between our model results and previously published results [e.g., Ginoux et al., 2001]. We conduct several tests of the sensitivity of mineral aerosol simulations to the meteorological data sets and mobilization parameterizations in order to understand the differences. Comparisons between model simulations using National Center for Atmospheric Research/National Center for Environmental Prediction (NCEP/NCAR) and National Aeronautics and Space Administration Data Assimilation Office (NASA DAO) reanalysis data sets show that the model results with the two data sets are fairly consistent but with some important differences. The sensitivity analysis shows that differences between simulated dust near Australia are likely due to differences in both source parameterization and surface winds. Differences over East Asia are dominated by differences in meteorology. The sensitivity analysis also shows that we cannot tell from comparisons with observations whether the cultivation source is active nor eliminate it because of the large uncertainty in meteorology and source parameterization.
Synthesis inverse mapping method applied to the retrieval of aerosol size distributions from extinction measurements
Authors: Fussen Didier , Vanhellemont Filip , Bingen Christine
Published: August 2003

The problem of inverting aerosol extinction data in the near‐UV to near‐IR range to retrieve aerosol size distributions is addressed by means of a recently developed method called “synthesis inverse mapping.” The rationale and the algebra of the method are developed, and the full error budget is discussed. The performance of the algorithm is evaluated with respect to standard monomodal and bimodal distributions published in the literature. The new method allows error amplification control and estimation of the smoothing error, and it is well suited for operational fast retrieval.
Pet‐keeping in early childhood and airway, nose and skin symptoms later in life
Authors: Bornehag C. G. , Sundell J. , Hagerhed L. , Janson S. ,   the DBH Study Group
Published: August 2003

Background: It is discussed whether exposure to pets during childhood is a risk or a protective factor for sensitization and allergic symptoms. The aim of this study was to investigate the association between pet‐keeping at time of birth and allergic symptoms in airways, nose and skin among young children in Sweden.

Method: A questionnaire was sent to the parents of 14 077 children (1–6 years), the focus being on allergic symptoms, home environment and other background factors including pet‐keeping and avoidance behaviour. The response rate was 79%.

Results: Almost one‐tenth of the population had got rid of pets because of allergy in the family, and 27.3% reported ‘avoidance’ behaviour towards pets. In a cross‐sectional analysis current pet‐keeping was ‘protective’, but this may be due to the fact that people avoid exposing their child to something that they believe is a risk factor for allergies. Pet‐keeping at the time of birth was associated with ‘wheezing’, ‘asthma’ and ‘rhinitis on pet‐exposure’ later in life for children from families with an ‘avoidance’ behaviour, and was not ‘protective’ for other children. There was also an indication of a dose–response relationship between the number of types of furred pets at time of birth and later symptoms in analyses adjusted for avoidance behaviour or current pet‐keeping.

Conclusion: The distribution of pet‐keeping in the population is largely explained by avoidance behaviour, meaning that those who have pets mainly are those who can stand them, indicating a ‘healthy pet‐keeping effect’.
Characterization of airway nitric oxide in allergic rhinitis: The effect of intranasal administration of l‐NAME
Authors: Palm J. P. , Alving K. , Lundberg J. O.
Published: August 2003

Background:  Several studies have attempted to assess nasal nitric oxide (NO) levels in allergic rhinitis (AR). However, there seem to be differences in the results obtained. We therefore wanted to investigate this further by studying airway NO in AR and controls at several modalities, and also the effect of intranasal administration of the nitric oxide synthase (NOS) inhibitorNG‐nitro‐l‐arginine‐methyl ester·HCl (l‐NAME).

Methods:  Airway NO was determined through repeated measurements at three flow rates of air (0.5, 3, and 9 l/min), using a single‐breath method and a method of nasal aspiration, in 18 patients with birch pollen AR during season and in 18 controls.

Results:  Patients with AR were characterized by no difference in nasal but higher orally exhaled NO and a larger interindividual spread in nasal and orally exhaled NO compared to controls. We also found a greater reduction in nasal NO after l‐NAME in patients compared to controls.

