bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of mineral and organic components in phenanthrene and dibenzofuran sorption by soil
Authors: Celis R. , De Jonge H. , De Jonge L. W. , Real M. , Hermosín M. C. , Cornejo J.
Published: September 2005

Improved predictions of sorption of hydrophobic organic compounds (HOCs) in soil require a better knowledge of the relative contribution of inorganic and organic soil constituents to the sorption process. In this paper, sorption of a three‐ring polycyclic aromatic hydrocarbon (phenanthrene) and a three‐ring heterocyclic–aromatic compound (dibenzofuran) by six agricultural soils, their clay‐size fractions, and a series of single, binary, and ternary model sorbents was evaluated to elucidate the relative role of soil mineral and organic components in the retention of these two model HOCs. The sorption coefficients for phenanthrene and dibenzofuran on purified soil organic materials (Kd = 821–9080 litre kg−1) were two orders of magnitude greater than those measured on mineral model sorbents (Kd = 0–114 litre kg−1). This, along with the strong correlation between sorption and the organic C content of the soil clay fractions (r = 0.99,P< 0.01), indicated a primary role of soil organic matter in the retention of both compounds. However, weak relationships between phenanthrene and dibenzofuran sorption coefficients and the organic C content of the bulk soils and variability ofKocvalues among soils, clay fractions, and model sorbents (1340–21020 litre kg−1C for phenanthrene and 1685–7620 litre kg−1C for dibenzofuran) showed that sorption was not predictable exclusively from the organic C content of the materials. Organic matter heterogeneity and domain blockage arising from organic matter–clay interactions and associated pH shifts were identified as the most likely causes of the different organic C‐normalized sorption capacities of the soils. A direct contribution from minerals to the sorption of phenanthrene and dibenzofuran by the soils studied was likely to be small. Our results suggested that suitable descriptors for the extent of organic matter–mineral interactions would help to improve currentKoc‐based sorption predictions and subsequently the assessment of risk associated with the presence of HOCs in soil.
Sorption regulates the fate of the amino acids lysine and leucine in soil aggregates
Authors: Vieublé Gonod L. , Jones D. L. , Chenu C.
Published: September 2005

Amino acids are substrates widely present in soils either in a free or a polymeric state and represent a large input of organic nitrogen into most terrestrial ecosystems. However, their behaviour in soil remains poorly understood. The aim of this study was to assess critically the impact of sorption on the mineralization of two contrastingly charged amino acids, lysine and leucine, in different‐sized, real soil aggregates. In a first experiment, we assessed the spatial variability of amino acid mineralization in aggregates of different sizes. After 1 day of incubation coefficients of variation of leucine mineralization were 33% in aggregates of 2–3 mm, 15% in aggregates of 3–5 mm and 14% in aggregates of 5–7 mm diameter. Coefficients of variation of lysine mineralization were, after 1 day of incubation, 24% in aggregates of 2–3 mm, 26% in aggregates of 3–5 mm and 24% in aggregates of 5–7 mm diameter. Compared with other substrates, this variability is small and could be due to the presence of degrading microorganisms in all aggregates. We also studied the activity of such microorganisms by following the evolution with time of 14C‐amino acids in different compartments within aggregates 3–5 mm diameter (mineralized 14C, microbial biomass 14C, 14C in soil solution and residual 14C in soil). The microorganisms that degrade amino acids were able to assimilate substrates in soil solution immediately and used them preferentially for their growth and not solely for their energy production. For lysine, intense competition between adsorption and assimilation by microorganisms occurred from the start of the incubation period and persisted with time. Our results clearly show that sorption may retard biodegradation of amino acids in soil.
Monitoring organic matter dynamics in soil profiles by ‘Rock‐Eval pyrolysis’: bulk characterization and quantification of degradation
Authors: Sebag D. , Disnar J. R. , Guillet B. , Di Giovanni C. , Verrecchia E. P. , Durand A.
Published: September 2005

Rock‐Eval pyrolysis was designed for petroleum exploration to determine the type and quality of organic matter in rock samples. Nevertheless, this technique can be used for bulk characterization of the immature organic matter in soil samples and recent sediments. We studied 76 samples from seven soil classes and showed that their pyrograms can be described by a combination of four elementary Gaussian components: F1, F2, F3 and F4. These four components are related to major classes of organic constituents differing in origin and their resistance to pyrolysis: labile biological constituents (F1), resistant biological constituents (F2), immature non‐biotic constituents (F3) and a mature refractory fraction (F4). We discriminated the relative contributions of these components and used them to derive two indices: (i) to quantify the relative contributions of labile and resistant biological constituents and (ii) to quantify the degradation stage of the soil organic matter. The practical applications are illustrated via the influence of vegetal cover on soil organic matter dynamics and peat development in a Holocene sedimentary sequence, but we suggest that the approach is of much wider application.
Evolution of water‐extractable copper in soil with time as a function of organic matter amendments and aeration
Authors: Wang G. , Staunton S.
Published: September 2005

