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Self-reinforced poly(ethylene terephthalate) laminates were prepared from woven fabric by compression moulding. The fabric was stretched to different degrees during heating before hot consolidation to simulate a manufacturing process where the material is stretched through forming. High tenacity poly(ethylene terephthalate) fibres with different degrees of stretching were prepared for a comparison to laminates. Tensile tests were made to characterize mechanical properties, while dynamical mechanical analysis, differential scanning calorimetry, FTIR spectroscopy and X-ray diffraction analysis were employed to study microstructural changes caused by the stretching. Tensile tests show that 13% stretching of the fabric increases the laminate tensile stiffness by 34%. However, same degree of stretching for pure fibres increases the fibre tensile stiffness by 111%. Crystallinity and molecular conformations are not influenced by stretching while shrinkage upon heating increases with degree of stretching. Shrinkage is known to be related to disorientation of non-crystalline regions whereof the conclusion from this study is that the increased tensile properties are due to orientation of the non-crystalline regions of the fibre.

In post-liberalised India, the vast population is regarded as an enormous resource to be exploited as labourers, consumers or for their knowledge. A feature of the new media economy is that newspapers, mobile phones and TV shows are not exclusively produced for the better-off among an urban middle class and, furthermore, that the mass media are increasingly making use of ‘common people’ and their lives in a multitude of places as media content. The subject of this article is whether or not this obsession with the population should be urging us to rethink the Indian media landscape in analytical terms. ‘A public’, Michael Warner argues, is a reflexive relation among strangers, constituted by attention. If the Indian population is now addressed in various new ways, is it time to reconsider the old ‘truth’ that India is an unfit case for discussions about publics?

Background Time-resolved three-dimensional, three-directional phase-contrast magnetic resonance velocity mapping (4D PC-MRI) is a powerful technique to depict dynamic blood flow patterns in the human body. However, the impact of phase background effects on flow visualizations has not been thoroughly studied previously, and it has not yet been experimentally demonstrated to what degree phase offsets affect flow visualizations and create errors such as inaccurate particle traces. Purpose To quantify background phase offsets and their subsequent impact on particle trace visualizations in a 4D PC-MRI sequence. Additionally, we sought to investigate to what degree visualization errors are reduced by background phase correction. Material and Methods A rotating phantom with a known velocity field was used to quantify background phase of 4D PC-MRI sequences accelerated with SENSE as well as different k-t BLAST speed-up factors. The deviation in end positions between particle traces in the measured velocity fields were compared before and after the application of two different phase correction methods. Results Phantom measurements revealed background velocity offsets up to 7 cm/s (7% of velocity encoding sensitivity) in the central slice, increasing with distance from the center. Background offsets remained constant with increasing k-t BLAST speed-up factors. End deviations of up to 5.3 mm (1.8 voxels) in the direction perpendicular to the rotating disc were found between particle traces and the seeding plane of the traces. Phase correction by subtraction of the data from the stationary phantom reduced the average deviation by up to 56%, while correcting the data-set with a first-order polynomial fit to stationary regions decreased average deviation up to 78%. Conclusion Pathline visualizations can be significantly affected by background phase errors, highlighting the importance of dedicated and robust phase correction methods. Our results show that pathline deviation can be substantial if adequate phase background errors are not minimized.

This historical study analyzes the little known practice of gathering food resources from rodent stores in Siberia, with comparative perspectives from northern Europe and North America. Until the 19th century, taking roots, tubers, corms, bulbs, seeds and nuts from rodent food stores was a widespread practice by several ethnic groups in Siberia to supplement their diets. Rodents in northern areas, for example the root vole (Microtus oeconomus), depend on a constant food supply and therefore collect large quantities of plants in their underground caches. Often, but not only during colder seasons, Siberian peoples collected these high-quality plant parts from the voles. Some plundered the stores completely, but others left food or other objects for the animals so that they would survive and gather more the following year. In the circumpolar area ceremonies were held, presenting the rodents with gifts that were valued in human society.

[Review of: ]Shakuntala Banaji, Reading Bollywood: The Young Audience and Hindi Films. Palgrave Macmillan, 2006.