Discussion:  These results indicate that several factors determine the levels of nasal NO in rhinitis. NO production in the nasal mucosa of patients with AR may be upregulated. On the other hand, this increase could be counteracted by swelling of the mucosa and secretions resulting in impaired NO diffusion from, for example, the paranasal sinuses, where particularly high levels of NO have been found. Also, the high background levels of NO from constitutive sources in the nose may blunt smaller increases in mucosal NO output.

Conclusion:  It seems that the methods for measurement of nasal NO need to be improved and standardized before we can consider to use this test in monitoring inflammation in AR.
Lack of human IgE cross‐reactivity between mite allergens Blo t 1 and Der p 1
Authors: Cheong N. , Soon S. C. , Ramos J. D. A. , Kuo I. C. , Kolortkar P. R. , Lee B. W. , Chua K. Y.
Published: August 2003

Background:  The group 1 mite allergens are the most significant indoor allergens and they belong to the papain‐like cysteine protease family. To date there is only one published report on the isolation and characterization of group 1 allergens from Blomia tropicalis mites. The aims of the study are to determine the cross‐reactivity between group 1 allergens and to evaluate their clinical importance in allergic patients.

Methods:  The full‐length Blo t 1 gene was obtained by SMARTTM RACE cDNA amplification method using gene‐specific primers. The sequence alignment was performed using LOOK followed by three‐dimensional homology modeling. The cDNA was expressed in Pichia pastoris as a secretory protein. Identification of native Blo t 1 in crude mite and spent mite medium extracts was done by Western immunoblot using monoclonal antibody. Allergenicity of recombinant Blo t 1 and native Der p 1 was examined by human IgE ELISA with 80 asthmatic sera.

Results:  The cDNA sequence consists of 1105 base pairs, including 5′‐ and3′‐untranslating regions, encoding an open reading frame of 330 amino acid residues. The predicted molecular weight of the deduced protein was approximately 38 kDa. Blo t 1 shared 53 and 34% nucleotide and amino acid, respectively, sequence homology with Der p 1. Native Blo t 1 was detected in both crude mite and spent mite medium extracts, and its estimated molecular weight was about 26 kDa. The recombinant Blo t 1 reacted positively with IgE in 90 and 65% of sera from asthmatic children and adults, respectively, indicating that it is a major allergen. The correlation of human IgE reactivity between Blo t 1 and Der p 1 was low in these sera.

Conclusion:  The full‐length cDNA encoding group 1 Blomia tropicalis mite allergen (designated as Blo t 1) has been characterized and expressed from local mites in Singapore. This fecal allergen showed high frequency of human IgE reactivity with asthmatic sera in the tropics and there was a low correlation of IgE reactivity between Blo t 1 and Der p 1.
Role and interpretation of total serum IgE measurements in the diagnosis of allergic airway disease in adults
Authors: Kerkhof M. , Dubois A. E. J. , Postma D. S. , Schouten J. P. , de Monchy J. G. R.
Published: August 2003

Background: While total IgE measurements are often used in clinical practice, it is unclear how they should be interpreted for the diagnosis of allergic disorders. We studied whether total IgE may be used to rule out or predict sensitization and whether there are age or gender differences.

Methods: ROC curves were assessed in subjects with asthma or allergy symptoms from a general population sample. We studied predictive values and likelihood ratios. At least one positive skin test (Phazet®) or specific IgE measurement (CAP®) served as reference.

Results: High negative predictive values, suitable to rule out sensitization, were not found. In younger subjects, high total IgE levels strongly increase the probability of sensitization. The relationship between monosensitization and total IgE was less strong, but meaningful positive likelihood ratios were found at higher levels of total IgE. The discriminating ability of total IgE was better in the age group 20–44 than 45–70 years and comparable in males and females.