Variations in soil conditions can influence the speciation and hence availability of copper. We have followed the evolution of water‐extractability of both native and added copper in a clay‐loam topsoil over 5 months. The effects of addition of organic amendments, either leaf compost or lucerne straw, were studied. Soils were incubated under controlled conditions either moist and well‐aerated, or flooded. Other chemical properties were monitored (pH, redox potential, water‐extractable organic carbon, iron and manganese). Freshly added Cu was initially more soluble than native Cu, but the contrast decreased with time. Solubility was greater in flooded soils than in aerated samples. Solubility also increased with increasing pH, contrary to often‐reported trends. Although the extractability of added Cu increased with increasing dissolved organic carbon, as expected from the formation of complexes in solution, that of native soil Cu did not. Large, short‐lived flushes of Cu were associated with flushes of dissolved organic matter, particularly from decomposition of lucerne straw, but these relations were not always statistically significant when the entire data set was considered. The total amount of dissolved organic carbon is not a sufficiently sensitive probe to assess the extent to which Cu is solubilized by the formation of complexes in soil solution. The changing composition of soil and soil solution during incubation led to 10‐fold differences in the proportion of Cu that was water‐extractable. Single measurements of extractability can therefore never give an accurate estimation of mobility and availability of copper in soil.
Total and soluble fluorine concentrations in relation to properties of soils in New Zealand
Authors: Loganathan P. , Gray C. W. , Hedley M. J. , Roberts A. H. C.
Published: September 2005

Soil fluorine (F) concentrations continue to increase in agricultural soils receiving regular applications of phosphatic fertilizer. Continued accumulation of soil F poses a risk to grazing ruminants and may pose a future risk to groundwater quality. This paper examines the range of total F (Ft) concentrations and forms of soluble F species and their relationship to selected soil properties in New Zealand agricultural soils. The Ftand soluble F (soil F extracted with water (Fwater) and 0.01 mKCl (FKCl)) concentrations in 27 soil samples (0–75 mm depth) taken from predominantly pasture sites in the North and South Islands of New Zealand were much less than those reported in the literature for sites contaminated with F from industry. The Ftconcentrations ranged from 212 to 617 µg F g−1soil. The F‐toxicity risk to grazing animals in farms at these sites through soil ingestion is small at present, but farms with very large Ftconcentrations (i.e. > 500 µg F g−1) need to adopt suitable grazing and fertilizer management practices to avoid future F‐toxicity risk. The Ftconcentration had very strong positive correlations with both total soil P and total soil Cd concentrations, reflecting the link between P fertilizer use and F accumulation in the soils. It also had significant positive correlations with organic matter and amorphous Al oxides contents, indicating that F is strongly bound to Al polymers adsorbed to organic matter and amorphous Al oxides. The Fwaterand FKClconcentrations and free F–ion concentrations in water (F–water) and 0.01 mKCl (F–KCl) extracts were generally two and three orders of magnitude, respectively, less than the Ftconcentrations and were much less than the concentrations considered phytotoxic. The Fwaterand FKClconcentrations were positively related to soil organic matter content and negatively related to soil pH. Regression models relating Fwaterand FKClconcentrations to soil organic matter content and soil pH suggest that F can be very soluble in extremely acidic soils (pH(water) < 4.9) with large organic matter contents and therefore F potentially may contaminate groundwater if these soils are also coarse‐textured and the water table is shallow.
Estimating the contribution of leaf litter decomposition to soil CO2efflux in a beech forest using13C‐depleted litter
Authors: Ngao Jérôme , Epron Daniel , Brechet Claude , Granier André
Published: September 2005

The contribution of leaf litter decomposition to total soil CO2efflux (FL/F) was evaluated in a beech (Fagus sylvaticaL.) forest in eastern France. The Keeling‐plot approach was applied to estimate the isotopic composition of respired soil CO2from soil covered with either control (−30.32‰) or13C‐depleted leaf litter (−49.96‰). Theδ13C of respired soil CO2ranged from −25.50‰ to −22.60‰ and from −24.95‰ to −20.77‰, respectively, with depleted or control litter above the soil. TheFL/Fratio was calculated by a single isotope linear mixing model based on mass conservation equations. It showed seasonal variations, increasing from 2.8% in early spring to about 11.4% in mid summer, and decreasing to 4.2% just after leaf fall. Between December 2001 and December 2002, cumulatedFandFLreached 0.98 and 0.08 kgC m−2, respectively. On an annual basis, decomposition of fresh leaf litter accounted for 8% of soil respiration and 80% of total C loss from fresh leaf litter. The other fraction of carbon loss during leaf litter decomposition that is assumed to have entered the soil organic matter pool (i.e. 20%) represents only 0.02 kgC m−2.
Alterations in the production and concentration of selected alkaloids as a function of rising atmospheric carbon dioxide and air temperature: implications for ethno‐pharmacology
Authors: Ziska L. H. , Emche S. D. , Johnson E. L. , George K. , Reed D. R. , Sicher R. C.
Published: September 2005

