bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal behaviour of chitosan and chitin thin films studied by spectroscopic ellipsometry
Authors: Montiel‐González Z. , Luna‐Bárcenas G. , Mendoza‐Galván A. 
Published: March 2008

AbstractIn‐situ spectroscopic ellipsometry was used to evaluate the temperature behaviour of chitin and chitosan thin films. For both biopolymers it was found that film thickness decreases with temperature. Two different linear rates were clearly identified by a characteristic temperature Tc, of 51 and 59 °C for chitin and chitosan, respectively. However, the refractive index for chitin decreases with temperature and a more complex behaviour was found for chitosan. The results of this work show that a more complex transformation than water desorption should be claimed to explain the observations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of silicide stacks by combination of spectroscopic ellipsometry and reflectometry
Authors: Fursenko O. , Bolze D. , Costina I. , Zaumseil P. , Huelsmann T. , Niess J. , Lerch W. 
Published: March 2008

AbstractIn this work we show that by combining spectroscopic ellipsometry with reflectometry in the wavelength range from visual to deep ultraviolet the characterization of silicide (NiSi and CoSi2) stacks can be performed by determination of optical constants and thickness of all stack components. Especially, the diagnostic of the surface layer on silicide structures has been performed. By this way non‐destructive monitoring of silicidation process was improved.Additional methods such as X‐ray photoelectron spectroscopy and atomic force microscopy were used to confirm the results. Different impacts of type and thickness of initial metal (Co or Ni), protective cap layer type (Ti or TiN), and rapid thermal process temperature on surface and silicide layers formation were found. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
UV‐induced in‐plane anisotropy in layers of mixture of the azo‐dyes SD‐1/SDA‐2 characterized by spectroscopic ellipsometry
Authors: Valyukh Iryna , Arwin Hans , Chigrinov Vladimir , Valyukh Sergiy 
Published: March 2008

AbstractThe optical properties of the azo‐dyes SD‐1/SDA‐2, which are used for photoaligning of liquid crystals (LCs), are investigated with Variable Angle Spectroscopic Ellipsometry (VASE). Films of mixture of SD‐1/SDA‐2 are deposited by spin coating on silicon wafers. The estimated thickness is approximately 10 nm. To achieve photo‐induced anisotropy, one of the samples is illuminated during 15 minutes with linearly polarized UV light followed by thermal stabilization during 1 hour at 150 °C. VASE measurements are performed in the wavelength range 200–1350 nm at several angles of incidence and at different sample orientations. Dielectric functions of azo‐dye films without/with polarized UV light illumination were modelled using an ensemble of Lorentz oscillators. The results confirm the diffusion model proposed recently for explanation of the formation of the photo‐induced order in azo‐dye films under the action of polarized light. Refractive indices, their wavelength dispersion and thicknesses of films of SD‐1/SDA‐2 are reported here. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Product decomposition of measured Mueller matrices from the FLC based NIR Mueller Matrix Ellipsometer
Authors: Stabo‐Eeg F. , Ladstein J. , Kildemo M. 
Published: March 2008

AbstractThis paper reports on the application of the first near‐infrared spectroscopic Mueller Matrix Ellipsometer (MME) based on Ferro‐electric Liquid Crystal retarders (FLC) and fixed waveplates. Operation of the instrument is demonstrated by transmission Mueller matrix measurements, and product decomposition of an imperfect dichroic polarizer and a depolarizing rough glass surface. The decomposition of the measured matrices is qualtitatively discussed in terms of retardance, diattenuation, depolarization, and azimuthal orientation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast near‐infra‐red spectroscopic Mueller matrix ellipsometer based on ferroelectric liquid crystal retarders
Authors: Ladstein J. , Stabo‐Eeg F. , Garcia‐Caurel E. , Kildemo M. 
Published: March 2008