Reactive astrocytes are thought to protect the penumbra during brain ischemia, but direct evidence has been lacking due to the absence of suitable experimental models. Previously, we generated mice deficient in two intermediate filament (IF) proteins, glial fibrillary acidic protein (GFAP) and vimentin, whose upregulation is the hallmark of reactive astrocytes. GFAP−/−Vim−/− mice exhibit attenuated posttraumatic reactive gliosis, improved integration of neural grafts, and posttraumatic regeneration. Seven days after middle cerebral artery (MCA) transection, infarct volume was 210 to 350% higher in GFAP−/−Vim−/− than in wild-type (WT) mice; GFAP−/−, Vim−/− and WT mice had the same infarct volume. Endothelin B receptor (ETBR) immunoreactivity was strong on cultured astrocytes and reactive astrocytes around infarct in WT mice but undetectable in GFAP−/−Vim−/− astrocytes. In WT astrocytes, ETBR colocalized extensively with bundles of IFs. GFAP−/−Vim−/− astrocytes showed attenuated endothelin-3-induced blockage of gap junctions. Total and glutamate transporter-1 (GLT-1)-mediated glutamate transport was lower in GFAP−/−Vim−/− than in WT mice. DNA array analysis and quantitative real-time PCR showed downregulation of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of tissue plasminogen activator. Thus, reactive astrocytes have a protective role in brain ischemia, and the absence of astrocyte IFs is linked to changes in glutamate transport, ETBR-mediated control of gap junctions, and PAI-1 expression.

Purpose: To examine the influence of different doses of gadolinium contrast agent on synovial enhancement, to compare magnetic resonance imaging (MRI) findings of synovial hypertrophy and radiographic joint changes in hemophiliacs, and to investigate the value of gadolinium in MRI assessment of synovial hypertrophy in hemophiliacs using dynamic MRI and MRI scoring. Material and Methods: Twenty-one hemophiliacs on prophylactic factor treatment without recent bleeds were subjected to radiography and gadolinium contrast-enhanced dynamic and static MRI of the knee using a standard dose of 0.1 mmol/kg b.w. gadoteridol. In 17 of the patients, the MRI procedure was repeated after a triple dose of gadoteridol. Results: MRI findings of synovial hypertrophy were significantly correlated with Pettersson radiographic scores. In 19 of the 21 MRI investigated joints, administration of contrast agent did not alter the result of the evaluation of synovial hypertrophy. Conclusion: The optimal time interval for volume assessment of synovial hypertrophy after injection of gadolinium contrast agent is dose dependent. Hemophiliacs without recent bleeds have minor to abundant synovial hypertrophy in joints with pronounced radiographic changes. Dynamic MRI is not useful for evaluating hemophilic arthropathy, and gadolinium contrast agent is not routinely indicated for MRI scoring of joints in hemophiliacs.

Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. Material and Methods: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = K×CBF(DSC). Results: Average whole-brain SPECT CBF was 40.1±6.9 ml/min·100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2±13.8 ml/min·100 g. After correction with the calibration factor, a CBF(ss) of 42.7±14.0 ml/min·100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality ( R = 0.52). Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.

This article concerns journalism as an object of anthropological study. It raises questions about how we should study an occupation that is so familiar in most places of the world. For example, how should we conceptualize newspaper journalism both as a globally diffused media form and as localized cultural practice? Furthermore, I discuss the relationship between the anthropologist and the journalist as two professionals that are equally engaged in producing representations and interpretations of culture and society. The study is based on fieldwork among Hindi-language journalists in Lucknow, India, as well as my own previous experience of local journalism in Sweden

Pension systems and their reforms may have a different impact on men and women because of their different employment histories and demographic characteristics. This paper examines the design of pension systems from a gender perspective. We describe the features of systems and analyse their expected effects on incentives, pension benefits and income distribution for men and women. Empirical results show estimates of the outcomes for men and women in the new Swedish pension system.

Hand-held vibrating tools may result in neuromuscular dysfunction and vasospastic problems of the hand. Sensory and motor dysfunction can be explained by injury to peripheral structures, but could also be due to changes in cortical somatotopic mapping of the hand in the brain. The purpose of the present study was to use functional magnetic resonance imaging (fMRI) to assess the somatotopic cortical representation of the hands of workers subjected to occupational vibration. The study included six men with severe vibration exposures who were suffering from hand–arm-vibration syndrome (HAVS) and six controls. The analysis focused on the pattern and degree of activation of contra- and ipsilateral hemispheres of the brain with tactile stimulation and motor activation of the hand. These stimulations resulted in well-defined activation of the contralateral, and to a lesser extent the ipsilateral hemisphere. Statistical analysis of this limited patient material did not indicate any significant somatotopic cortical changes following long-term exposure to vibrating hand-held tools, although there was a tendency to a shift of activation towards the more cranial parts of the cortex in the patient group.