The influence of recent and projected changes in atmospheric carbon dioxide concentration [CO2] with and without concurrent increases in air temperature was determined with respect to growth characteristics and production of secondary compounds (alkaloids) in tobacco (Nicotiana tabacum L.) and jimson weed (Datura stramonium L.) over a ca. 50‐day period. Rising [CO2] above that present at the beginning of the 20th century resulted in consistent, significant increases in leaf area, and above ground dry weight (both species), but decreased leaf area ratio (LAR) and specific leaf area (SLA) in jimson weed. Increased temperature resulted in earlier development and increased leaf area for both species, but increases in above ground final dry weight were observed only for jimson weed. The secondary compounds evaluated included the alkaloids, nicotine, atropine and scopolamine. These compounds are generally recognized as having impacts with respect to herbivory as well as human physiology. Rising [CO2] reduced the concentration of nicotine in tobacco; but had no effect on atropine, and increased the concentration of scopolamine in jimson weed. However, because of the stimulatory effect of [CO2] on growth, the amount of all three secondary compounds increased on a per plant basis in both species. Temperature per se had no effect on nicotine or scopolamine concentration, but significantly increased the concentration and amounts of atropine per plant. Overall, the underlying mechanism of CO2 induced changes in secondary compounds remains unclear; however, these data suggest that the increase in [CO2] and temperature associated with global climate change may have significant effects not only with respect to herbivory, but on the production of secondary compounds of pharmacological impact.
Impacts of an anomalously warm year on soil CO2 efflux in experimentally manipulated tallgrass prairie ecosystems
Authors: Verburg Paul S. J. , Larsen Jessica , Johnson Dale W. , Schorran David E. , Arnone John A.
Published: September 2005

Modeling analyses suggest that an increase in growth rate of atmospheric CO2 concentrations during an anomalously warm year may be caused by a decrease in net ecosystem production (NEP) in response to increased heterotrophic respiration (Rh). To test this hypothesis, 12 intact soil monoliths were excavated from a tallgrass prairie site near Purcell, Oklahoma, USA and divided among four large dynamic flux chambers (Ecologically Controlled Enclosed Lysimeter Laboratories (EcoCELLs)). During the first year, all four EcoCELLs were subjected to Oklahoma air temperatures. During the second year, air temperature in two EcoCELLs was increased by 4°C throughout the year to simulate anomalously warm conditions. This paper reports on the effect of warming on soil CO2 efflux, representing the sum of autotrophic respiration (Ra) and Rh.

During the pretreatment year, weekly average soil CO2 efflux was similar in all EcoCELLs. During the late spring, summer and early fall of the treatment year, however, soil CO2 efflux was significantly lower in the warmed EcoCELLs. In general, soil CO2 efflux was correlated with soil temperature and to a lesser extent with moisture. A combined temperature and moisture regression explained 64% of the observed variation in soil CO2 efflux. Soil CO2 efflux correlated well with a net primary production (NPP) weighted greenness index derived from digital photographs. Although separate relationships for control and warmed EcoCELLs showed better correlations, one single relationship explained close to 70% of the variation in soil CO2 efflux across treatments and years. A strong correlation between soil CO2 efflux and canopy development and the lack of initial response to warming indicate that soil CO2 efflux is dominated by Ra. This study showed that a decrease in soil CO2 efflux in response to a warm year was most likely dominated by a decrease in Ra instead of an increase in Rh.
Estimating annual N2O emissions from agricultural soils in temperate climates
Authors: Roelandt Caroline , Van Wesemael Bas , Rounsevell Mark
Published: September 2005

The Kyoto protocol requires countries to provide national inventories for a list of greenhouse gases including N2O. A standard methodology proposed by the Intergovernmental Panel on Climate Change (IPCC) estimates direct N2O emissions from soils as a constant fraction (1.25%) of the nitrogen input. This approach is insensitive to environmental variability. A more dynamic approach is needed to establish reliable N2O emission inventories and to propose efficient mitigation strategies. The objective of this paper is to develop a model that allows the spatial and temporal variation in environmental conditions to be taken into account in national inventories of direct N2O emissions. Observed annual N2O emission rates are used to establish statistical relationships between N2O emissions, seasonal climate and nitrogen‐fertilization rate. Two empirical models, MCROPS and MGRASS, were developed for croplands and grasslands. Validated with an independent data set, MCROPS shows that spring temperature and summer precipitation explain 35% of the variance in annual N2O emissions from croplands. In MGRASS, nitrogen‐fertilization rate and winter temperature explain 48% of the variance in annual N2O emissions from grasslands. Using long‐term climate observations (1900–2000), the sensitivity of the models with climate variability is estimated by comparing the year‐to‐year prediction of the model to the precision obtained during the validation process. MCROPS is able to capture interannual variability of N2O emissions from croplands. However, grassland emissions show very small interannual variations, which are too small to be detectable by MGRASS. MCROPS and MGRASS improve the statistical reliability of direct N2O emissions compared with the IPCC default methodology. Furthermore, the models can be used to estimate the effects of interannual variation in climate, climate change on direct N2O emissions from soils at the regional scale.
Calcium release and pH‐characteristics of calcium hydroxide plus points
Authors: Lohbauer U. , Gambarini G. , Ebert J. , Dasch W. , Petschelt A.
Published: September 2005

Aim  To evaluate calcium ion release and pH‐characteristics of calcium hydroxide plus points (CHPP), conventional calcium hydroxide points (CHP, both Coltène/Whaledent, Langenau, Germany) and aqueous calcium hydroxide suspension (CHS) (Calxyl, OCO, Dirmstein, Germany).

