bluuebunny/crossref_metadata_2025_split huggingface dataset:
Life‐history traits of standard and autochthonous cladocerans: I. Acute and chronic effects of acetylsalicylic acid
Authors: Marques Catarina R. , Abrantes Nelson , Gonçalves Fernando 
Published: September 2004

AbstractPharmaceuticals have been recognized as an important group of aquatic micropollutants, mainly because of their biologically active nature. Acetylsalicylic acid (ASA), which is the active compound of Aspirin® and many other pharmaceuticals, is consumed in large quantities every year. Therefore, its acute and chronic effects on standard (Daphnia magna) and autochthonous (Daphnia longispina) daphnids were investigated. The results showed that ASA impaired the survivorship, reproduction, and growth of the cladoceran species. The standard daphnid was the more tolerant species in acute assays (48‐h EC50 = 1293.05 mg/L; D. longispina: 48‐h EC50 = 647.31 mg/L); whereas the autochthonous daphnid seemed to be more resistant under chronic exposure to ASA, mainly its population‐level traits. Despite this, the observed effect concentrations were much higher than the environmental concentrations of ASA. Notwithstanding this, the impairment of individual‐level traits is likely to occur at environmental levels as an ultimate response to long‐term exposure. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 518–526, 2004.
Sonographic cervical length in singleton pregnancies with intact membranes presenting with threatened preterm labor
Authors: Fuchs I. B. , Henrich W. , Osthues K. , Dudenhausen J. W. 
Published: September 2004

AbstractObjectiveLess than 10% of women presenting with preterm contractions progress to active labor and delivery. This study investigates whether cervical length measurements by ultrasound can discriminate between true and false labor in women presenting with threatened preterm labor.MethodsCervical length was measured by transvaginal ultrasound in 253 women with singleton pregnancies presenting with painful uterine contractions at a median age of 31 (range, 24–35) weeks of gestation. Women presenting in active labor, defined by the presence of cervical dilatation of ≥ 3 cm, those with ruptured membranes and those that underwent prior or subsequent cervical cerclage were excluded from the study. The clinical management was determined by the attending obstetrician without taking into account the cervical length. Primary outcome of the study was delivery within 7 days of presentation based on the results of randomized studies on the use of tocolytics in women with preterm labor that reported a prolongation of pregnancy by 7 days.ResultsDelivery within 7 days of presentation occurred in 21/253 (8.3%) pregnancies and this was inversely related to cervical length. Receiver–operating characteristics (ROC) curves established a cervical length of 15 mm as the most relevant cut‐off level for the prediction of preterm delivery within 7 days. In 217 cases the cervical length was ≥ 15 mm and only four of these (1.8%) delivered within 7 days. In the 36 women with cervical length < 15 mm, delivery occurred in 17 (47.2%) within 7 days. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length, contraction frequency at presentation, previous history of preterm delivery and vaginal bleeding. There was no significant contribution from gestation at presentation, ethnic origin, maternal age, parity, cigarette smoking or the administration of tocolysis, antibiotics or steroids. Similar results were shown in a subanalysis of 162 patients presenting at a gestational age below 32 weeks: 9/19 patients (47.4%) with a cervical length below 15 mm delivered within 7 days compared to 3/143 (2.1%) with a cervical length ≥ 15 mm. Univariate as well as multivariate analyses confirmed cervical length to be a significant independent predictor of delivery within 7 days in this population.ConclusionsSonographic measurement of cervical length helps to avoid overdiagnosis of preterm labor in women with preterm contractions and intact membranes. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
PVC modification through polymerization of a monomer absorbed in porous suspension‐type PVC particles
Authors: Narkis M. , Shach‐Caplan M. , Haba Y. , Silverstein M. S. 
Published: September 2004

