bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel method using cyanobacteria for ecotoxicity test of veterinary antimicrobial agents
Authors: Ando Tomonori , Nagase Hiroyasu , Eguchi Kaoru , Hirooka Takashi , Nakamura Takanori , Miyamoto Kazuhisa , Hirata Kazumasa
Published: June 2007

The effect of antimicrobial agents for veterinary use on the growth of cyanobacteria was investigated by measuring minimum inhibitory concentration, medium effective concentration (EC50), and no-observed-effect concentration of seven antimicrobial agents for eight cyanobacteria. The results demonstrated that the seven antimicrobial agents, even at low concentrations, inhibited the growth of cyanobacteria. Microcystis aeruginosa and Synechococcus sp. had the highest sensitivity to the antimicrobial agents used in the present study. It is considered that the utilization of cyanobacteria would enable easy and highly sensitive assessment of the toxicity of such chemicals as antimicrobial agents. We suggest that cyanobacteria be used for ecotoxicity test in addition to the hitherto established method that uses green algae.
Accumulation of polycyclic aromatic hydrocarbons in rural soils based on mass balances at the catchment scale
Authors: Gocht Tilman , Ligouis Bertrand , Hinderer Matthias , Grathwohl Peter
Published: June 2007

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic organic pollutants that are ubiquitously distributed in the environment at relatively high concentrations. In our study we investigated the long-term fate of atmospheric PAHs in soils of rural areas, resulting from diffuse pollution based on mass balances at the catchment scale. By determining PAHs in several environmental compartments, estimates of soil storages and water fluxes were made and compared with atmospheric deposition. The results indicate that more than 90% of the incoming PAHs remain in the catchments and accumulate in the topsoils. Furthermore, revolatilization of PAHs from soils and degradation in the soils is very limited, resulting in ongoing accumulation in topsoils, in particular for low-volatile PAHs. Combustion-derived carbonaceous particles were detected in atmospheric deposition as well as in the soil samples. Since these particles are very strong adsorbents, they are suspected to play a key role in the environmental fate of the diffuse distributed PAHs.
Structural and functional responses of river biofilm communities to the nonsteroidal anti-inflammatory diclofenac
Authors: Lawrence John R. , Swerhone George D.W. , Topp Edward , Korber Darren R. , Neu Thomas R. , Wassenaar Leonard I.
Published: June 2007

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) that has been detected widely in surface waters in North America and Europe. The impact of diclofenac on river biofilm communities was investigated at exposures of 10 and 100 μg L−1 of diclofenac or its molar equivalent in carbon and nutrients. Experiments were carried out with river water during spring and summer using rotating annular reactors as model systems. Diclofenac or nutrients at 10 μg L−1 were observed to have no significant effect on algal, bacterial, and cyanobacterial biomass in spring, whereas in the summer the nutrient equivalent reduced algal biomass and diclofenac reduced cyanobacterial biomass relative to control biofilms (p < 0.05). In contrast, at 100 μg L−1 diclofenac or nutrients, the result was increased cyanobacterial and bacterial biomass, respectively, relative to control biofilms in spring. In summer, 100 μg L−1 diclofenac significantly increased bacterial biomass and the nutrient treatment had no significant effect (p < 0.05); both treatments resulted in increased biofilm thickness. The glycoconjugate composition of the exopolysaccharide matrix was influenced differentially by the treatments in both seasons. Biolog assessments of carbon use indicated that 100 μg L−1 diclofenac or nutrients resulted in significant depressions in the use of carbon sources in summer and significant increases in spring. Impacts on protozoan and micrometazoan populations also were assessed. Denaturing gradient gel electrophoresis analyses of community DNA and fluorescent in situ hybridization studies indicated that diclofenac had significant effects on the nature of the bacterial community in comparison with control and nutrient-treated river biofilm communities.
Risk assessment of great horned owls (Bubo virginianus) exposed to polychlorinated biphenyls and DDT along the Kalamazoo River, Michigan, USA
Authors: Strause Karl D. , Zwiernik Matthew J. , Im Sook Hyeon , Bradley Patrick W. , Moseley Pamela P. , Kay Denise P. , Park Cyrus S. , Jones Paul D. , Blankenship Alan L. , Newsted John L. , Giesy John P.
Published: June 2007