Conclusion: Total IgE is not useful to rule out sensitization to common inhalant allergens. High total IgE may indicate a high probability of sensitization and may be useful to decide whether further investigation is warranted in patients with negative specific allergy tests to a panel of common inhalant allergens.
Exposure to high doses of birch pollen during pregnancy, and risk of sensitization and atopic disease in the child
Authors: Kihlström A. , Lilja G. , Pershagen G. , Hedlin G.
Published: August 2003

Background: The role of maternal allergen exposure during pregnancy in sensitization and development of atopic disease in the child remains controversial. In the spring of 1993, extremely high levels of birch pollen were recorded in Stockholm, Sweden. In 1994, the corresponding pollen levels were low. The aim of this study was to assess the influence of exposure during pregnancy to high/low doses of birch pollen on the risk of sensitization and development of atopic disease in children. In addition, a comparison was made with children exposed to birch pollen in early infancy.

Methods: Three hundred and eighty‐seven children with atopic heredity, born in Stockholm in July–October 1993 or 1994 (mothers exposed during pregnancy), were investigated at age 4.5 years. The children were clinically examined and were skin prick tested (SPT) with inhalant and food allergens. IgE antibodies (RAST) against birch pollen and recombinant birch pollen allergen (rBet v 1) were analysed in serum. A comparison was made with a similar group of children exposed during the same incident, but in the first 3 months of life, in 1993.

Results: The children of mothers high‐dose exposed during pregnancy in 1993 tended to be more sensitized (SPT ≥ 3 mm) to birch pollen than the children with low‐dose exposure during the corresponding period in 1994 (7.6 and 4.6%, respectively, OR: 1.7; 95% CI: 0.7–4.1). A similar but weak tendency was seen for positive RAST analyses (≥0.35 kU/l) against birch pollen and rBet v 1. Children of mothers high‐dose exposed during pregnancy were significantly less sensitized to birch pollen than the children high‐dose exposed in early infancy (17.9%, OR: 0.4; 95% CI: 0.2–0.7). There was an overall trend towards a slightly increased prevalence of bronchial asthma, allergic rhinoconjunctivitis and atopic dermatitis in the group with mothers high‐dose exposed during pregnancy, compared to those with low exposure.

Conclusion: Exposure of the mother during pregnancy to high levels of birch pollen resulted in a tendency towards increased risk of sensitization to the same allergen and symptoms of atopic disease in children with atopic heredity. Furthermore, our data indicate that exposure of the mother during pregnancy to inhalant allergens is less likely to result in sensitization in the child than exposure of the child in early infancy.
Association of an early respiratory syncytial virus infection and atopic allergy
Authors: Juntti H. , Kokkonen J. , Dunder T. , Renko M. , Niinimäki A. , Uhari M.
Published: August 2003

Background: Respiratory syncytial virus (RSV) causes postbronchiolitic wheezing but its role in allergic sensitization is controversial. The purpose of the study was to examine the effect of an early RSV infection on allergic sensitization.

Methods: Seventy‐six subjects were examined 6–10 years after hospitalization for RSV infection during the first year of life. Fifty‐one subjects (68%) attended clinical studies and 25 filled in a questionnaire. The study protocol included lung function, skin‐prick and blood tests. The controls were matched for birth date and sex.

Results: Eight per cent of the subjects and 37% of the controls had at least one positive skin‐prick test (SPT) (difference −35%, 95% CI −50 to −19%, P < 0.0001). Allergic rhinitis, atopic dermatitis and asthma occurred as often in both groups, but asthma had been diagnosed significantly earlier in the subjects than in the controls [mean age 3.0 years (SD 2.6) and 5.6 years (SD 3.0), difference 2.6 years, 95% CI 0.57–4.65, P = 0.014]. In a logistic regression analysis, RSV infection was associated with negative SPTs.

Conclusions: An early RSV infection results in reduction of SPT positivity but not of occurrence of atopic diseases. This finding might explain why there is less atopic sensitization in countries with a greater probability of acquiring RSV infection at an early age.
15‐Year aeroallergen records. Their usefulness in Athens Olympics, 2004
Authors: Gioulekas D. , Damialis A. , Papakosta D. , Syrigou A. , Mpaka G. , Saxoni F. , Patakas D.
Published: August 2003

Introduction: About 5–25% of 16 000 athletes involved in preparation for the Athens 2004 Olympics may encounter respiratory allergy (asthma and rhinoconjunctivitis) triggered by exposure to aeroallergens (pollen and fungi spores).