AbstractThis paper reports on the design and construction of the first near‐infra‐red spectroscopic Mueller Matrix Ellipsometer (MME) based on Ferroelectric Liquid Crystal retarders (FLC) and fixed waveplates. The design was performed by assuming ideal optical polarizing components. In particular, the current FLC‐MME is optimised to operate in the near‐infra‐red (NIR) spectral range from 800 nm to 1800 nm. The FLC based Polarization State Generator (PSG) and Polarization State Analyzer (PSA) have been optimized by keeping the condition number of the PSG's modulation matrix and the PSA's analysis matrix close to an optimum over the spectral design range. The design is realized in a setup using the full Mueller matrix measurement formalism based on the Eigenvalue Calibration Method (ECM). The actual modulation matrix and analysis matrix are obtained from the ECM, and the condition numbers immediately indicates the quality of the design. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined effect of ultraviolet‐B radiation and cadmium contamination on nutrient uptake and photosynthetic pigments in Brassica campestris L. seedlings
Authors: Shukla U. C. , Murthy R. C. , Kakkar P. 
Published: March 2008

AbstractEnvironmental and industrial pollution along with increase in ground level UV‐B radiation, because of stratospheric ozone depletion, present multiple stresses, which may affect crop photosynthesis and productivity. The present study was undertaken to see interactive effects of heavy metal contamination (Cd2+) and UV‐B exposure on essential nutrient (Ca2+, Mg2+, K+) uptake, biomass, and chlorophyll content in mustard (Brassica campestris L.) seedlings. Plants grown in 0.5, 1.0, 2.5, and 5.0 mg L−1 Cd2+ supplemented medium were exposed to UV‐B for 30 min (0.4 mW cm−2) per day. The interactive effect of two stresses measured after 5 and 10 days showed an overall decline in biomass. Under dual stress (5 mg Cd2+ L−1) significant (P < 0.001) decrease in chlorophyll a (43%), chlorophyll b (23%), and carotenoid (53%) was observed. Ca2+ uptake was reduced by 51% in roots under high doses of Cd2+ (5 mg L−1) and simultaneous exposure to 0.4 mW cm−2 UV‐B for 10 days. Mg2+ content was reduced by 48% and K+ by 62% under similar exposure conditions. Decline in nutrient uptake in Brassica campestris L. seedlings was observed both in root and shoot leaf in the initial growth period under controlled lab conditions. Cadmium ion (Cd2+) uptake was significantly enhanced by 33% (P < 0.001) in the presence of UV‐B. The findings are significant as multiple stress conditions prevalent in the environment play an important role during the early growth period, a period critical for crop yield. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Late Presentation of Intestinal Malrotation: An Argument for Elective Repair
Authors: Moldrem Amy W. , Papaconstantinou Harry , Broker Harshal , Megison Steve , Jeyarajah D. Rohan 
Published: March 2008

AbstractBackgroundMidgut malrotation most commonly presents in young children. This diagnosis is not often entertained in the adolescent or adult with abdominal complaints. We reviewed our experience with this subset of malrotation patients.MethodsA retrospective review of medical records from adolescent or adult patients identified with a diagnosis of anomaly of intestinal fixation or malrotation, who were treated within our health system between 1993 and 2004.ResultsA total of 33 patients were diagnosed with malrotation and treated with Ladd’s procedure. Acute abdominal pain was present in 50%, and chronic complaints were present in the other patients. Initial work‐up included computed tomography (CT) scan (28%), upper gastrointestinal (UGI) study (38%), and plain films (47%) Postoperative complications occurred more frequently in patients that were operated on emergently (60%) than in those that underwent elective surgery (22%; p = 0.04).ConclusionsThis large case series of intestinal malrotation in the nonpediatric age group suggests that Ladd’s procedure can be performed very safely. Moreover, the results suggest that patients with known malrotation should have Ladd’s procedure performed electively rather than urgently.
Folate and vitamin B12status in relation to cognitive impairment and anaemia in the setting of voluntary fortification in the UK
Authors: Clarke Robert , Sherliker Paul , Hin Harold , Molloy Anne M. , Nexo Ebba , Ueland Per M. , Emmens Kathleen , Scott John M. , Evans John Grimley 
Published: March 2008