The great horned owl (GHO; Bubo virginianus) was used in a multiple lines of evidence study of polychlorinated biphenyls (PCBs) and p,p′-dichlorodiphenyltrichloroethane (DDT) exposures at the Kalamazoo River Superfund Site (KRSS), Kalamazoo, Michigan, USA. The study examined risks from total PCBs, including 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQWorld Health Organization [WHo-Avian Toxicity Equivalency Factor [TEF], and total DDTs (sum of DDT, dichlorodiphenyldichloroethylene [DDE], and dichlorodiphenyldichloroethane [DDD]; ΣDDT) by measuring concentrations in eggs and nestling blood plasma in two regions of the KRSS (upper, lower) and an upstream reference area (RA). An ecological risk assessment compared concentrations of the contaminants of concern (COCs) in eggs or plasma to toxicity reference values. Productivity and relative abundance measures for KRSS GHOs were compared with other GHO populations. Egg shell thickness was measured to assess effects of p,p′-DDE. The concentrations of PCBs in eggs were as great as 4.7 × 102 and 4.0 × 104 ng PCB/g, wet weight at the RA and combined KRSS sites, respectively. Egg TEQWHo-Avian calculated from aryl hydrocarbon receptor–active PCB congeners and WHO TEFs ranged to 8.0 and 1.9 × 102 pg TEQWHO-Avian/g, (wet wt) at the RA and combined KRSS, respectively. Egg ΣDDT concentrations were as great as 4.2 × 102 and 5.0 × 103 ng ΣDDT/g (wet wt) at the RA and combined KRSS, respectively. Hazard quotients (HQs) for the upper 95% confidence interval (UCI) (geometric mean) and least observable adverse effect concentration (LOAEC) for COCs in eggs were ≤1.0 for all sites. Hazard quotient values based on the no observable adverse effect concentration (NOAEC) 95% UCI in eggs were ≤1.0, except at the LKRSS (PCB HQ = 3.1; TEQWHO-Avian HQ = 1.3). Productivity and relative abundance measures indicated no population level effects in the UKRSS.
Acute toxicity of arsenic to Daphnia pulex: Influence of organic functional groups and oxidation state
Authors: Shaw Joseph R. , Glaholt Stephen P. , Greenberg Noah S. , Sierra-Alvarez Reyes , Folt Carol L.
Published: June 2007

Investigations were conducted to determine the influence of organic functional groups (i.e., methyl, phenyl) and valence state (i.e., III, V) on acute (48-h) arsenic toxicity in Daphnia pulex. These included toxicity texts with a suite of inorganic (arsenite, arsenate) and organic arsenicals (trivalent and pentavalent methylated arsenicals, roxarsone, p-arsanilic acid). Toxicity, based on median lethal concentrations (LC50 values), clustered the arsenicals into three groups and followed the order (most toxic to least toxic) of monomethylarsonous acid (MMAIII), 120 μg/L > inorganic arsenic, 2,500 to 3,900 μg/L > pentavalent methylated arsenicals and phenylarsonic compounds, 13,800 to 15,700 μg/L. Pentavalent organic arsenicals were less toxic than inorganic forms regardless of functional group. In contrast, the trivalent organic species (MMAIII) was the most toxic arsenical studied. These findings, which are the first to include an aquatic organism, add to the growing body of evidence that find that MMAIII is an extremely toxic intermediate of arsenic methylation and contradict theories of arsenic toxicity that regard methylation as a detoxication event.
Water chemistry-based classification of streams and implications for restoring mined Appalachian watersheds
Authors: Merovich George T. , Stiles James M. , Petty J. Todd , Ziemkiewicz Paul F. , Fulton Jennifer B.
Published: June 2007

We analyzed seasonal water samples from the Cheat and Tygart Valley river basins, West Virginia, USA, in an attempt to classify streams based on water chemistry in this coal-mining region. We also examined temporal variability among water samples. Principal component analysis identified two important dimensions of variation in water chemistry. This variation was determined largely by mining-related factors (elevated metals, sulfates, and conductivity) and an alkalinity-hardness gradient. Cluster analysis grouped water samples into six types that we described as reference, soft, hard, transitional, moderate acid mine drainage, and severe acid mine drainage. These types were statistically distinguishable in multidimensional space. Classification tree analysis confirmed that chemical constituents related to acid mine drainage and acid rain distinguished these six groups. Hard, soft, and severe acid mine drainage type streams were temporally constant compared to streams identified as reference, transitional, and moderate acid mine drainage type, which had a greater tendency to shift to a different water type between seasons. Our research is the first to establish a statistically supported stream classification system in mined watersheds. The results suggest that human-related stressors superimposed on geology are responsible for producing distinct water quality types in this region as opposed to more continuous variation in chemistry that would be expected in an unimpacted setting. These findings provide a basis for simplifying stream monitoring efforts, developing generalized remediation strategies, and identifying specific remediation priorities in mined Appalachian watersheds.
Evaluating polycyclic aromatic hydrocarbons using a yeast bioassay
Authors: Alnafisi Abeer , Hughes Janet , Wang Guangdi , Miller Charles A.
Published: June 2007

Sixteen polycyclic aromatic hydrocarbons (PAHs) were evaluated for the ability to activate aryl hydrocarbon (Ah) receptor signaling in a yeast-based bioassay. Individual PAHs were classified as inactive or as weakly, moderately, or strongly active based on induction of human Ah receptor signaling. Indeno[1,2,3-cd]pyrene, chrysene, benzo[a]anthracene, benzo[a]pyrene, benzo[j]fluoranthene, and benzo[k]fluoranthene were the most potent activators of human Ah receptor signaling. Various mixtures of PAHs had additive or synergistic effects in the bioassay. Environmental samples from the New Orleans (Louisiana, USA) and Detroit (Michigan, USA) areas that were previously analyzed for PAH composition and quantity were tested in this bioassay. Weak but statistically significant relationships were found when the analytically measured levels of PAHs were correlated with sample dilutions that gave 25% effective concentration signaling levels in the Ah receptor assay. We conclude that this Ah receptor signaling assay may be useful for preliminary biomonitoring of samples for PAHs and other Ah receptor ligands.
Aryl hydrocarbon receptor ligand activity of polycyclic aromatic ketones and polycyclic aromatic quinones
Authors: Misaki Kentaro , Kawami Hirofumi , Tanaka Tota , Handa Hiroshi , Nakamura Masafumi , Matsui Saburo , Matsuda Tomonari
Published: June 2007