AbstractIn‐situ polymerization is the polymerization of one monomer in the presence of another polymer. It can be performed by sequential emulsion polymerization, or by reactions in the melt, in the solid phase, or in solution. The current report describes two methods to obtain poly(vinyl chloride) (PVC) modification through polymerization of a monomer absorbed in commercial porous suspension‐type PVC particles. The generated modified PVC products differ significantly in their structure and properties. The first approach includes absorption of a monomer/peroxide solution within porous suspension‐type PVC particles, followed by polymerization/crosslinking in the solid state at 80°C in an aqueous stabilizer‐free dispersion. The monomer/crosslinker pairs selected are styrene/DVB (divinyl benzene), methylmethacrylate/EGDMA (ethylene glycol dimethacrylate), butyl acrylate/EGDMA, and ethylhexyl acrylate/EGDMA. The influence of composition and nature of the polymerizing/crosslinking constituents on the modified PVC particle structure was studied by microscopy methods, porosity measurements, and dynamic mechanical behavior (DMTA). The level of molecular grafting between PVC and the modifying polymer was determined by solvent extraction experiments. This work shows that the different monomers used represent distinct courses of monomer transport through the PVC particles. The characteristics of the modified PVC particle indicate that the polymerization/crosslinking process occurs in both the PVC bulk, i.e., within the walls constituting a particle, and in the PVC pores. No indication of chemical intermolecular interaction within the modified PVC particles was found. In the second approach, a solution of monomer, initiator, and a crosslinking agent is absorbed in commercial suspension‐type porous PVC particles, thus forming a dry blend. This dry blend is subsequently reactively polymerized in a twin‐screw extruder at an elevated temperature, 180°C, in the molten state. The properties of the reactively extruded PVC/PMMA blends are compared with those of physical blends at similar compositions. Owing to the high polymerization temperature, short‐chain polymers are formed in the reactive polymerization process. Reactively extruded PVC/PMMA blends are transparent, form single‐phase morphology, have a single Tg, and show mechanical properties comparable with those of the neat PVC. The resulting reactively extruded PVC/PMMA blends have high compatibility. J. Vinyl Addit. Technol. 10:109–120, 2004. © 2004 Society of Plastics Engineers.
Effect of metal stearate antacid on the melt stabilization performance of phenolic/phosphite antioxidants in metallocene LLDPE. Part 2: Discoloration
Authors: Hoàng Eric M. , Liauw Christopher M. , Allen Norman S. , Fontán Eusebio , Lafuente Pilar 
Published: September 2004

AbstractThe first part of this series of papers indicated that the melt stabilization performance of phenol/phosphite/metal stearate combinations in metallocene LLDPE (mLLDPE) was influenced by the purity of the fatty acid salt. In this second part, it is shown that the quality of the metal stearate has a direct influence on the discoloration of the aforementioned formulations in the melt state. On the basis of the peroxide and oxide impurity levels in the metal stearates (Part 1), it is suggested that discoloration is directly related to the formation of oxidative transformation products of the phenolic antioxidant. Furthermore, it was observed that the calcium stearates discolored upon aging in air at processing temperatures, while zinc stearates did not. Such discoloration is believed to be partly due to the combination of high levels of conjugated systems consisting of unsaturation and carbonyl groups formed during aging. J. Vinyl Addit. Technol. 10:144–148, 2004. © 2004 Society of Plastics Engineers.
Development of a portable x‐ray fluorescence spectrometer equipped with two monochromatic x‐ray sources and silicon drift detector and field analysis of Islamic glasses at an excavation site in Egypt
Authors: Nakai I. , Yamada S. , Terada Y. , Shindo Y. , Utaka T. 
Published: September 2004

AbstractA portable x‐ray fluorescence spectrometer equipped with a silicon drift detector (SDD) and a digital signal processor (DSP) was developed for in‐field analysis of archeological samples at an excavation site. This spectrometer allows us to carry out highly sensitive analyses of various elements with atomic numbers down to Na in air by using two monochromatic x‐ray sources obtained by doubly bent toroidal monochromators of graphite (0002) (Pd Kα for medium–heavy elements) and PET (200) (Pd Lα for light elements) and white x‐rays with a Zr filter excited at 40 kV for heavy elements. The detection limit was 0.31% for Al and 4 ppm for Sr in a standard cement sample. The spectrometer was set in a room of the excavation laboratory at al‐Tūr Sinai in the Sinai Peninsula in Egypt in the summer of 2001. The Middle Eastern Culture Center has been conducting an excavation of the sites in al‐Tūr al‐Kilani and Rāya, which were important port cities of Red Sea trade from early Islamic periods: al‐Tūr (A.D.14–20) and Rāya (A.D.8–12). The instrument was operated without any problems and 222 glass objects, 26 pottery sherds, seven pigments and 88 metallic objects were analyzed non‐destructively during a 1 month stay. Since this was the first chemical analysis done at the sites, many important archaeological findings were obtained in the present study. Glass objects were successfully classified based on their chemical compositions. Characterization of stained (luster) glasses was conducted. Copyright © 2004 John Wiley & Sons, Ltd.
A new approach to the determination of the Fano factor for semiconductor detectors
Authors: Papp T. , Lépy M.‐C. , Plagnard J. , Kalinka G. , Papp‐Szabó E. 
Published: September 2004