Concerns about risks for older people with vitamin B12deficiency have delayed the introduction of mandatory folic acid fortification in the UK. We examined the risks of anaemia and cognitive impairment in older people with low B12and high folate status in the setting of voluntary fortification in the UK. Data were obtained from two cross-sectional studies (n2403) conducted in Oxford city and Banbury in 1995 and 2003, respectively. Associations (OR and 95 % CI) of cognitive impairment and of anaemia with low B12status (holotranscobalamin < 45 pmol/l) with or without high folate status (defined either as serum folate >30 nmol/l or >60 nmol/l) were estimated after adjustment for age, sex, smoking and study. Mean serum folate levels increased from 15·8 (sd14·7) nmol/l in 1995 to 31·1 (sd26·2) nmol/l in 2003. Serum folate levels were greater than 30 nmol/l in 9 % and greater than 60 nmol/l in 5 %. The association of cognitive impairment with low B12status was unaffected by highv.low folate status (>30 nmol/l) (OR 1·50 (95 % CI 0·91, 2·46)v.1·45 (95 % CI 1·19, 1·76)), respectively. The associations of cognitive impairment with low B12status were also similar using the higher cut-off point of 60 nmol/l for folate status ((OR 2·46; 95 % CI 0·90, 6·71)v.(1·56; 95 % CI 1·30, 1·88)). There was no evidence of modification by high folate status of the associations of low B12with anaemia or cognitive impairment in the setting of voluntary fortification, but periodic surveys are needed to monitor fortification.
Management of temporal bone meningo-encephalocoele
Authors: Ramalingam K K , Ramalingam R , SreenivasaMurthy T M , Chandrakala G R 
Published: March 2008

AbstractMeningo-encephalocoele of the temporal bone, also known as fungus cerebri, is a rare occurrence in clinical practice. We present a series of 13 patients with chronic otitis media who suffered brain herniation into the mastoid cavity. We also discuss the presentation and management of brain herniation with or without cerebrospinal fluid leak.Study design:Retrospective.Methods:Among 963 cases undergoing revision mastoid surgery, 13 patients suffered brain herniation. These cases were identified and analysed.Results:All 13 patients' initial diagnosis was chronic suppurative otitis media with cholesteatoma, and all had undergone previous mastoid surgery resulting in a defect in the tegmen and weakening of the dura mater. The revision procedures performed included 10 (76.9 per cent) modified radical mastoidectomies without ossicular chain reconstruction and one (7.6 per cent) modified radical mastoidectomy with ossicular chain reconstruction; two (15.3 per cent) patients required a blind sac closure. Brain herniation and/or cerebrospinal fluid leak were repaired by a transmastoid ± minicraniotomy procedure.Conclusions:Injury to the tegmen and dura should be avoided during surgery for chronic middle-ear disease. Cerebrospinal fluid leaks, if encountered, should be managed in the same surgical session. The transmastoid approach is helpful in repairing defects smaller than 1 cm in diameter, whereas the combined transmastoid-minicraniotomy approach provides good access when closing defects larger than 1 cm in diameter and also enables auto-calvarial grafting.
Transmission and quantification of verocytotoxin-producingEscherichia coliO157 in dairy cattle and calves
Authors: SCHOUTEN J. M. , GRAAT E. A. M. , FRANKENA K. , VAN ZIJDERVELD F. , DE JONG M. C. M. 
Published: March 2008

SUMMARYData from a field study of 14 months duration in a naturally colonized dairy herd and data from an experiment with calves were used to quantify transmission of verocytotoxin-producingEscherichia coli(VTEC O157) in cattle. For the latter, two groups of 10 calves were randomly assigned and put out in one of two pastures. From each group, five animals were experimentally inoculated with 109c.f.u. O157 VTEC and, considered infectious, put back in their group. Each of the susceptible contact calves became positive within 6 days of being reunited. The estimate of the basic reproduction ratio (R0) in the experiment was 7·3 (95% CI 3·92–11·5), indicating that each infectious calf will infect seven other calves on average during an assumed infectious period of 28 days in a fully susceptible population. TheR0among dairy cows appeared to be about 10 times lower (0·70, 95% CI 0·48–1·04). After the transmission experiment, six contact-infected animals that were shedding continuously during the experiment were housed in a tie stall during winter. After 40 days, all six tested negative for O157 VTEC. In June, after a period of 34 weeks in which the heifers remained negative, they were put out in a clean and isolated pasture to observe whether they started shedding again. On each pasture that was infected with O157 VTEC during the transmission experiment the previous summer, newly purchased susceptible calves were placed. None of the heifers or calves started shedding during 14 weeks, indicating that both the heifers and the previously contaminated pasture did not function as reservoir of O157 VTEC.
Antigen-independent priming: a transitional response of bovine γδ T-cells to infection
Authors: Jutila Mark A. , Holderness Jeff , Graff Jill C. , Hedges Jodi F. 
Published: March 2008