PURPOSE: The feasibility of hyperpolarized 129Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique.MATERIAL AND METHODS: Hyperpolarized Xe gas was dissolved in ethanol, a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured.RESULTS: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160+/-11 s and T2 approximately 20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70.CONCLUSION: Based on the SNR of the obtained Xe EPI images, it was estimated that rapid in vivo MRA with 129Xe may be feasible, provided that an efficient, biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129Xe. (Less)

Purpose: The feasibility of hyperpolarized 129Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol, a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2≈20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. Conclusion: Based on the SNR of the obtained Xe EPI images, it was estimated that rapid in vivo MRA with 129Xe may be feasible, provided that an efficient, biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129Xe.

Since the early 1990s, there has been no widow's pension in Swedish social insurance. This is consistent with the aim of implementing an individual model, in pursuit of the goal of economic independence for all adults. However, both a widow's and a widower's pension are included in occupational insurance schemes. In Sweden, these are based on collective labour market agreements and cover almost all employees. The survivors' pension can be seen as an annual non-wage benefit. As such, it should be taken into account when remuneration from work between different socio-economic groups is compared. However, we cannot directly observe the individual value of mandatory collective insurance. This article is an original attempt to determine the individual value of certain occupational and social insurance rights. A money value for earnings-related survivors' pension rights is estimated and added to the money wage to create an extended wage measure. We use Swedish microdata to analyze what the inclusion of different insurance rights might mean for wage differentials and wage dispersion. The study indicates that wage inequality is understated when non-wage benefits in the form of survivors' pension rights are excluded from the compensation measure and that a more complete picture of wage differentials is obtained when these rights are accounted for. If we were able to consider differences in survivors' pension rights between countries, this would be a step towards more complete wage comparisons between the different EU-countries.

Purpose: To optimise breath-hold contrast-enhanced MR angiography (MRA) in infants and children with suspected congenital heart or thoracic vessel malformation. Material and Methods: Thirty-nine children (median age 1 year) were examined, using five different ultrafast MRA sequences with a TR between 3.2 and 5.0 ms and the contrast agent meglumine gadoterate. A test injection was used to determine contrast travel time. Different parameters for contrast injection were evaluated. Signal-to-noise ratio (SNR) measurements were performed and image quality and injection timing were evaluated. Results: MRA was successful in all patients and image quality was considered very good in 52%. Adequate SNR was achieved with no significant differences between the MR sequences. SNR decreased only 25-30% between subsequent scans. The mean contrast dose was 0.23 mmol/kg. The mean scan time was 12.5±3.8 s; the shorter scan times made dynamic examinations possible with high temporal resolution. Highest spatial resolution was obtained with TR 4.6/5.0 sequences. Conclusion: A contrast dose of 0.2 mmol/kg b.w. is recommended with an injection rate of 0.5 to 1.2 ml/s, depending on patient size and scan time. The scan delay time should equal the contrast travel time for optimal vessel enhancement. In the future, contrast-enhanced MRA may be a potential alternative to angiocardiography in infants and children.

This article compares public transfers to the elderly and their disposable income in Denmark, Finland, France, Germany, Norway, the Netherlands, Sweden and the U.K. The public transfer income of retirees depends on the particular administrative arrangements in the different countries. The organisation of public pensions varies widely, and yet there is similarity in the overall income situation of older people. Low compensation from the public system is largely made up for by high payments from other systems of compensation, while high compensation from the public system is complemented by other systems of compensation to a lesser extent. It is important to note that this does not mean that the different public pension solutions have the same effect on the distribution of income. The effects of pension systems on income distribution cannot be determined without taking into account what individuals have to pay for their pensions in the form of lower earnings during their active working life. Contributions to the pension system generally mean correspondingly lower cash wages and the design of the pension system affects the size of incomes indirectly by means of its impact on e.g. the labour supply and educational choices. In this article we discuss the direct distributive effects by comparing the relation between the contributions made by individuals and the benefits they receive in different systems and countries. It emerges that the public pension systems in Denmark, the Netherlands and the U.K. redistribute income from higher to lower earners, that the public pension system in Germany does not redistribute income, while the direct redistributive effects of the Swedish, Finnish, French and Norwegian public pension systems are ambiguous and can only be determined through empirical studies.