Polycyclic aromatic ketones (PAKs) and polycyclic aromatic quinones (PAQs) are oxygenated polycyclic aromatic hydrocarbons (PAHs), and reports about the aryl hydrocarbon receptor (AhR) ligand activities of these compounds are few. In this study, activation of AhR by 41 polycyclic aromatic compounds (PACs), focusing especially on PAKs and PAQs, was determined by measuring β-galactosidase activity from a reporter plasmid in yeast engineered to express human AhR and the AhR nuclear translocator proteins and by measuring luciferase activity from mouse hepatoma (H1L1) cells (chemical-activated luciferase expression [CALUX] assay). The PACs used in these experiments included 11 PAKs, seven PAQs, and 21 PAHs. In this study, the PAKs 11H-benzo[a]fluoren-11-one (B[a]FO), 11H-benzo[b]fluoren-11-one (B[b]FO) and 7H-benzo[c]fluoren-7-one and the PAQs 5,12-naphthacenequinone, 1,4-chrysenequinone, and 7,12-benz[a]anthracenequinone showed high AhR activities in H1L1 cells, although these values were not as high as that for benzo[a]pyrene (B[a]P). These PAKs and PAQs showed significantly stronger activities in yeast cells relative to B[a]P. It was predicted that PAKs such as B[a]FO and B[b]FO occupied 0.06% to 1.3% of the total induction equivalents, and each contribution matched the contribution of PAHs such as B[a]P, chrysene, and benz[a]anthracene in gasoline exhaust particulates and airborne particulates using data of CALUX assay.
Perchlorate assessment of the Nakdong and Yeongsan watersheds, Republic of Korea
Authors: Quiñones Oscar , Oh Jeong-Eun , Vanderford Brett , Kim Joon Ha , Cho Jaeweon , Snyder Shane A.
Published: June 2007

The objective of the present study was to conduct a preliminary assessment for perchlorate in surface water, drinking water, and wastewater treatment plant effluent samples obtained from the Nakdong and Yeongsan watersheds in the Republic of Korea. Samples were analyzed for perchlorate using ion chromatography with suppressed conductivity detection (IC-CD) and/or liquid chromatography with tandem mass spectrometry detection (LC-MS/MS). Method reporting limits were 5.0 μg/L for IC-CD and 0.05 μg/L for LC-MS/MS analysis. At perchlorate levels above 5.0 μg/L, IC-CD and LC-MS/MS provided comparable results. The levels of perchlorate detected in the samples procured from the Yeongsan watershed were <5.0 μg/L in each case. However, Nakdong watershed samples contained perchlorate at levels up to 60 μg/L. The highest concentrations of perchlorate were found in surface water samples, although drinking water contained perchlorate at concentrations up to 35 μg/L. In a subset of samples analyzed by LC-MS/MS, chlorate and bromate also were detected at concentrations ranging from <0.10 to 44 μg/L and <0.10 to 2.6 μg/L, respectively. To the best of the authors' knowledge, this is the first perchlorate assessment reported for water sources in the Republic of Korea.
Oviposition site selection: Pesticide avoidance by gray treefrogs
Authors: Takahashi Mizuki
Published: June 2007

Effects of glyphosate-formulated herbicides on nontarget organisms have received much recent attention. Although previous studies have explored the effects of pesticides on growth, development, and mortality of various amphibian species, no studies have tested the potential effects of herbicides on oviposition site selection by amphibians. Recent studies have found that a combination of pesticide and predatory cues lead to significantly increased mortality of tadpoles of several anuran species relative to that caused by pesticide alone. In the present study, I tested two hypotheses: First, adult gray treefrogs avoid oviposition sites based on the presence of glyphosate formulation (Roundup®). Second, pesticide avoidance is manifested to a greater degree when combined with predatory cues. In the spring of 2006, I conducted an outdoor experiment using artificial ponds by setting up four treatments: Predatory fish cue, Roundup (2.4 mg glyphosate acid equivalent [a.e.]/L), a combination of predatory fish cue + Roundup, and a control. This experiment was designed to assess oviposition site choice among the four treatments by gray treefrogs based on the number of eggs laid in each treatment. Gray treefrogs avoided oviposition in pools contaminated with fish cue and/ or Roundup and placed the significant majority of their eggs in control pools, which suggests that breeding adults may be able to prevent lethal exposure of herbicide to their offspring through oviposition site selection. The present study provided the first evidence that the concentration of herbicide that is expected to be found in the field potentially alters oviposition site choice by amphibians. However, the concentration of 2.4 mg a.e./L is unlikely ubiquitous in nature. Thus, the further investigation of environmental relevancy of this finding is critical.
Effect of River Sediment on Phosphorus Chemistry of Similarly Aged Natural and Created Wetlands in the Atchafalaya Delta, Louisiana, USA
Authors: Poach M. E. , Faulkner S. P.
Published: June 2007