Aim: Provide information about circulating aeroallergens in three Olympic cities and ensure safety for the allergic athletes who will visit Greece from January to September 2004.

Methods: Aeroallergens were recorded using a Burkard volumetric trap. The most frequently implicated pollen (cypress, hazel, wall pellitory, plane, olive, grasses, goosefoot and mugwort) and fungi spores (Alternaria spp., Cladosporium spp.) are presented. These data derive from a 15‐year database created by the Pulmonary Department, Thessaloniki, a 2‐year database (University of Heraklion‐Crete) and a 6‐year database by the Pediatric Department, Athens. The above data and the current aeroallergen counts will be continuously announced by the mass media and Internet during the Athens 2004 Olympics.

Results: Are expressed as: (A) Presentation (Graphs, Tables) of the fluctuation of mean daily values of pollen grains or fungi spores/m3. (B) Presentation (Tables) of the start, peak and end time of aeroallergen circulation. Peak pollen concentrations were observed between March and May (athletes preparation time). During the 2004 Olympics (August–September) relatively high concentrations of goosefoot, mugwort, Alternaria and Cladosporium will be observed. Aeroallergens circulate in Athens 10–15 days earlier than in Thessaloniki and 10 days later than in Heraklion.

Conclusions: The data presented in the study are expected to help allergic Olympic athletes achieve peak performance under prophylactic measures.
Relationship between cutaneous allergen response and airway allergen‐induced eosinophilia
Authors: Boulay M.‐E. , Lemieux M.‐C. , Deschesnes F. , Boulet L.‐P.
Published: August 2003

Background: Determinants of changes in airway caliber after allergen challenge include nonallergic airway responsiveness, immune response and dose of allergen given. However, determinants of the airway inflammatory response to allergens remain to be determined.

Aim: To assess the relationship between skin reactivity to airborne allergens and lower airway eosinophilic response to allergen exposure in asthma and allergic rhinitis.

Methods: Forty‐two subjects with mild allergic asthma (mean age 24 years) and 14 nonasthmatic subjects with allergic rhinitis (mean age 25 years) had allergen skin prick tests and titration with the allergen chosen for subsequent challenge. On a second visit, 31 asthmatic subjects had a conventional challenge while 11 asthmatic subjects and all rhinitic subjects had a low‐dose allergen challenge over four subsequent days. Induced sputum samples were obtained at 6 and 24 h after the conventional challenge and at days 2 and 4 of the low‐dose challenge.

Results: In the asthmatic group, there was a weak correlation between wheal diameter induced by the concentration used for challenge and increase in eosinophils 6 h postconventional challenge (r = 0.372, P = 0.05), but no correlation was observed following the low‐dose challenge. Rhinitic subjects showed a correlation between wheal diameter with the allergen dose used for bronchoprovocation and increase in eosinophils at day 2 of low dose (r = 0.608, P = 0.02).

Conclusion: This study suggests that immediate immune responsiveness to allergen, assessed by the magnitude of the skin response, is a significant determinant of allergen‐induced airway eosinophilia and can help to predict the airway inflammatory response.
Diagnostic value of scratch‐chamber test, skin prick test, histamine release and specific IgE in birch‐allergic patients with oral allergy syndrome to apple
Authors: Osterballe M. , Scheller R. , Skov P. Stahl , Andersen K. E. , Bindslev‐Jensen C.
Published: August 2003

Background: The aim of the study was to examine the diagnostic value of skin prick test (SPT), scratch‐chamber test (SCT), histamine release (HR) and specific immunoglobulin E (IgE) in birch‐allergic patients with oral allergy syndrome to apple.

Methods: Ten birch‐allergic patients with oral allergy syndrome to apple and 10 control subjects were included. All were tested with SPT, SCT, HR and specific IgE [CAP, Pharmacia, Sweden and Magic Lite (ML), ALK‐ABELLÓ, Denmark].