Methodology  Ten CHPP or CHP of size 50 were immersed into 5 mL isotonic sodium chloride solution. Conventional Ca(OH)2‐free gutta‐percha points served as negative control. Calcium release was measured up to 44 days by means of complexometric titration. Time dependent pH behaviour of all points in comparison with CHS was determined immersing 30 points of size 50 into 2.3 mL 0.9% wt NaCl‐solution at time intervals of 0.5–72 h by a microelectrode measuring chain and a pH‐meter. The surface morphologies of new and used gutta‐percha points were evaluated qualitatively under a scanning electron microscope. Statistical evaluation was carried out using Kolmogorov–Smirnov‐tests, Mann–Whitney‐tests and multifactorial anova.

Results  For CHPP, a threefold greater calcium release was measured compared with CHP. Both types of points as well as CHS showed a maximum pH of approximately 12. Differences between groups were statistically significant for calcium release and pH (multifactorial anova; P < 0.001). Both types of points showed porous surfaces after usage, with a rougher surface for CHPP.

Conclusions  CHPP and CHP increased the pH of isotonic sodium chloride >11 within 3 min. CHPP had a greater release of Ca2+ compared with CHP.
Presence of pores and vacuoles in set endodontic sealers
Authors: Mutal L. , Gani O.
Published: September 2005

Aim  To assess qualitatively the presence of pores and vacuoles in the structure of various endodontic sealers when set.

Methodology  Eight specimens were prepared in keeping with Instituto Argentino de Racionalización de Materiales (IRAM) and ISO regulations for each of the 10 sealers assessed. Four specimens per sealer were examined to identify the presence of structural defects, termed pores, on the external surface. The remaining four specimens were used to examine the presence of defects on the surface exposed by cross‐sectional fracture; these were termed vacuoles. The largest and smallest diameters of the pores and vacuoles were measured by scanning electron microscope on both surfaces. The structural defects were classified according to their frequency as abundant, frequent, scarce or exceptional.

Results  Pores and vacuoles were consistently found in every specimen of each sealer. However, their frequency and dimensions were greater in zinc‐eugenol‐based sealers than in epoxy‐resins and glass–ionomer sealers; they increased if the sealer contained calcium hydroxide. The diameter of the pores ranged from 5 to 320 μm and the diameter of the vacuoles ranged from 80 to 500 μm. The diameter of the vacuoles always exceeded that of the pores.

Conclusions  Pores and vacuoles were a consistent finding in set sealers. Their frequency and size depended on the density of the sealer and increased when the sealers contained calcium hydroxide.
Temperature rise of the post and on the root surface during ultrasonic post removal
Authors: Budd J. C. , Gekelman D. , White J. M.
Published: September 2005

Aim  To determine the temperature rise on the root surface caused by ultrasonic post removal using different devices and techniques in a laboratory setting.

Methodology  Two ultrasonic devices, one piezoelectrical (Pi) and one magnetostrictive (Ma), were investigated. A serrated titanium post was placed into the distal root canal of a human mandibular first molar. Four coolant parameters were utilized: no air, no water, no evacuation (NN), air only with high‐speed evacuation (A), 15 mL min−1 water coolant with high‐speed evacuation (W15) and 30 mL min−1 water coolant with high‐speed evacuation (W30). Five simulated post removals were measured at two locations, the post (P) and the root (R), for each coolant parameter. Temperature rise was measured at 30, 60, 90 and 120 s intervals using calibrated infrared thermography (n = 80). Temperatures were recorded at 45 ms intervals. Data were analysed using repeated measures anova with the Scheffe post hoc test (P ≤ 0.05).

Results  The overall mean pooled effect showed that temperature rise for P = 20.1 ± 27.9 °C and R = 10.9 ± 7.9 °C were significantly different. Significant differences in temperature rise were: Pi > Ma, P > R, NN > A = W15 = W30 however, A > W30.

Conclusions  There were significant differences in temperature rise as a function of ultrasonic device, location on the tooth and cooling method utilized for post removal.
Calcitonin gene‐related peptide receptor expression in healthy and inflamed human pulp tissue
Authors: Caviedes‐Bucheli J. , Arenas N. , Guiza O. , Moncada N. A. , Moreno G. C. , Diaz E. , Munoz H. R.
Published: September 2005

Aim  To use radioreceptor analysis for comparing calcitonin gene‐related peptide (CGRP) receptor expression in human pulp tissue samples collected from teeth having a clinical diagnosis of acute irreversible pulpitis, healthy pulps and teeth with induced inflammation.

Methodology  Six pulp samples were obtained from teeth having a clinical diagnosis of acute irreversible pulpitis. Another eight pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic purposes. In four of these premolars, inflammation was induced prior to pulp collection. All the samples were processed and labelled with 125I‐CGRP. Binding sites were identified by 125I‐CGRP and standard CGRP competition assays.