AbstractValues of the Fano factor are widely scattered in the literature, indicating the difficulties in its determination. We chose to analyze both the escape peaks and parent peaks of Ge detector spectra where the parent peak penetration depth and the escape peak escape depth are much larger than the size of the incomplete charge collection region. Hence, the escape peaks are expected to be free of low‐energy tailing as, although the actually deposited energy is low, it is deposited beyond the incomplete charge collection region. It was found that the product of electron–hole pair creation energy (ε) and the Fano factor (F) has an energy dependence at low energies, as is expected from electron transport theories. Although ε is expected to have its own energy dependence, if a reference value of 2.96 eV is assumed for ε, then the Fano factor values varied between 0.059 and 0.083. The escape peak is less advantageous for Si, hence a different method was used for Si(Li) detectors. Assuming the reference value of 3.8 eV for ε, the Fano factor was found to be 0.063 at 5.9 keV x‐ray energy. We consider the Fano factors reported here as upper limits, rather than the mean values. Copyright © 2004 John Wiley & Sons, Ltd.
Empirical coefficients models for x‐ray fluorescence analysis of intermediate‐thickness samples
Authors: Sitko Rafał 
Published: September 2004

AbstractEmpirical coefficients models for correction of matrix effects in intermediate‐thickness samples are presented. Two proposed mathematical models correct simultaneously matrix effects and various masses per unit area of the samples. In the first model, it is necessary to know the masses per unit area of the samples and in the second model masses are predicted from the scattered radiation. To calculate coefficients of the models, a series of multi‐element intermediate‐thickness standards with various compositions and various masses per unit area are required. The models were tested experimentally using synthetic samples pressed into pellets and geological certificate reference materials collected on a membrane filter. The calculated concentrations were in good agreement with the certificate values. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of and correction for moisture in rocks, soils and sediments on in situ XRF analysis
Authors: Ge Liangquan , Lai Wanchang , Lin Yanchang 
Published: September 2004

AbstractThis paper discusses the influence of water contained in rocks, soils and sediments on in situ XRF analysis with a portable XRF analyzer. Water in natural rocks, soil and sediments absorbs the characteristic x‐rays from the elements and also causes the primary radiation from the excitation sources to scatter, which results in a decrease in the intensity of characteristic x‐rays and an increase in the intensity of scattered x‐rays in a fluorescence spectrum. A method for correcting for the influence of the water on the analysis of wet samples is proposed, based on the fact that the intensity of scattered radiation is directly proportional to the water content of wet samples. Tests on a set of wet soil samples showed that the method can effectively correct for the influence of the water in wet samples up to a 20% water content. The method was also applied to the analysis of soil with an IED‐2000P XRF analyzer in a copper prospecting area in Yunnan, China. The results show satisfactory agreement of the results for Cu, Zn and Sr analyses before and after rain. Copyright © 2004 John Wiley & Sons, Ltd.
A prospective study of the relationship between musculoskeletal or psychological complaints and muscular responses to standardized cognitive and motor tasks in a working population
Authors: Steingrómsdóttir Ólöf Anna , Vøllestad Nina Køpke , Knardahl Stein 
Published: September 2004