Results: The SPT with apple, acetone extract of apple (A72) and commercial apple extract showed sensitivities of 0.80, 0.90 and 0.10, respectively.

The SCT with the same extracts showed sensitivities of 0.30, 0.50 and 0.20, respectively. The sensitivity of specific IgE to apple were 0.90 (CAP) and 0.10 (ML).

The sensitivity of the HR test was 90% (A72), and 25% using the commercial extract.

Conclusion: The SPT and HR test with apple and A72 showed a good diagnostic value with a sensitivity of more than 70% and a specificity of 100%.

The SCT showed a poor sensitivity to apple, A72 and commercial apple extract. The ML test was not suitable in detecting specific IgE to apple compared with the CAP test.

In daily practice a detailed case history about symptoms of oral allergy syndrome combined with a SPT with fresh apple peel or A72 will be useful.
Broad‐scale biodiversity pattern of the endemic tree flora of the Western Ghats (India) using canonical correlation analysis of herbarium records
Authors: Gimaret‐Carpentier C. , Dray S. , Pascal J.‐P.
Published: August 2003

A crucial step in understanding the origin and maintenance of biological diversity is the assessment of its distribution over space and time and across environmental gradients. At the regional scale, two important attributes of species can be assessed that provide insight into speciation processes: species geographical and environmental ranges. The endemic tree flora of the Western Ghats is an interesting case for analyzing broad‐scale biodiversity patterns because of the steep environmental gradients that characterize this tropical region of India. We analysed species geographical and environmental ranges by Canonical Correlation Analysis of point data from herbarium collections. We performed partial analyses to discriminate spatial and environmental correlates of species distribution, and evaluate the contribution of higher taxonomic ranks to these ranges. We identified different levels of organization in the distribution of endemism: 1) general features, such as the concentration of endemic species in the southern part of the Western Ghats, and the decrease in endemic species richness along the altitudinal and the dry season length gradients, and 2) patterns specific to genera or families, such as species niche separation along the environmental gradients. Our analyses enabled us to formulate hypotheses about the diversification of the endemic tree flora of the Western Ghats. They also confirm the value of Canonical Correlation Analysis as the suitable method for collection data analysis.
How do paedomorphic newts cope with lake drying?
Authors: Denoël Mathieu
Published: August 2003

Paedomorphosis, in which adult individuals retain larval traits, is widespread in newts and salamanders. Most evolutionary models predict the maintenance of this life‐history trait in favourable aquatic habitats surrounded by hostile terrestrial environments. Nevertheless, numerous ponds inhabited by paedomorphic individuals are unpredictable and temporary. In an experimental framework, I showed that paedomorphic newts were able to metamorphose and thus survive in the absence of water. However, the mere decrease of water level or the life space do not seem to induce metamorphosis in paedomorphs. On the contrary, drying up induces almost all individuals to move on land and after that to colonize other aquatic sites located nearby. Such terrestrial migrations allow survival in drying conditions without metamorphosis as long as the distances of terrestrial migration are short. These results are consistent with the presence of paedomorphs in drying ponds and are in favor of classic optimality models predicting metamorphosis in unfavorable environments.
Changes in carabid beetle assemblages across an urban‐rural gradient in Japan
Authors: Ishitani M. , Kotze D. J. , Niemelä J.
Published: August 2003