Results  CGRP receptor expression was found in all human pulp tissue samples. Most receptors were found in the group of pulps from teeth having a clinical diagnosis of acute irreversible pulpitis, followed by the group of pulps having induced inflammation. The least number of receptors was expressed in the group of healthy pulps. The Kruskal–Wallis and Mann–Whitney (post‐hoc) tests showed statistically significant differences between the groups (P < 0.05).

Conclusion  CGRP receptor expression in human pulp tissue is significantly increased during inflammatory phenomena such as acute irreversible pulpitis.
Technical quality of root canal treatment and detection of iatrogenic errors in an undergraduate dental clinic
Authors: Eleftheriadis G. I. , Lambrianidis T. P.
Published: September 2005

Aim  To evaluate the technical quality of root canal treatment (RCT) and detect iatrogenic errors in an undergraduate dental clinic.

Methodology  Three‐hundred and eighty‐eight root‐filled teeth from the records of the Department of Endodontology at the Aristotle University of Thessaloniki, Greece were evaluated. Evaluation of root‐filled teeth was based on two variables: length and presence of voids within the root filling. The technical standard of root fillings was categorized as: ≤2 mm from the apex with no voids (acceptable); >2 mm from the apex with no voids; overfilling with no voids; ≤2 mm from the apex with voids; >2 mm from the apex with voids and overfilling with voids. Iatrogenic errors that were detected included ledges, root perforations, furcation perforations, strip perforations and presence of fractured instruments. Chi‐squared analysis was used to determine statistically significant differences between frequencies of root fillings between each tooth type. Significant differences were also determined between frequencies of ledges and root perforations according to tooth type and separately in molars according to tooth number, canal location and root canal curvature.

Results  Three‐hundred and forty‐three out of 620 root canals (55.3%) had a root filling that was classified as ‘acceptable’. The frequency of root canals with an ‘acceptable’ filling was significantly greater in the anterior teeth (72.1%) than in pre‐molars (55.2%) (P < 005) or in molars (46.7%) (P < 0.001). One‐hundred and fifty‐four (24.8%) root canals had ledges and 17 (2.7%) had a root perforation. The frequency of ledged root canals was significantly greater (P < 0.001) in molars than in anterior teeth. In molars, 105 out of 270 root canals (38.9%) had been ledged. Mesiobuccal, mesiolingual and distobuccal root canals were the most frequently ledged. Canal curvature was found to be the most important factor associated with ledges and root perforations.

Conclusions  Technical quality was found to be acceptable more often in anterior teeth. Ledges were identified more often in curved canals in molar teeth.
The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from human root canals prepared using instruments of varying taper
Authors: Van Der Sluis L. W. M. , Wu M‐K. , Wesselink P. R.
Published: September 2005

Aim  To investigate the influence of the taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris.

Method  Forty‐four maxillary and mandibular canines were selected after bucco‐lingual and mesio‐distal radiographs indicated that their internal diameters were smaller than the diameters of a size 20, .06 taper System GT instrument (Dentsply Maillefer, Ballaigues, Switzerland). These canines were divided into three groups and prepared using either size 20, .06 taper System GT instruments, size 20, .08 taper or size 20, .10 taper System GT instruments. Each root was then split longitudinally through the canal, forming two halves. In one canal wall, a standard groove was cut 2–6 mm from the apex, to simulate uninstrumented canal extensions. Each groove was filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in the uninstrumented canal extensions. Each canal was reassembled by joining the two halves of the teeth by means of wires and sticky wax. In each canal ultrasonic irrigation was performed with a size 15 K file using 2% NaOCl as an irrigant. Before and after irrigation, images of each half of the canal with a groove were taken using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris. The scores before and after irrigation were compared. The differences in percentage of score reduction between the three groups were analysed by means of one‐way anova.

Results  After ultrasonic irrigation, the debris score reduced by 74, 81 and 93%, respectively, in the size 20, .06, 20, .08 and 20, .10 taper groups. However, the difference amongst groups was not statistically significant (P = 0.078).

Conclusion  There was a tendency that ultrasonic irrigation was more effective in removing artificially placed dentine debris from simulated canal extensions from canals with greater tapers.
Quality of care: the need for medical, contextual and policy evidence in primary care
Authors: Van Driel Mieke L. , De Sutter An I. , Christiaens Thierry C. M. , De Maeseneer Jan M.
Published: September 2005

The increasing availability of medical evidence in clinical practice was expected to improve the quality of care. However, this has not been realized. A possible explanation is that quality of care is a complex concept and needs a wider scope. Starting from the Donabedian triangle of structure, process and outcome, a framework for the analysis of quality of care is presented. The need for three types of evidence is identified and discussed: medical, contextual and policy evidence. Although the body of medical evidence is increasing, it has major flaws and gaps hampering its applicability in primary care. There is also a need to focus on the context of the medical encounter, which has been shown to influence outcome, but is still not well researched. Finally, evidence on costs, cost utility and equity needs to be considered. Taking these different aspects of evidence into account, an agenda for research in primary care is set. The analytical framework may provide new insights in the quest for improving quality of health care.
Differences between nurse and patient assessments on postoperative pain management in two hospitals
Authors: Idvall Ewa , Berg Katarina , Unosson Mitra , Brudin Lars
Published: September 2005

Rationale  Differences between patient and professional assessments on pain and pain management have been reported, but no further analysis has described the statistical problems of pseudocorrelation concerning the nature of these differences.