AbstractAnalysis of global gene expression in immune cells has provided unique insights into immune system function and response to infection. Recently, we applied microarray and serial analysis of gene expression (SAGE) techniques to the study of γδ T-cell function in humans and cattle. The intent of this review is to summarize the knowledge gained since our original comprehensive studies of bovine γδ T-cell subsets. More recently, we have characterized the effects of mucosal infection or treatment with microbial products or mitogens on gene expression patterns in sorted γδ and αβ T-cells. These studies provided new insights into the function of bovine γδ T-cells and led to a model in which response to pathogen-associated molecular patterns (PAMPs) induces ‘priming’ of γδ T-cells, resulting in more robust responses to downstream cytokine and/or antigen signals. PAMP primed γδ T-cells are defined by up-regulation of a select number of cytokines, including MIP1α and MIP1β, and by antigens such as surface IL2 receptor α (IL-2Rα) and CD69, in the absence of a prototypic marker for an activated γδ T-cell, IFN-γ. Furthermore, PAMP primed γδ T-cells are more capable of proliferation in response to IL-2 or IL-15 in the absence of antigen. PAMPs such as endotoxin, peptidoglycan and β-glucan are effective γδ T-cell priming agents, but the most potent antigen-independent priming agonists defined to date are condensed oligomeric tannins produced by some plants.
Studies in Spaced and Massed Learning: III. Paired-Associate and Serial Learning
Authors: Tsao J. C. 
Published: March 2008

An experiment on paired-associate learning was carried out to test Hovland's prediction that spaced practice should be more advantageous than massed if the order of presenting the pairs of nonsense syllables were fixed. In the results, spaced and massed practice showed little difference in learning efficiency. Hovland's prediction was not confirmed. In a previous experiment of this series of studies it had been found that spaced practice was more efficient than massed in serial learning when syllables of “low-meaningfulness” value were used; but that there was little difference in efficiency between the two forms of distribution when “high-meaningfulness” syllables were used. The results of the two experiments naturally suggested that, as regards the relative efficiency of spaced and massed practice, paired-associate learning of low-meaningfulness syllables differed from serial learning of similar syllables, but matched serial learning of high-meaningfulness syllables. It seems justifiable to draw the conclusion that the relative efficiency of spaced and massed practice is different in paired-associate and serial learning, not because remote associations can be formed in the one case and not in the other, as Hovland (1939a, 1939b) assumed; but because the organization of the material and the learning processes are different in the two forms of learning.
The Effect of One Experience upon the Recall of Another
Authors: Davis D. Russell , Sinha Durganand 
Published: March 2008

An exploratory experiment was made to show how one experience may exert an influence upon the recall of another, and how both may lose their separate identities in memory, to become merged into what Bartlett has described as an active organization of related experiences. The original material was a story, and the experience interpolated between it and its recall was a picture which illustrated part of it, in some respects correctly, in others incorrectly. Some subjects were asked to recall the story, others the picture, after from one to four weeks, or in a few cases a year. The picture was viewed under the influence of the attitudes induced by the story. These determined its selection from a number of other unrelated pictures, to be perceived as a related experience. In consequence only few details gained attention, and these were interpreted in terms of the attitudes induced by the story, in some cases contrary to the meaning given to them by the rest of the picture. Other details without significance in the theme of the story were neglected. In its turn, seeing the picture favoured the recall of some aspects of the theme of the story, details not reinforced by the picture tending to be left out in recall. Many picture details intruded into the reproductions of the story. This tendency was progressive, and at the end of a year picture and story details were not separated. Especially, the picture brought about changes in the points of emphasis in the story.
Perceptual Anticipation and Reaction Time
Authors: Poulton E. C. 
Published: March 2008