The goal of wetland creation is to produce an artificial wetland that functions as a natural wetland. Studies comparing created wetlands to similarly aged natural wetlands provide important information about creation techniques and their improvement so as to attain that goal. We hypothesized that differences in sediment phosphorus accretion, deposition, and chemistry between created and natural wetlands in the Atchafalaya Delta, Louisiana, USA were a function of creation technique and natural river processes. Sediment deposition was determined with feldspar marker horizons located in created and natural wetlands belonging to three age classes (<3, 5–10, and 15–20 yr old). Phosphorus fractions were measured in these deposited sediments and in suspended and bedload sediment from the Atchafalaya River. Bedload sediment had significantly lower iron‐ and aluminum‐bound, reductant‐soluble, and total phosphorus than suspended sediment due to its high sand percentage. This result indicates that wetlands artificially created in the Atchafalaya Delta using bedload sediment will initially differ from natural wetlands of the same age. Even so, similarities between the mudflat stratum of the <1‐ to 3‐yr‐old created wetland and the mudflat stratum of the 15‐ to 20‐yr‐old natural wetland support the contention that created wetlands in the Atchafalaya Delta can develop natural characteristics through the deposition of river suspended sediment. Differences between three created wetland strata, the 15‐ to 20‐yr‐old willow stratum and the <1‐ to 3‐yr‐old willow and mixed marsh strata, and their natural counterparts were linked to design elements of the created wetlands that prevented the direct deposition of the river's suspended sediment.
Sulfamethazine Uptake by Plants from Manure‐Amended Soil
Authors: Dolliver Holly , Kumar Kuldip , Gupta Satish
Published: June 2007

Animal manure is applied to agricultural land as a means to provide crop nutrients. However, animal manure often contains antibiotics as a result of extensive therapeutic and subtherapeutic use in livestock production. The objective of this study was to evaluate plant uptake of a sulfonamide‐class antibiotic, sulfamethazine, in corn (Zea mays L.), lettuce (Lactuca sativa L.), and potato (Solanum tuberosum L.) grown in a manure‐amended soil. The treatments were 0, 50, and 100 μg sulfamethazine mL−1 manure applied at a rate of 56 000 L ha−1 Results from the 45‐d greenhouse experiment showed that sulfamethazine was taken up by all three crops, with concentrations in plant tissue ranging from 0.1 to 1.2 mg kg−1 dry weight. Sulfamethazine concentrations in plant tissue increased with corresponding increase of sulfamethazine in manure. Highest plant tissue concentrations were found in corn and lettuce, followed by potato. Total accumulation of sulfamethazine in plant tissue after 45 d of growth was less than 0.1% of the amount applied to soil in manure. These results raise potential human health concerns of consuming low levels of antibiotics from produce grown on manure‐amended soils.
Biological Aspects of Metal Waste Reclamation with Biosolids
Authors: Stuczynski Tomasz , Siebielec Grzegorz , Daniels Walter L. , McCarty Greg , Chaney Rufus L.
Published: June 2007

Smelter waste deposits pose an environmental threat worldwide. Biosolids are potentialy useful in reclamation of such sites. Biological aspects of revegetation of Zn and Pb smelter wastelands using biosolids are discussed in this report. The goal of the studies was to assess to what extent biosolid treatment would support ecosystem functioning as measured by biological indicators such as enzyme activities of revegetated metal waste or plant growth. Another crucial aspect was related to the assessment of metal transfer to the ecosystem which could affect the health of local fauna and also create a food chain risk. A field experiment was conducted on a smelter waste deposit in Piekary Slaskie, Silesia, Poland, with two separate fields—established on wastes from the Welz and Doerschel smelting processes. The tested methods allowed revegetation of the fields—application of municipal biosolid at the rate 300 dry t ha−1 combined with the incorporation of commercial lime in a mixed oxide and carbonate form at the rate of 1.5 and 30 t for Welz waste or use of a 30 cm by‐product lime cap followed by incorporation of biosolid at a rate of 300 t ha−1 for the more acidic Doerschel waste. Studies on biological activities demonstrated that the reclamation methods used are an effective way to establish new, fully‐functioning ecosystems that support plant growth. They also provided strong evidence that forage crops grown on Zn, Cd and Pb contaminated sites reclaimed using lime and biosolids do not pose identified risk for wildlife and food safety.
Meta‐Analysis of Nitrogen Removal in Riparian Buffers
Authors: Mayer Paul M. , Reynolds Steven K. , McCutchen Marshall D. , Canfield Timothy J.
Published: June 2007

Riparian buffers, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and reducing nitrogen loads entering water bodies. Riparian buffer width is thought to be positively related to nitrogen removal effectiveness by influencing nitrogen retention or removal. We surveyed the scientific literature containing data on riparian buffers and nitrogen concentration in streams and groundwater to identify trends between nitrogen removal effectiveness and buffer width, hydrological flow path, and vegetative cover. Nitrogen removal effectiveness varied widely. Wide buffers (>50 m) more consistently removed significant portions of nitrogen entering a riparian zone than narrow buffers (0–25 m). Buffers of various vegetation types were equally effective at removing nitrogen but buffers composed of herbaceous and forest/herbaceous vegetation were more effective when wider. Subsurface removal of nitrogen was efficient, but did not appear to be related to buffer width, while surface removal of nitrogen was partly related to buffer width. The mass of nitrate nitrogen removed per unit length of buffer did not differ by buffer width, flow path, or buffer vegetation type. Our meta‐analysis suggests that buffer width is an important consideration in managing nitrogen in watersheds. However, the inconsistent effects of buffer width and vegetation on nitrogen removal suggest that soil type, subsurface hydrology (e.g., soil saturation, groundwater flow paths), and subsurface biogeochemistry (organic carbon supply, nitrate inputs) also are important factors governing nitrogen removal in buffers.
Threatening of cerebrovascular insufficiency within surgery of carotid artery restenosis
Authors: Palkovic Stefan , Tjan Tonny , Fischer Bernhard , Wassmann Hansdetlef
Published: June 2007