Aim  The aim of the present study was: (1) to investigate the differences between nurse and patient assessments of postoperative pain management in two hospitals, and (2) to discuss the nature and  scope  of  these  differences.

Method  The subjects were 209 inpatients and 63 nurses from a central county hospital and 77 inpatients and 34 nurses from a university hospital. The ‘Strategic and Clinical Quality Indicators in Postoperative Pain Management’ questionnaire was used, comprising 14 items in four sub‐scales (communication, action, trust and environment) and two questions concerning the worst pain experienced during the past 24 hours and general satisfaction.

Result  Except for the trust sub‐scale in one hospital, the correlations between patient and nurse ratings concerning all assessments were significant in both hospitals (r = 0.22 − 0.59). Both groups of patients had significantly higher (better) scores than judged by the nurses on the environment sub‐scale and general satisfaction. In contrast, nurses from both hospitals tended to significantly underestimate patients’ worst pain during the past 24 hours. Other differences between patient and nurse assessments were either non‐significant or inconsistent between hospitals. Using so‐called Oldham plots nurses tended to underestimate severe pain more often than mild pain, as judged by the patients, but this association was weak and statistically significant in one hospital only.

Conclusion  Although the effects of pseudocorrelation are minimized by using Oldham plots, they are not cancelled. This issue is discussed, and we conclude that this study does not support the notion that the nurses tend to underestimate severe pain more often than mild pain.
An overview of methods and empirical comparison of aggregate data and individual patient data results for investigating heterogeneity in meta‐analysis of time‐to‐event outcomes
Authors: Smith Catrin Tudur , Williamson Paula R. , Marson Anthony G.
Published: September 2005

Combining the results of individual studies using meta‐analysis may be undertaken using either aggregate data (AD) or individual patient data (IPD). In any meta‐analysis it is important to consider statistical heterogeneity between studies. Potential sources of heterogeneity can be explored using regression models with either AD or IPD. An overview of approaches and empirical assessment of how the results and conclusions differ from these analyses is undertaken using a meta‐analysis of five randomized controlled trials comparing two antiepileptic drugs with time‐to‐event outcomes. Alternative meta‐regression models using AD are compared to stratified Cox regression models using IPD. Age as a potential cause of heterogeneity is detected by both AD and IPD regression models. Time from first ever seizure to randomization is only identified by some AD models. A more thorough explanation of heterogeneity is obtained from the model using IPD but further empirical evidence comparing IPD and AD results are needed.
New technology to enable personal monitoring and incident reporting can transform professional culture: the potential to favourably impact the future of health care
Authors: Bolsin Stephen , Patrick Andrew , Colson Mark , Creatie Bernie , Freestone Liadane
Published: September 2005

There have been recent exposures of poor health care performance in many countries with western health care systems. The poor performance has either related to poor or criminal practices routinely going undetected or to organizational indifference or hostility to staff raising concerns about perceived poor standards of care. The demonstration that routine performance data monitoring would have detected and prevented many of the deaths attributed to poor surgical standards in the Bristol Royal Infirmary paediatric cardiac surgery scandal and criminal behaviour in the Harold Shipman scandal has highlighted the need for routine data collection to demonstrate to both health care administrators and patients that minimum standards of clinical practice are being achieved. The recent proposal that surgical report cards represent an important minimum ethical standard for health care consent will force the medical profession to engage in the debate surrounding routine data collection for performance monitoring and other purposes. This article considers the cultural background to data collection in the medical profession and the cost implications of failing to improve data collection in the areas of performance monitoring and incident reporting. A potential solution developed by the Geelong hospital group and in use in Australia is proposed as a novel, technologically appropriate and working example of practical data collection. This model is endorsed by the professional specialties and supported by modern regulatory theory. The individual, local and system wide benefits of such personal professional data collection are outlined and the necessary prerequisites are detailed.
Cluster randomized controlled trials
Authors: Puffer Suezann , Torgerson David J. , Watson Judith
Published: September 2005

Cluster randomized controlled trial (RCT), in which groups or clusters of individuals rather than individuals themselves are randomized, are increasingly common. Indeed, for the evaluation of certain types of intervention (such as those used in health promotion and educational interventions) a cluster randomized trial is virtually the only valid approach. However, cluster trials are generally more difficult to design and execute than individually randomized studies, and some design features of a cluster trial may make it particularly vulnerable to a range of threats that can introduce bias. In this paper we discuss the issues that can lead to bias in cluster randomized trials and conclude with some suggestions for avoiding these problems.
Role development in health care assistants: the impact of education on practice
Authors: Hancock Helen , Campbell Steve , Ramprogus Vince , Kilgour Julie
Published: September 2005

Rationale  Health care provision has moved towards an approach to patient care that challenges the traditional role boundaries of health care workers. In nursing this has resulted in the delegation of ‘nursing care’ to health care assistants (HCAs). This study sought to evaluate the impact of a HCA Development Programme on care delivery. Secondly, it sought to understand the preparedness of HCAs to undertake the programme and the new roles set for  them.