AbstractThe present study sought to determine the relationship between musculoskeletal or psychological complaints and muscular responses to standardized cognitive and motor tasks. The prospective study design examined (i) whether complaint severity predicts muscular responses during standardized tasks and (ii) whether the muscular responses predict changes in complaint severity over one year. Musculoskeletal and psychological complaints were recorded by monthly reports the four months preceding and 12 months succeeding a work session in the laboratory; complaint‐severity indices were computed from complaint‐severity scores (intensity score × duration score). Surface electromyography (EMG) was recorded bilaterally from the upper trapezius, middle deltoid, and forearm extensor muscles in 45 post‐office workers (30 women) during two identical task series. Between the series, exhausting submaximal muscle contractions (25% of peak torque) were performed. In adjusted regression models, no relations between musculoskeletal complaints the last four months and muscle activity during the task series were found. However, psychological complaints the last four months predicted higher muscle activity levels and a steeper rise in muscle activity in the muscles not engaged in motor task performance. Sleep disturbance was the strongest individual predictor of increased muscle responses. In contrast, psychological complaints the last four months predicted lower EMG levels in the task‐engaged muscle during the complex‐choice‐reaction‐time tasks. None of the muscle‐activity responses to the standardized tasks predicted changes in severity of musculoskeletal or psychological complaints over the subsequent one‐year period. In conclusion, psychological complaints predict different responses in task‐engaged and non‐involved muscles during cognitive and motor tasks. Musculoskeletal complaints did not predict responses to the tasks.
Quality of Nephrops as food for Atlantic cod (Gadus morhua L.) with possible implications for fisheries management
Authors: Björnsson Björn , Álvaro Dongala Dombaxe Maria 
Published: September 2004

Abstract
Nephrops was found to be of low quality as food for cod. In a laboratory experiment the mean specific growth rate of 1 kg cod was 0.184 and 0.415% d−1 when fed to satiation on Nephrops and capelin, respectively. This large difference in growth rate resulted not only from less intake of Nephrops (1.19 kg cod−1) than capelin (1.55 kg cod−1) but also because more Nephrops (4.6 kg) than capelin (2.2 kg) were required to produce each kilogramme of cod. Higher food conversion ratio was consistent with lower fat content of Nephrops (1.3%) than capelin (9.2%) but the exoskeleton also reduced the digestion rate of Nephrops. In the groups where Nephrops and capelin of equal mean weight were offered simultaneously, 40% of the diet consisted of Nephrops during the first week and 10% during the final seven weeks of the experiment. At the end of the experiment, condition factor, liver index, and gonadosomatic index were significantly lower for cod fed on Nephrops (0.967, 5.7, 7.1, respectively) than for those fed on capelin (1.086, 15.8, 11.2, respectively). These results suggests that predation by cod on Nephrops might be reduced by regular release of capelin or other similar food in the distributional areas of Nephrops.
Organic enrichment and structure of the macrozoobenthic community in the northern Adriatic Sea in an area facing Adige and Po mouths
Authors: Simonini R. , Ansaloni I. , Bonvicini Pagliai A.M. , Prevedelli D. 
Published: September 2004

Abstract
The structure of the macrozoobenthic community and the vertical distribution of organisms in the sediment were studied in order to assess the effects of river outflows and organic enrichment on the benthic community of the North Adriatic Sea. Sampling was carried out at one offshore sandy station (S3) and at two coastal muddy stations (S1 and S2), near to river Po and Adige deltas. Samples were collected in four surveys covering one year from April 1995 to January 1996. In all surveys, the offshore sandy station showed a complex trophic structure, high species richness and diversity, with the occurrence of tubicolous or burrowing polychaetes like Nothria conchylega, Aponuphis bilineata, Maldane sarsi, Nematonereis unicornis and Eunice vittata, which also colonized the deeper sediment layers. On the other hand, the coastal muddy stations both exhibited similar species composition and a great abundance of dominant, opportunistic species such as the bivalve Corbula gibba, typical of unstable sea bottoms with a high rate of sedimentation, and some polychaetes typical of sublittoral muddy bottoms such as Levinsenia gracilis, Aricidea claudiae, Prionospio malmgreni, Sternaspis scutata and P. cirrifera. The high density of a few opportunistic species (mainly surface-deposit feeders) and the scant penetration of organisms within sediments that characterized the stations S1 and S2 support other evidence of the eutrophication of the coastal areas of the north-western Adriatic Sea. However, the high biomass values, the species richness and diversity observed in S1 and S2 suggest the occurrence of less extreme conditions than at other highly-eutrophicated coastal areas. River outflows, eutrophication and, especially, the increasing frequency of acute dystrophic events may be recognized as the driving forces determining the structure and composition of the macrozoobenthic community at coastal areas of north-western Adriatic Sea.
Contrasting years in the Gironde estuary (Bay of Biscay, NE Atlantic) springtime outflow and consequences for zooplankton pyruvate kinase activity and the nutritional condition of anchovy larvae: an early view
Authors: Bergeron Jean-Pierre 
Published: September 2004