Surgical intervention for extracranial carotid artery stenosis remains a major potential therapeutic modality for the prevention of stroke. Nevertheless, every kind of surgical technique for carotid entarterectomy (CEA) has its specific complications, compromising the final surgical result. The authors report about a 70-year old man, suffering from recurrent transient ischemic attacks by suspected internal carotid artery (ICA) re-stenosis, 11 and 13 years after CEA with patch angioplasty. In relation to neurological symptomatic and angiographic appearance of ICA re-stenosis an open surgery of the left ICA was preferred. Intraoperatively the old patch material was such vulnerable that it was not possible to maintain the continuity of ECA and ICA or CCA and ICA. Consequently reconstruction and replacement of ICA and ECA with 6 mm Gore-Tex grafts was performed. Follow-up three years after surgery showed no symptoms of insufficient brain metabolism as well as a good flow within the grafts. Patch angioplasty by CEA seems to be favourable to reduce the risk of early ICA re-stenosis but for all that there are other accompanying problems, which can compromise utility of patch technique. For this the authors prefer a patient adapted surgical treatment, based not only on so far not significant data but moreover on personal experience.
Effects of an adapted intravenous amiodarone treatment protocol in horses with atrial fibrillation
Authors: de CLERCQ D. , van LOON G. , BAERT K. , TAVERNIER R. , CROUBELS S. , de BACKER P. , DEPREZ P.
Published: June 2007

Reason for performing study: Good results have been obtained with a human amiodarone (AD) i.v. protocol in horses with chronic atrial fibrillation (AF) and a pharmacokinetic study is required for a specific i.v. amiodarone treatment protocol for horses.

Objectives: To study the efficacy of this pharmacokinetic based i.v. AD protocol in horses with chronic AF.

Methods: Six horses with chronic AF were treated with an adapted AD infusion protocol. The protocol consisted of 2 phases with a loading dose followed by a maintenance infusion. In the first phase, horses received an infusion of 6.52 mg AD/kg bwt/h for 1 h followed by 1.1 mg/kg bwt/h for 47 h. In the second phase, horses received a second loading dose of 3.74 mg AD/kg bwt/h for 1 h followed by 1.31 mg/kg bwt/h for 47 h. Clinical signs were monitored, a surface ECG and an intra‐atrial electrogram were recorded. AD treatment was discontinued when conversion or any side effects were observed.

Results: Three of the 6 horses cardioverted successfully without side effects. The other 3 horses did not convert and showed adverse effects, including diarrhoea. In the latter, there were no important circulatory problems, but the diarrhoea continued for 10–14 days. The third horse had to be subjected to euthanasia because a concomitantSalmonellainfection worsened the clinical signs.

Conclusion: The applied treatment protocol based upon pharmacokinetic data achieved clinically relevant concentrations of AD and desethylamiodarone.

Potential relevance: Intravenous AD has the potential to be an alternative pharmacological treatment for AF in horses, although AD may lead to adverse drug effects, particularly with cumulative dosing.
Acute in vivo interactions of Helicobacter equorum with its equine host
Authors: MOYAERT H. , DECOSTERE A. , PASMANS F. , BAELE M. , CEELEN L. , SMITS K. , DUCATELLE R. , HAESEBROUCK F.
Published: June 2007

Reasons for performing study: A novel urease‐negative Helicobacter species has been isolated from faecal samples of clinically healthy horses, but no information is available about the main sites of colonisation in the equine gastrointestinal tract nor is the pathogenic potential of this microorganism known. An experimental infection in horses was therefore carried out.

Methods: Four horses were infected with H. equorum strain CCUG 52199T and subjected to euthanasia at 10 (n = 2) and 30 days (n = 2) post inoculation. A fifth animal was inoculated with phosphate buffered saline and used as control. Gastrointestinal samples were examined histologically and bacteriologically. These samples, as well as faecal material collected at regular intervals, were also subjected to PCR analysis.

Results: All horses remained clinically healthy and no specific macroscopic lesions were identified, nor were there any microscopic changes. H. equorum‐DNA was detected in the faeces during the whole experiment in all infected animals but not in the negative control. Sites of colonisation were caecum, colon and rectum.

Conclusions: H. equorum is able to colonise the equine lower bowel and is excreted in faeces without apparent pathology. No association between the presence of the organism and gastrointestinal disease was demonstrated.
Physiology of equine performance and associated tests of function
Authors: EVANS D. L.
Published: June 2007

This review addresses the physiology of performance horses in the context of functional tests aimed at assisting clinicians in the search for explanations of the individual's limitations, actual or perceived as below expectation. The intention is to assist clinicians who are faced frequently by owners or trainers seeking explanations for poor performance; and for research workers as a basis on which to proceed in their search for new methodologies, particularly those that can be applied in the field as for treadmill exercise.

The review sets out fundamental physiological pathways, the entailment of which may represent a limiting factor to performance, while taking into account the individual's status, including anamnesis and the possibility of actual disease being present.