Methodology  The research method was a qualitative, inductive approach. For part one, data were gathered using a 360‐degree approach. Semi‐structured interviews were conducted with four HCAs, eight of each of their colleagues and four patients. For part two, 12 HCAs were interviewed. Data were analysed following the principles of thematic analysis.

Findings  The findings for part one showed positive changes to the HCAs’ role, which included skill and knowledge development, increased confidence and initiative and a more holistic approach to care. A range of personal and contextual factors including relationships, hierarchy, staffing, experience, responsibility, patient dependency, attitudes and values affected the development of their role. The HCAs in part two voiced positive and negative views of their role development. Of the 12 HCAs interviewed, eight were prepared to attend the programme, two were undecided, and two  were  reluctant  to  attend.

Conclusions  The findings indicated that while the HCA Development Programme positively influenced the role of the HCA, there was a need to invest more into preparation for the restructuring of roles.
Detection of quinolone‐resistance genes in Photobacterium damselae subsp. piscicida strains by targeting‐induced local lesions in genomes
Authors: Kim M‐J , Hirono I , Aoki T
Published: September 2005

Quinolone‐resistant strains of the fish‐pathogenic bacterium, Photobacterium damselae subsp. piscicida are distributed widely in cultured yellowtail, Seriola quinqueradiata (Temminck & Schlegel), in Japan. The quinolone resistance‐determining region (QRDR) was amplified with degenerate primers, followed by cassette ligation‐mediated PCR. Open reading frames encoding proteins of 875 and 755 amino acid residues were detected in the gyrA and parC genes, respectively. Resistant strains of P. damselae subsp. piscicida carried a point mutation only in the gyrA QRDR leading to a Ser‐to‐Ile substitution at residue position 83. No amino acid alterations were discovered in the ParC sequence. A mutation in the gyrA gene was also detected in nalidixic acid‐resistant mutants of strain SP96002 obtained from agar medium containing increased levels of quinolone. These results suggest that GyrA, as in other Gram‐negative bacteria, is a target of quinolone in P. damselae subsp. piscicida. Furthermore, we attempted to detect a point mutation using targeting‐induced local lesions in genomes (TILLING), which is a general strategy used for the detection of a variety of induced point mutations and naturally occurring polymorphisms. We developed a new detection method for the rapid and large‐scale identification of quinolone‐resistant strains of P. damselae subsp. piscicida using TILLING.
Gross signs and histopathology of branchiostegal blister disease (balloon disease): an idiopathic disease of farmed Macrobrachium rosenbergii (De Man)
Authors: Pillai D , Nair C M , Salin K R , Marques A , Widada J S , Bonami J‐R
Published: September 2005

The giant freshwater prawn, Macrobrachium rosenbergii, is facing increased threat due to disease as its culture becomes more widespread. A disease characterized by the swelling of the branchiostegal region and deformities of the appendages, named balloon disease by farmers, has caused considerable economic loss in the Nellore region of Andhra Pradesh, India. Clinical signs of diseased animals include a voluminous hypertrophy of some gill filaments and the inner area of the branchiostegite. By histology, hypertrophied areas at the level of the gill filaments or branchiostegite had an identical structure corresponding to a large cyst filled with a fluid containing a few free haemocytes, limited on one side by the cuticle and on the other by the subcuticular epithelial layer. Analysis of the diseased prawns did not reveal any pathogenic agent leading us to conclude that the disease is idiopathic, probably due to suboptimal water quality conditions.
Descriptions, development and pathogenicity of myxozoan (Myxozoa: Myxosporea) parasites of juvenile cyprinids (Pisces: Cyprinidae)
Authors: Longshaw M , Frear P A , Feist S W
Published: September 2005

Approximately 5000 young of the year (0+) cyprinids comprising roach, chub, dace, minnow, bleak, bream, barbel and gudgeon were examined histologically for the presence of myxozoan infections. Thirteen myxozoans were identified to species, the majority being Myxobolus spp. In addition, two species of Myxidium and of Sphaerospora were recorded. All organs were examined, with the majority of infections being found in the gills, musculature and kidney. However, isolated spores were occasionally found in other tissues. Whilst roach contained the highest number of myxozoan species, it was chub that showed the greatest host response to sporogonic forms. Data are provided on spore morphology, pathogenic responses and tissue and host specificity of the myxozoans recorded.
Algorithms to estimate the rose of directions of a spatial fibre system
Authors: KIDERLEN M. , PFRANG A.
Published: September 2005

The directional measure (which is up to normalization the rose of directions) is used to quantify anisotropy of stationary fibre processes in three‐dimensional space. There exist a large number of approaches to estimate this measure from the rose of intersections (which is the mean number of intersections of fibres with lower dimensional test sets). Three recently suggested nonparametric algorithms to solve this problem are reviewed and compared. They were obtained from solutions of a least squares problem, a more general convex optimization problem and a linear program, respectively. Application to two different carbon fibre architectures and to simulated data allow an empirical comparison of these approaches. In addition, estimators for the associated zonoid (or Steiner compact) are suggested. This set turns out to be an intuitive tool for visualization.
A multiparametric assay for quantitative nerve regeneration evaluation
Authors: WEYN B. , VAN REMOORTERE M. , NUYDENS R. , MEERT T. , VAN DE WOUWER G.
Published: September 2005