AbstractA major spawning ground of the European anchovy (Engraulis encrasicolus) population in the Bay of Biscay is located near the mouth of the Gironde estuary. Variations in the river discharge affect the supply of nutrients to the coastal marine area encompassing anchovy spawning grounds. Two “Pegase” cruises (May–June 1997 and 1998) observed two contrasting situations: with and without a superficial layer of less saline water. Two new nutritional indices were used to assess potential effects (1) on carbohydrate assimilation rates by zooplankton estimated via pyruvate kinase (PK) activity measurements and (2) on nutritional condition of the anchovy larvae measured with the DNA/C index. Both indices indicated a much poorer situation in 1997 compared to 1998. Results of this study implicate river outflow rate as a potential factor influencing larval anchovy condition and perhaps to some extent recruitment variability.
Effects of experimentally‐induced anterior knee pain on knee joint position sense in healthy individuals
Authors: Bennell Kim , Wee Elin , Crossley Kay , Stillman Barry , Hodges Paul 
Published: September 2004

AbstractPurpose. The ability to sense the position of limb segments is a highly specialised proprioceptive function important for control of movement. Abnormal knee proprioception has been found in association with several musculoskeletal pathologies but whether nociceptive stimulation can produce these proprioceptive changes is unclear. This study evaluated the effect of experimentally induced knee pain on knee joint position sense (JPS) in healthy individuals.Study design. Repeated measures, within‐subject design.Methods. Knee JPS was tested in 16 individuals with no history of knee pathology under three experimental conditions: baseline control, a distraction task and knee pain induced by injection of hypertonic saline into the infrapatellar fat pad. Knee JPS was measured using active ipsilateral limb matching responses at 20° and 60° flexion whilst non‐weightbearing (NWB) and 20° flexion single leg stance. During the tasks, the subjective perception of distraction and severity of pain were measured using 11‐point numerical rating scales.Results. Knee JPS was not altered by acute knee pain in any of the positions tested. The distraction task resulted in poorer concentration, greater JPS absolute errors at 20° NWB, and greater variability in errors during the WB tests. There were no significant correlations between levels of pain and changes in JPS errors. Changes in JPS with pain and distraction were inversely related to baseline knee JPS variable error in all test positions (r = −0.56 to −0.91) but less related to baseline absolute error.Conclusion. Knee JPS is reduced by an attention‐demanding task but not by experimentally induced pain. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Endoscopic Treatment of Benign Tumors of the Nose and Paranasal Sinuses
Authors: Pasquini Ernesto , Sciarretta Vittorio , Frank Giorgio , Cantaroni Cosetta , Modugno Giovanni Carlo , Mazzatenta Diego , Farneti Giovanni 
Published: September 2004

OBJECTIVEThe endoscopic approach can be successfully employed for the treatment of benign tumors such as fibroosseus and vascular lesions, pleomorphic adenomas, gliomas, and schwannomas.STUDY DESIGN AND SETTINGNineteen patients diagnosed with benign tumors of the nasal cavity and paranasal sinuses and treated using an endoscopic approach were retrospectively reviewed. The endoscopic approach was used exclusively in 15 cases and was associated with an external approach in 4 cases (due to an intracranial extension of the tumor in 3 patients and its location at the level of the anterior wall of the frontal sinus in the last case).RESULTSThe resection of the lesions was radical in 18 patients and subtotal in 1 case. The mean follow‐up was 27 months and only 1 recurrence (5%) was observed in the juvenile angiofibroma group 20 months postoperatively.CONCLUSION AND SIGNIFICANCEIn selected cases, endoscopic surgery can be considered an effective treatment for the resection of benign tumors involving the sinonasal tract.