Tests that assess the possible roles of several body systems, as causes of limited performance, are discussed. These systems include pulmonary, cardiovascular and neuromuscular systems. The evaluation of anaerobic and aerobic energy pathways is also discussed.

Emphasis is given to the assessment of pulmonary ventilation by techniques such as spirometry and ergospirometry. These techniques are considered to be of particular potential for further development.
Restructuring Teachers’ Work and Trade Union Responses in England: Bargaining for Change?
Authors: Stevenson Howard
Published: June 2007

A key feature of current school-sector reform in England is the restructuring of teachers’ work and the increased use of support staff to undertake a range of activities previously undertaken by teachers. Supporters speak of a new teacher professionalism focused on the “core task” of teaching. Critics fear deprofessionalization through a process of deskilling, work intensification, and labor substitution. This article uses labor process theory and empirical data to analyze recent developments in teachers’ work and links these to the different ways in which teacher trade unions have bargained over reform. The article argues that workforce reform cannot be analyzed separately from the trade union strategies that seek to influence policy and that the emergence of a type of “reform unionism” in England represents the integration of product and process in policy.
Estimating Causal Effects Using School-Level Data Sets
Authors: Stuart Elizabeth A.
Published: June 2007

Education researchers, practitioners, and policymakers alike are committed to identifying interventions that teach students more effectively. Increased emphasis on evaluation and accountability has increased desire for sound evaluations of these interventions; and at the same time, school-level data have become increasingly available. This article shows researchers how to bridge these two trends through careful use of school-level data to estimate the effectiveness of particular interventions. The author provides an overview of common methods for estimating causal effects with school-level data, including randomized experiments, regression analysis, pre–post studies, and nonexperimental comparison group designs. She stresses the importance of careful design of nonexperimental studies, particularly the need to compare units that were similar before treatment assignment. She gives examples of analyses that use school-level data and concludes with advice for researchers.
Die Vegetationsentwicklung – erfasst am Individuum und über den Raum | Changes in plant development – monitored on the individual plant and over geographical area
Authors: Brügger Robert , Studer Sibylle , Stöckli Reto
Published: June 2007

The phenological development of plants provides information about the influence of weather on vegetation and may be assessed on both the individual plant level and on a global level. Since 2000, Switzerland has had a phenological monitoring network for forest trees which records the seasonality and is complementary to the ICP-Forests Assessments (International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests). A comparison of leaf discoloration at the monitoring plot Kaiseraugst has shown that beech, oak and ash trees have all been affected differently as a result of the summer drought of 2003. In 2004,a digital picture data base was developed for the research project 'Phenophot' at the Geographical Institute Berne which allows the phenological observations to become objective and reproducible. A Phenological Growing Index (PGI) is being derived from the red-green-blue channel data of the digital sensor, which complements the information of satellite based vegetation indices. These indices include the Normalized Differenced Vegetation Index (NDVI) on a sub-pixel level which provides improved accuracy for the information on the character and beginning and ending of the vegetation period. The first comparison of the phenological spring index from the satellite based NDVI revealed that the annual start of spring is reproduced most accurately by determining a threshold of the NDVI.
Cover Picture: Covalent Functionalization of Carbon Nanohorns with Porphyrins: Nanohybrid Formation and Photoinduced Electron and Energy Transfer (Adv. Funct. Mater. 10/2007)
Authors: Pagona G. , Sandanayaka A. S. D. , Araki Y. , Fan J. , Tagmatarchis N. , Charalambidis G. , Coutsolelos A. G. , Boitrel B. , Yudasaka M. , Iijima S. , Ito O.
Published: June 2007

A transmission electron microscopy image of the spherical superstructure of dahlia flowerlike carbon nanohorns (CNHs), functionalized at the conical tips with porphyrins (H2P), is shown, together with an illustration of the architecture of the novel CNH–H2P nanohybrid material. Nikos Tagmatarchis, Osamu Ito, and co‐workers report on the preparation and photophysical properties of this material on p. 1705. Photo‐excitation of H2P with visible light results in reduction of the CNHs with a simultaneous oxidation of the porphyrin moiety, resulting in a charge‐separated state; CNH•––H2P•+.

The covalent attachment of carbon nanohorns (CNHs) to α‐5‐(2‐aminophenyl)‐α‐15‐(2‐nitrophenyl)‐10,20‐bis(2,4,6‐trimethyl‐phenyl)‐porphyrin (H2P) via an amide bond is accomplished. The resulting CNH–H2P nanohybrids form a stable inklike solution. High‐resolution transmission electron microscopy (HRTEM) images demonstrate that the original dahlia‐flowerlike superstructure of the CNHs is preserved in the CNH–H2P nanohybrids. Steady‐state and time‐resolved fluorescence studies show efficient quenching of the excited singlet state of H2P, suggesting that both electron and energy transfer occur from the singlet excited state of H2P to CNHs, depending on the polarity of the solvent. In the case of electron transfer, photoexcitation of H2P results in the reduction of the nanohorns and the simultaneous oxidation of the porphyrin unit. The formation of a charge‐separated state, CNH•––H2P•+, has been corroborated with the help of an electron mediator, hexyl‐viologen dication (HV2+), in polar solvents. Moreover, the charge‐separated CNH•––H2P•+ states have been identified by transient absorption spectroscopy.
Synthetic and catalytic investigations of ruthenium(III) complexes with triphenylphosphine/triphenylarsine and tridentate Schiff base
Authors: Priyarega S. , Prabhakaran R. , Aranganayagam K. R. , Karvembu R. , Natarajan K.
Published: June 2007

