N. van Leeuwen

The impact of canopy exchange on differences observed between atmospheric deposition and throughfall fluxes

To study the impact of canopy exchange on differences observed between atmospheric deposition and throughfall fluxes, several-held experiments were performed at the Speulder forest in The Netherlands. Relevant information was obtained by (i) measuring open-field precipitation and throughfall fluxes with different time resolutions, using two canopy exchange models, (ii) by comparing results from surface wash experiments using real and artificial twigs, respectively, and (iii) by comparing throughfall flux estimates with atmospheric deposition estimates from micrometeorological measurements and inferential modelling. Canopy uptake of gases through stomata was estimated using measured air concentrations and a stomatal conductance model. Specific information on canopy leaching of soil-derived sulphate was provided by a S-35 tracer experiment. Sulphur was found to behave conservatively within the canopy, with SO2 uptake more or less balancing leaching of soil-derived SO42-. Significant stomatal uptake of NO2, HNO2 and NH3 was calculated as well as uptake of H+ and NH4+ from water layers covering the tree surface. Experiments did not indicate significant uptake of NO3- in solution. Canopy uptake of H+ and NH4+ was countered by leaching of K+, Ca2+ and Mg2+. Part of the leaching of K+, Ca2+ and Mg2+ (15%) took place along with weak organic acids. No significant canopy exchange was found for Na+ and Cl-. Differences observed between atmospheric deposition and throughfall fluxes could almost completely be explained by canopy exchange, the difference between NOy deposition and NO3- throughfall flux being the only exception. Copyright (C) 1996 Elsevier Science Ltd (Less)

Fog deposition on a coniferous forest in The Netherlands

Fog deposition in December 1992 and February 1993 (two periods of several days in which fog occurred) was monitored at the location Speulderbos in The Netherlands. Fog droplet deposition was measured with eddy correlation and samples of fog water were taken with a string collector. At the same time, throughfall deposition was measured and throughfall water was sampled. The occult (fog/cloud) deposition during these periods was 3.4 and 2.0 mg m(-2) s(-1), respectively Throughfall fluxes measured during these periods were a factor of three higher. The contribution of occult deposition to the total acid deposition to forests in The Netherlands is estimated to be about 5%. A clear relationship between the friction veracity u(*) and turbulent deposition velocity v(t) of fog droplets could be derived. The measured turbulent deposition-velocity for fog is half the deposition velocity for impulse v(m). Copyright (C) 1996 Elsevier Science Ltd (Less)

Deposition of aerosol on speulder forest: Accumulation experiments

The deposition of alkaline and acidic aerosol compounds on a Douglas fir forest was measured by washing natural and artificial branches and using a certain type of Petri-dish sampler. The results were scaled to deposition on the entire canopy, using data on the vertical distribution of the leaf area index and the wind velocity profile within the canopy. The results are, within the uncertainty range of the measurements, comparable to those of net throughfall measurements corrected for canopy exchange, except for the results concerning Na and Cl. The calculated deposition velocities are high because of the high LAI and the large fraction of alkaline elements within the coarse-aerosol fraction. Theoretical data on aerosol deposition velocity compare well with the experimentally obtained values.

Particle deposition to forests.

Abstract Particle deposition to forest was studied using experimental and modelling results. Results show that the deposition of particles to forests has been underestimated until now. Particle deposition makes out reasonable contribution to the total deposition of acidifying components and base cations to forests. It was estimated that at Speulder forest the contribution of dry particle deposition to the total deposition was 18% for SO 4 , 38% for NO 3 , 23% for NH 4 , 56% for Na, 47% for K, 69% for Ca and 65% for Mg.. Deposition of compounds via fog at the Speulder forest was estimated to be small (

Crying Without Tears: Dimensions of Crying and Relations With Ocular Dryness and Mental Well-Being in Patients With Sjögren’s Syndrome

This study examined dimensions of crying and its relations with ocular dryness and mental well-being in patients with Sjögren’s syndrome, a systemic autoimmune disease with dryness as primary symptom. Three-hundred patients with Sjögren’s syndrome completed questionnaires on crying, dryness, and well-being. The crying questionnaire revealed four dimensions: “Cryability” (comprising both crying sensibility and ability to cry), Somatic consequences, Frustration, and Suppression. Compared to 100 demographically-matched control participants from the general population, patients scored low on Cryability and high on Somatic consequences and Frustration. The crying dimensions generally showed significant but weak associations with ocular dryness and mental well-being in patients. This is the first quantitative study indicating that crying problems are more common in patients with Sjögren’s syndrome than in the general population. Perhaps, patients who experience problems with crying could be helped to rely on other ways of expressing emotions than crying in tear-inducing situations.