To determine the effect of perceptual anticipation upon reaction time, two different types of experiment were carried out. In the first a skilled response had occasionally to be altered at a given point after a variable warning period. In the second the subject had to react to two auditory signals separated by a short time interval which was systematically varied, the second signal being expected or unexpected. It was found that lack of readiness to respond to a signal, as revealed by a lengthened reaction time, may be due either to the subject not having prepared himself, as he was not expecting the signal; or to the subject not being able to prepare himself in time. Preparation for reacting to the second of the two signals, when both are expected and have to be reacted to, never appears to take more than between 0·2 and 0·4 seconds, as judged by reaction time. On the majority of occasions it appears to be complete in 0·2 seconds. These times are shorter than those usually given, because the extra delay due to incorrect anticipation has been excluded. With intervals of 0·1 seconds or less, delay in the second reaction may be due to the mechanical difficulty of responding quickly enough, especially when the two reactions have to be made in opposite directions. The finding that lack of readiness might be due to the subject not expecting the signal, and the further finding that preparation took longer when a skilled response had to be extended than when it had to be stopped, both suggest that so-called Psychological refractoriness is due to lack of fore period in which to prepare for the response, rather than to a “Psychological refractory phase” comparable to the refractory phase of nerves. If, by dividing his attention, the subject was able to prepare for his next response while making his previous one, so-called Psychological refractoriness could be completely absent.
The Relation between Angle of Display and Performance in a Prolonged Visual Task
Authors: Fraser D. C. 
Published: March 2008

An experiment is described to test the relation between angle of display and performance in prolonged visual tasks, using the Clock Test in three positions of display surface, vertical, at an angle of 45 degrees to the horizontal, and horizontal. In every case the line of regard was kept at right-angles to the display surface. The results indicate that significantly fewer stimuli are missed in the vertical position of the display surface than in the other two. The deterioration observed in the second half-hour of the original Clock Test experiments was not found in the present experiment, and two possible reasons for this are discussed briefly.
The Effects of Repeated Retesting: III. Further Experiments and General Conclusions
Authors: Cane V. R. , Heim A. W. 
Published: March 2008

This is the third of a series of papers dealing with the effects of repeated retesting on intelligence test scores. It comprises an account of two further experiments, and a discussion of the four so far performed, since each throws light on the results of the others and it is their joint interpretation which is thought to be of value. The two earlier experiments consisted in repeated testing of a group of W.E.A. students and a group of mentally defective boys by an intelligence test (AH 4) designed for an unselected population. In the two later experiments, a group of Technical College students and a group of Naval Ratings were repeatedly tested on another intelligence test (AH 5), designed for a population of high-grade intelligence, such as university students. Examination of all the results confirms the artificiality of the “ceiling effect” which was suspected in the first experiment; it suggests that, given sufficient scope, subjects of all levels of intelligence would, with repeated trials on the same test, continue to improve their score up to and beyond 10 testing; and that, given comparable opportunity, subjects with initially higher scores will tend to improve more than those with initially lower scores. All these results concern short-term experiments with testing at weekly intervals. The four sets of results considered jointly indicate that conclusions on these problems should be drawn only in terms of the relation between the level of the test and that of the group tested: this offers some resolution of the conflicting findings of earlier investigators.
On the Rate of Gain of Information
Authors: Hick W. E. 
Published: March 2008

The analytical methods of information theory are applied to the data obtained in certain choice-reaction-time experiments. Two types of experiment were performed: (a) a conventional choice-reaction experiment, with various numbers of alternatives up to ten, and with a negligible proportion of errors, and (b) a ten-choice experiment in which the subjects deliberately reduced their reaction time by allowing themselves various proportions of errors. The principal finding is that the rate of gain of information is, on the average, constant with respect to time, within the duration of one perceptual-motor act, and has a value of the order of five “bits” per second. The distribution of reaction times among the ten stimuli in the second experiment is shown to be related to the objective uncertainty as to which response will be given to each stimulus. The distribution of reaction times among the responses is also related to the same uncertainty. This is further evidence that information is intimately concerned with reaction time. Some possible conceptual models of the process are considered, but tests against the data are inconclusive.