We introduce an assay for the semi‐automated quantification of nerve regeneration by image analysis. Digital images of histological sections of regenerated nerves are recorded using an automated inverted microscope and merged into high‐resolution mosaic images representing the entire nerve. These are analysed by a dedicated image‐processing package that computes nerve‐specific features (e.g. nerve area, fibre count, myelinated area) and fibre‐specific features (area, perimeter, myelin sheet thickness). The assay's performance and correlation of the automatically computed data with visually obtained data are determined on a set of 140 semithin sections from the distal part of a rat tibial nerve from four different experimental treatment groups (control, sham, sutured, cut) taken at seven different time points after surgery. Results show a high correlation between the manually and automatically derived data, and a high discriminative power towards treatment. Extra value is added by the large feature set. In conclusion, the assay is fast and offers data that currently can be obtained only by a combination of laborious and time‐consuming tests.
Reconstruction of pore space from a pore connectivity network via morphological transformations
Authors: TEO L. L. , DAYA SAGAR B. S.
Published: September 2005

Pore and grain regions were separated via thresholding techniques from sandstone images. A mathematical morphology‐based framework was followed to pack the random pore space with overlapping and nonoverlapping disks. This framework has several advantages in implementation and is generally applicable to multiscale images. The random pore space was reconstructed in two ways from the minimum morphological information through: (a) overlapping and (b) nonoverlapping disks of various shapes and sizes. The structuring elements employed to carry out this analysis included octagon, square and rhombus templates. The results achieved through these two types of reconstruction of sandstone pores are compared. These results provided the basis on which to test the accuracy of these techniques. Reconstruction recovery was tested by computing shapiness indices for the reconstructed pores achieved through the two methods.
Non‐invasive assessment of motor unit anatomy in jaw‐elevator muscles
Authors: CASTROFLORIO T. , FARINA D. , BOTTIN A. , DEBERNARDI C. , BRACCO P. , MERLETTI R. , ANASTASI G. , BRAMANTI P.
Published: September 2005

summary The estimation of fibre length in jaw‐elevator muscles is important for modelling studies and clinical applications. The objective of this study was to identify, from multi‐channel surface EMG recordings, the main innervation zone(s) of the superficial masseter and anterior temporalis muscles, and to estimate the fibre length of these muscles. Surface EMG signals were collected from 13 subjects with a 16‐electrode linear array. The innervation zones of the masseter and anterior temporalis were identified and their variability intra‐ and inter‐subject outlined. More than one main innervation zone location was identified in the masseter of all subjects and in the temporalis anterior of 12 subjects. Average estimated fibre lengths, for the right (left) side, were (mean ± SD) 27·3 ± 2·4 mm (27·0 ± 1·7 mm) and 25·9 ± 2·3 mm (26·6 ± 1·6 mm), for the superficial masseter and temporalis anterior muscle, respectively. The range of innervation zone locations was up to approximately 50% of the fibre length, both within and between subjects. Fibre length estimates well matched with published data on cadavers. It was concluded that multi‐channel surface EMG provides important and reliable information on the anatomy of single motor units in jaw‐elevator muscles.
Retrospective survival analysis of 3‐unit fixed‐fixed and 2‐unit cantilevered fixed partial dentures
Authors: CHAI J. , CHU F. C. S. , NEWSOME P. R. H. , CHOW T. W.
Published: September 2005

summary To evaluate the cumulative survival (CS) rates of fixed partial dentures (FPDs) retained by full‐veneer retainers, and those of resin‐bonded FPDs provided by graduating dental students for the replacement of a single missing tooth. In 168 patients, 61 3‐unit fixed‐fixed FPDs and 25 2‐unit cantilevered FPDs retained by full‐veneer retainers, and 77 3‐unit fixed‐fixed resin‐bonded FPDs and 47 2‐unit cantilevered resin‐bonded FPDs, were examined for their retention and integrity. The periodontal health, endodontic status and coronal tissues of all abutment teeth were also evaluated. The survival rates of these various designs were analysed with the Kaplan–Meier method. The mean age of all FPDs was 31 months. At 48 months after their insertion, 3‐unit FPDs retained by full‐veneer retainers had a CS rate of 82%, followed by 2‐unit resin‐bonded FPDs at 81%, 2‐unit FPDs retained by full‐veneer retainers at 77%, and 3‐unit resin‐bonded FPDs at 63%. No significant difference was found between the four designs (P > 0·05). Up to both 48 and 60 months, the most common causes of failure were endodontic for FPDs retained by full‐veneer retainers, and dislodgement for resin‐bonded FPDs. The 3‐unit fixed‐fixed FPDs retained by full‐veneer retainers had the most favourable prognosis after 48 months for replacing a single missing tooth, but the difference between designs was not statistically significant.