THU0471-HPR Crying without tears: Dimensions of crying and relations with ocular dryness in patients with sjÖgren’s syndrome

Background When Henrik Sjögren described Sjögren’s syndrome (SS) for the first time in 1933, patients reported that their eyes stayed dry during crying, although they knew for sure that they were able to cry with tears before [1]. In the years thereafter, Sjögren’s syndrome has been firmly established as a disease, but only few studies mentioned problems with crying in this group, and not one study examined crying in patients with ocular dryness. Objectives To investigate the dimensions of crying and its relations to ocular dryness in patients with Sjögren’s syndrome, and to compare crying ability between patients and demographically-matched people from the general population. Methods Questionnaires were completed by 300 patients with SS and 100 demographically- matched people from the general population (93% female, mean age 56 years). Crying was investigated with the newly developed Sicca Crying Inventory (SCI), measuring multiple aspects of crying. Ocular dryness was measured with a 100mm Visual analogue scale (VAS). Principal axis factoring with oblimin rotation was used to derive the dimensions of the SCI, analyses of variance with posthoc Bonferonni comparisons were used to examine group differences, and partial correlation coefficients (corrected for age and gender) were used to examine correlations between the domains of crying dimensions and ocular dryness. Results The Sicca Crying Inventory consisted of four dimensions that were named crying ability (the capability to cry with tears, 7 items, α=0.93), frustration (suffering from the reduced ability to cry, 4 items, α=0.80), physical consequences (bodily symptoms like a burning sensation in the eyes, 4 items, α=0.77), and suppression (restrain tears or emotions, 2 items, α=0.85). Problems with crying ability were reported by 74% of the SS patients and by 46% of the control subjects. Scores of SS patients were lower on crying ability (p<0.001, d= -0.64) and higher on frustration (p<0.001, d=0.33) and physical consequences (p<0.05, d= -0.27) than scores of control subjects. The groups did not significantly differ in suppression. In SS, ocular dryness was correlated with a lower crying ability (r= -0.26, p<0.001) and more frustration (r=0.19, p=0.001) and physical consequences (r=0.22, p=0.001), but not significantly with suppression. Conclusions A large number of patients with Sjögren’s syndrome, but also relatively many people in the general population, reported crying problems, such as a reduced ability to cry with tears, frustration of the reduced ability to cry with tears, and physical consequences of crying. Crying problems correlated to some extent with ocular dryness. Apparently, inflammation of the tear glands is only one of many risk factors for crying problems. Crying is believed to be a strong form of human emotional expression. Patients who cannot use tears to process and express emotions may experience adjustment problems in tear-inducing situations. This study is a first step towards a better understanding of the observation of Henrik Sjögren eighty years ago. Supported by the Dutch Arthritis Association. References Sjögren H. Zur kenntnis der keratoconjunctivitis sicca: Keratitis filiformis bei hypofunktion der tränendrüsen. Acta Ophthalmol Suppl. 1933;2:1-151. Disclosure of Interest None Declared

FRI0297 The burden of dryness. a comprehensive overview from the perspective of patients with sjögren’s syndrome