The synthesis and characterization of several hexa‐coordinated ruthenium(III) complexes of the type [RuCl(PPh3)2(L)] (L = dibasic tridentate ligand derived by the condensation of salicylaldehyde/o‐vanillin with o‐aminophenol/o‐aminothiophenol) are reported. IR, electronic, EPR spectral data and redox bahaviour of the complexes are discussed. An octahedral geometry has been tentatively proposed for all the complexes. The new complexes were found to be effective catalysts for the oxidation of benzyl alcohol and cyclohexanol to benzaldehyde and cyclohexanone respectively using N‐methylmorpholine‐N‐oxide as a co‐oxidant. Copyright © 2007 John Wiley & Sons, Ltd.
Novel adamantane‐containing epoxy resin
Authors: Su Xiaoming , Jing Xinli
Published: June 2007

A novel adamantane‐containing epoxy resin diglycidyl ether of bisphenol‐adamantane (DGEBAda) was successfully synthesized from 1,3‐bis(4‐hydroxyphenyl)adamantane by a one‐step method. The proposed structure of the epoxy resin was confirmed with Fourier transform infrared, 1H‐NMR, gel permeation chromatography, and epoxy equivalent weight titration. The synthesized adamantane‐containing epoxy resin was cured with 4,4′‐diaminodiphenyl sulfone (DDS) and dicyandiamide (DICY). The thermal properties of the DDS‐cured epoxy were investigated with differential scanning calorimetry and thermogravimetric analysis (TGA). The dielectric properties of the DICY‐cured epoxy were determined from its dielectric spectrum. The obtained results were compared with those of commercially available diglycidyl ether of bisphenol A (DGEBA), a tetramethyl biphenol (TMBP)/epoxy system, and some other associated epoxy resins. According to the measured values, the glass‐transition temperature of the DGEBAda/DDS system (223°C) was higher than that of the DGEBA/DDS system and close to that of the TMBP/DDS system. TGA results showed that the DGEBAda/DDS system had a higher char yield (25.02%) and integral procedure decomposition temperature (850.7°C); however, the 5 wt % degradation temperature was lower than that of DDS‐cured DGEBA and TMBP. Moreover, DGEBAda/DDS had reduced moisture absorption and lower dielectric properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Biodegradable double‐layer films based on biological resources: Polyhydroxybutyrate and cellulose
Authors: Cyras Viviana P. , Commisso Ma. Soledad , Mauri Adriana N. , Vázquez Analía
Published: June 2007

A novel biocomposites double‐layer films using polyhydroxybutyrate (PHB) and cellulose paper were produced. The biocomposites were prepared by the solvent‐casting method (with chloroform). Films of the blends were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FTIR), X‐ray (XR) and surface roughness measurements. Moisture absorption, water absorption and water vapor permeation of films has been investigated. The PHB impregnated the fibers of cellulose paper and it was on the valley of paper structure. The double‐layer films showed diminutions in the moisture absorption, in the water abortion, in water vapor permeation and in surface roughness. According to contact angle, surface free energies and the barrier properties of the films can be considered more hydrophobic. The experimentally observed tensile properties (modulus and tensile strength) of double‐layer films with different content of PHB were determined. Measurements show the tensile strength and modulus of cellulose paper increases with the percentage of PHB. SEM photomicrographs of the fractured films surfaces were also analyzed. It was possible to obtain a biodegradable material with little amount of PHB to improve the barrier and the mechanical properties of cellulose paper, taking advantage of the good properties of both materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation and characterization of nylon‐6/PPy/MMT composite of nanocomposite
Authors: Peighambardoust S. Jamal , Pourabbas Behzad
Published: June 2007

Series of composites consisting of polypyrrole/montmorillonite nanocomposites in the matrix of Nylon6 has been synthesized and characterized in this work. The composites were processable, so that test samples were prepared by compression‐molding of the materials for electrical property measurements. Intercalated structures were confirmed by wide‐angle X‐ray diffraction and TEM studies for PPy/MMT nanocomposites. A two‐phase structure was determined for the fused samples consisting of two separated N6 and PPy phases by using scanning electron microscopy analyses. A conductivity threshold was measured at 15%(w/w) loading level of PPy in the composites. Electrical resistivity–temperature behavior of the samples was investigated and a resistivity peak was observed at 100°C for the samples. It was proved that the glass transition temperature of PPy around 100°C should be the responsible factor for the observed resistivity peak, as studied by thermogravimetic analysis and differential scanning calorimetry thermal methods. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Clinical criteria for systemic lupus erythematosus precede diagnosis, and associated autoantibodies are present before clinical symptoms
Authors: Heinlen Latisha D. , McClain Micah T. , Merrill Joan , Akbarali Yasmin W. , Edgerton Colin C. , Harley John B. , James Judith A.
Published: June 2007

Objective

Specific events that occur during the development of systemic lupus erythematosus (SLE) can be quite variable among individual patients. The aim of this study was to identify patterns that distinguish early clinical events in SLE and to assess whether the presence of associated autoantibodies precedes the fulfillment of clinical criteria.