As part of the international Globenet project, carabid beetles (Coleoptera, Carabidae) were collected using pitfall traps from four urban, four suburban and four rural sites in Hiroshima City, Japan, during the 2001 summer season. In agreement with expectation, carabid abundance and species richness decreased significantly from rural to urban sites. Furthermore, no large, and only few individuals of medium‐sized specialist species were collected from the urban environment, while many specimens of medium‐sized and some large‐sized specialist species were collected from the suburban and rural sites. Hiroshima city was characterised by medium‐sized generalist carabids, while the suburbs and the rural environments were characterised by small‐sized generalist beetles. These results did not apply at the species level. To summarise, we found a significant effect of urbanisation on the composition of carabid beetle assemblages in Hiroshima City. These changes were similar to those found in previous studies performed in Sofia (Bulgaria), Edmonton (Canada) and Helsinki (Finland). Thus, it appears that urbanisation has some similar and predictable effects on carabid assemblages in various parts of the world.
Impact of reindeer grazing on ground‐dwelling Carabidae and Curculionidae assemblages in Lapland
Authors: Suominen Otso , Niemelä Jari , Martikainen Petri , Niemelä Pekka , Kojola Ilpo
Published: August 2003

Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground‐dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H’) of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H’/H'max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites.
The saproxylic beetleBolitophagus reticulatus: its frequency in managed forests, attraction to volatiles and flight period
Authors: Jonsell Mats , Schroeder Martin , Larsson Therese
Published: August 2003

Reduction in amount of dead trees in Scandinavian forests due to intensive forest management has aroused interest in the requirements of saproxylic (wood‐living) species. Much attention has been focused onBolitophagus reticulatus, a tenebrionid beetle that lives on polypore fruiting bodies ofFomes fomentarius. Although earlier studies have suggested that the species has limited dispersal abilities, the beetle is abundant and widely distributed in Swedish forests. To resolve this paradox we conducted a series of field experiments. Firstly, the frequency of the species was found to be similar in six forest stands with a low density of fruiting bodies and six stands with a high density. Secondly, flying individuals were caught in window traps placed in all of eight randomly chosen, well‐managed pine stands. Thirdly, we tested volatiles that flying beetles may use to find hosts by baiting window traps. We found strong attractions to ethanol and to a combination of ethanol and fruiting body. The dispersal period was almost entirely restricted to one week during the summer. Our results suggest thatB. reticulatusis distributed wherever the host occurs. Long distance dispersal ofB. reticulatusis difficult to observe, but appears to be effective when it does occur. Previously observed patchy distribution patterns of the species are probably due to short‐distance movements being more frequent than long‐distance movements. A general conclusion is that interpretations based on mark‐recapture data and indirect measures of substrate and beetle occurrences that claims limited dispersal should be treated with caution.
Differential drift and parasitism in invading and native Gammarus spp. (Crustacea: Amphipoda)
Authors: MacNeil Calum , Dick Jaimie T. A. , Hatcher Melanie J. , Dunn Alison M.
Published: August 2003

Invading and native species often interact directly, such as by predation, producing patterns of exclusion and coexistence. Less direct factors, such as interactions with the broader abiotic and biotic environment, may also contribute to such patterns, but these have received less recognition. In Northern Ireland, the North American Gammarus tigrinus has invaded freshwaters populated with the native Gammarus duebeni celticus, with intraguild predation between the two implicated in their relative success. However, these species also engage in day and night “drifting”, an activity that subjects amphipods to intense predation from fish and wildfowl. Sampling of two rivers where the invader and native co‐occur showed that, compared with the benthos, G. tigrinus was underrepresented and G. d. celticus overrepresented in the drift. In addition, G. tigrinus were free from parasites, whereas some G. d. celticus harboured the acanthocephalans Polymorphus minutus and Echinorhynchus truttae and the muscle wasting microsporidian Pleistophora sp. (new species). Compared with the benthos, G. d. celticus parasitized with P. minutus were overrepresented and unparasitized individuals underrepresented in the drift. The opposite pattern was found with Pleistophora sp. In laboratory experiments, G. tigrinus were less positively phototropic and less “active” than G. d. celticus (unparasitized animals). Polymorphus minutus increased G. d. celticus positive phototropism and activity, while Pleistophora sp. increased positive phototropism but decreased activity. Previous studies show that the invader G. tigrinus is more disadvantaged by intraguild predation from the native G. d. celticus than vice versa. However, the native appears more disadvantaged with respect to drift, parasitism and the interaction of the two. These factors may mitigate direct interactions and help explain complex patterns of coexistence between these invader and native species.