Background The chronic autoimmune disease Sjögren’s syndrome is characterized by infiltration of the exocrine glands. The resulting dryness of eyes, mouth, and other parts of the body may have serious consequences for daily life functioning and well-being. Although dryness is the key feature of Sjögren’s syndrome, its consequences of dryness for daily life have not been systematically studied. Objectives Aim of this study was to identify a comprehensive overview of the consequences of dryness as perceived by patients with Sjögren’s syndrome. Methods Interviews were held with ten patients to yield statements about the consequences of dryness of patients with Sjögren’s syndrome. Thirty patients individually sorted the resulting 70 statements according to similarity. Hierarchical cluster analysis was used to structure the consequences of dryness. Results The hierarchical structure of dryness showed a higher-order distinction between statements reflecting ‘Generic’ and ‘Disease specific’ consequences (Figure). The lowest level consisted of 9 clusters. The “Quality of life” cluster included general consequences for quality of life that are also observed in other diseases. The cluster “Disease-specific” was subdivided into 1) consequences reflecting primary symptoms in the “Eyes” and “Mouth”, 2) burden of the disease such as “Participation” in social activities, “Somatic” problems involving the whole body, and problems with “Intimacy”, and 3) miscellaneous consequences such as “Sensitivity”, “Dry hair”, and use of “Aids” to deal with consequences of dryness. Image/graph Conclusions This study is the first to identify and structure consequences of dryness from the perspective of patients with Sjögren’s syndrome. The overview can be used as an assessment instrument to get a quick impression of consequences of dryness that are important for an individual patient. Moreover, the overview can be applied in therapeutic goal setting, in the development of a questionnaire, in the construction of interventions aimed to relieve the burden of dryness, and in the evaluation of medical and non-medical interventions or education. Acknowledgements Funded by: National Association Sjögren Patients, Dutch Arthritis Association. Disclosure of Interest: None Declared

THU0477-HPR Fatigue in psychosocial subgroups of patients with sjÖgren’s syndrome

Background Fatigue is a prevalent and debilitating problem in the systemic autoimmune disorder Sjögren’s syndrome. Psychosocial factors have been indicated to at least partly explain fatigue in this patient group. Insight into these factors and the relation of these factors with fatigue, will indicate the need for tailoring psychological interventions aimed at the reduction of fatigue to individual patients. Objectives To identify psychosocial subgroups of patients with Sjögren’s syndrome and to examine differences in fatigue between these subgroups. Methods 300 patients with primary Sjögren’s syndrome (mean age 56 years, 93% female) completed questionnaires on fatigue (MFI), physical activity cognitions (TAMPA-SK), illness cognitions (ICQ), cognitive emotion regulation (CERQ-short), coping strategies (Brief COPE), emotion processing and regulation (TAS-20, ERQ, BEQ), and social support (SSL, ABO). The psychosocial variables were summarized using principal axis factor analysis with oblimin rotation. Psychosocial subgroups were identified using hierarchical cluster analysis (Ward’s method) and K-means cluster analysis. Subgroup differences in fatigue were examined with univariate analysis of variance. Results Factor analysis yielded eight psychosocial factors: kinesiophobia (KP, fear to exercise), negative thinking (NT), positive thinking (PT), positive disease outcome (PD), alexithymia (AT), emotional expressivity (EE), social support (SS), and spouse engagement (SE). Cluster analyses identified four psychosocial subgroups: 1) an adaptive profile (n=64) with positive scores on all dimensions; 2) a self-reliance profile (n=64), with neutral scores on all dimensions except adaptive scores on positive thinking and positive disease outcomes and maladaptive scores on spouse engagement; 3) a maladaptive profile (n=52), with negative scores on all dimensions except a neutral score on emotional expressivity; and 4) a cognitive reappraisal profile, with adaptive scores on cognitive factors and maladaptive scores on emotional factors. Subgroup 3 reported more fatigue than the other subgroups on four of five fatigue dimensions (p<0.05), except physical fatigue compared to subgroup 2. The other subgroups did not differ from each other, with the exception of subgroup 2 reporting more mental fatigue, i.e. concentration and thought problems, than subgroup 4 (p<0.05). Conclusions Patients with Sjögren’s syndrome with a generalized maladaptive psychosocial profile experience more fatigue than patients with an adaptive, self-reliance or cognitive reappraisal profile. Thus, besides the identification of a single group with a generalized maladaptive profile, there is little support for tailoring fatigue interventions on the basis of psychosocial risk profiles. Supported by the Dutch Arthritis Association. Disclosure of Interest None Declared