Methods

Through a retrospective chart review of military medical records, 130 patients who met the American College of Rheumatology (ACR) criteria for the classification of SLE were identified. The initial time at which each criterion was fulfilled was recorded. Autoantibody analysis was performed on serum samples, using enzyme‐linked immunosorbent assays or immunofluorescence.

Results

The clinical features that were observed earliest were discoid rash and seizures, which developed a mean 1.74 and 1.70 years, respectively, before the diagnosis of SLE; however, arthritis was the criterion that was most commonly observed before diagnosis. The presence of IgG rheumatoid factor (IgG‐RF) preceded the development of arthritis in 15 (94%) of the 16 patients who were positive for IgG‐RF and in whom arthritis developed (Z = 10.2, P < 0.0001). Analogously, IgM‐RF appeared before the development of arthritis in 13 (76%) of 17 patients. Anti–double‐stranded DNA antibodies were associated with renal disease and appeared before evidence of nephritis in most patients (92%) (Z = 13.3, P < 0.0001). An analysis of the appearance of autoantibodies compared with the appearance of clinical criteria not associated with them revealed no significant temporal relationship.

Conclusion

Symptoms associated with the ACR criteria for classification of SLE are commonly present before the diagnosis of SLE, and development of organ‐associated autoantibodies generally precedes the appearance of their associated clinical features.
Increased macrophage activation mediated through toll‐like receptors in rheumatoid arthritis
Authors: Huang QiQuan , Ma Yingyu , Adebayo Adedamola , Pope Richard M.
Published: June 2007

Objective

Macrophages are the major source of inflammation mediators that are important in the pathogenesis of rheumatoid arthritis (RA). This study was undertaken to analyze macrophages obtained from the joints of RA patients in order to characterize the expression of Toll‐like receptor 2 (TLR‐2) and TLR‐4 and the responses to TLR ligation.

Methods

Cells were isolated from the synovial fluid (SF) of RA patients or patients with other forms of inflammatory arthritis. Cell surface TLR‐2 and TLR‐4 expression and intracellular tumor necrosis factor α (TNFα) and interleukin‐8 (IL‐8) expression by CD14+ macrophages were determined by flow cytometry. Peptidoglycan (PG) and lipopolysaccharide (LPS) were used as ligands for TLR‐2 and TLR‐4, respectively.

Results

The expression of TLR‐2 and TLR‐4 was increased on CD14+ macrophages from the joints of RA patients compared with that on control in vitro–differentiated macrophages or control peripheral blood monocytes. Neither TLR‐2 expression nor TLR‐4 expression differed between RA and other forms of inflammatory arthritis. However, PG‐ and LPS‐induced TNFα expression and IL‐8 expression were greater with RA SF macrophages than with those obtained from the joints of patients with other forms of inflammatory arthritis or with control macrophages. PG‐induced TNFα expression and IL‐8 expression were highly correlated with TLR‐2 expression in normal macrophages, but not with that in macrophages obtained from joints of RA patients or patients with other forms of inflammatory arthritis.

Conclusion

TLR‐2 and TLR‐4 ligation resulted in increased activation of RA synovial macrophages compared with those from patients with other forms of inflammatory arthritis or compared with control macrophages. Factors other than the level of TLR‐2 and TLR‐4 expression contributed to the increased activation of RA SF macrophages. These observations support the notion of a potential role for activation through TLR‐2 and TLR‐4 in the inflammation and joint destruction of RA.
Resistance of rheumatoid arthritis patients to changing therapy: Discordance between disease activity and patients' treatment choices
Authors: Wolfe Frederick , Michaud Kaleb
Published: June 2007

Objective

Despite advances in rheumatoid arthritis (RA) treatment, patients' decisions regarding therapy often deviate from expert recommendation. This study was undertaken to investigate patients' acceptance and satisfaction with therapy, willingness to change therapy, and reasons for not changing.

Methods

Participants (n = 6,135) completed an 11‐item questionnaire concerning treatment preferences. Eight questions assessed reasons for not wanting to change therapy. The contribution of individual predictors was determined by logistic regression analysis.

Results

Questionnaire responses showed that 63.8% of the patients would not want to change therapy as long as their condition didn't get worse; 77.3% were satisfied with their medications, while 9.4% were dissatisfied. These assessments were weakly related to RA activity and functional status. Side effects had occurred in 22.4% of the patients during the previous 6 months, and in 65.5% at some period during their lifetime. Predictors of unwillingness to change therapy were satisfaction with RA control, which had an odds ratio (OR) of 6.8 (95% confidence interval [95% CI] 5.8–8.0), risk of side effects (OR 4.4 [95% CI 3.8–5.2]), physician opinion (OR 1.9 [95% CI 1.6–2.2]), fear of loss of control (OR 1.8 [95% CI 1.6–2.1]), lack of better medications (OR 1.4 [95% CI 1.2–1.6]), and costs (OR 1.3 [95% CI 1.1–1.6]). There was little difference in results between patients who were receiving biologic agents and those who were not.

Conclusion

There is substantial discrepancy between declared satisfaction with therapy and measured RA activity and functional status. Most RA patients are satisfied with their therapy, even many with abnormal scores. Fear of loss of control of RA and fear of side effects are major patient concerns. Maintenance of current status, rather than future improvement, appears to be a high priority for patients.