Purpose: to describe the introduction and performance of proton MR spectroscopy (1H-MRS) in the daily routine of a modern standard MR unit Material and Methods: Over an 8-month period, 52 patients with brain lesions were studied with 1H-MRS, using SE and STEAM sequences for chemical-shift imaging and single-volume spectroscopy. the quality of the spectra was graded from 1 (best) to 3, and the main factors influencing the quality of the spectra were evaluated Results: of the measurements: 85% were graded as 1; 12% as 2; and 3% as 3. the main reasons for poor spectral quality were: the unfortunate positioning of the VOI; hemorrhage; and/or postoperative changes within the VOI. of 40 patients with a final diagnosis: MRS provided an increased confidence in MR diagnosis in 18 cases; MRS contributed significantly to preoperative diagnosis in 3 cases; and the spectra were not specific (n=10) or were difficult to evaluate (n=9) owing to reduced quality (grade 2 or 3) in 19 cases Conclusion: MRS of the brain can provide a high percentage of interpretable spectra and frequently can increase confidence in the MR diagnosis of brain lesions in clinical routine

Purpose: The purpose of this study was to evaluate air enema as a method of assessing acute colitis. Material and Methods: Twenty-seven patients with symptoms of acute colitis underwent plain abdominal radiography, air enema, and colonoscopy within 48 h. The films were evaluated by 3 observers with different levels of experience, both independently and together, and the results were then compared to the findings at endoscopy. Results: Air enema visualized a greater part of the colon than plain abdominal radiography. When air enema was compared to endoscopy as the reference, it showed good correlation, with a positive predictive value of 92% (sensitivity 62%, specificity 85%). Evaluation of the rectum was less accurate, a finding that emphasized the importance of rigid sigmoidoscopy. Conclusion: Air enema is a useful diagnostic method in acute colitis, it is easily performed and tolerated well with no observed complications. It is also easy to interpret, as shown by a high level of agreement (k=0.67) among the 3 independent observers with very different levels of experience.

The fractional volume of capillary blood, i.e. the perfusion fraction f, was measured with the aid of an echo-planar imaging protocol originally designed for the measurement of water diffusion. in healthy volunteers, reasonable f values were obtained. in patients with cerebral ischaemic stroke, a marked decrease in the f value was seen in the infarcted region as compared with corresponding values in the contralateral hemisphere. We suggest that perfusion-fraction measurements may add to the diagnostic value of water-mobility examinations in patients with ischaemic disease

Purpose: To measure blood flow and velocity in the superior sagittal sinus. Material and Methods: MR velocity mapping was used to examine 14 healthy volunteers, 15 patients with normal pressure hydrocephalus (NPH), 3 patients with high pressure hydrocephalus (HPH), and 11 patients with idiopathic intracranial hypertension (IIH). Results: Mean blood flow was 443 ml/min in healthy volunteers with a tendency towards reduced blood flow with increasing age. In NPH patients significantly lower superior sagittal sinus blood flow values were found, but this difference was no longer significant when patients and controls were matched for age. In HPH and IIH patients blood flow and velocity were within the normal range. In one patient with thrombosis of the superior sagittal sinus the blood flow was reduced to 40 ml/min. Conclusion: MR velocity mapping methods may be of value in the assessment of blood flow in the dural sinuses in various pathologies resulting in dural sinus occlusion, such as dural sinus thrombosis, and for following the progress of these patients while undergoing treatment.

Purpose and Material: The aim of this work was, firstly, to compare different manufacturer-provided MRA sequences in a 1.0 T MR unit, with respect to the visibility of an artificial stenosis in a flow phantom and, secondly, to evaluate the same sequences in healthy volunteers with respect to S/N ratio levels and practical in vivo implementation routines. Methods: The studied sequences were 2D and 3D TOF and sequences with an acquisition time of approximately 10 min. Quantitative signal evaluation was made using single transverse partitions in all phantom experiments. MIP angiograms and MPR reconstructions were made for visual inspection of image quality. In vivo, the images were individually evaluated by visual inspection by experienced neuroradiologists. Results: In the evaluation of the grade and length of a stenosis, a combination of MIP and MPR was seen to be the optimal and necessary procedure. A shortening of TE played an important and significant role in the visualization of the poststenotic flow in the phantom using TOF MRA. However, the shortest TE values gave poor S/N ratio in vivo. The good results achieved in the phantom studies for 3D phase-contrast were somewhat reversed in the volunteer studies, whereas 3D TOF sequences showed good results in both the phantom and the volunteer studies.

Deuterium MR spectroscopy was used for the determination of tissue blood flow (TBF). The tracer D2O was injected into the tissue of interest, and tracer washout was followed using a 4.7 T spectroscopy/imaging unit. Normal subcutaneous tissue in rats was studied, as well as tissue influenced by vasoactive agents (papaverine and adrenaline). The vasoactive agents introduced changes of 40% in TBF, compared with normal tissue. Normal tissue measurements were repeated using various D2O injection volumes (5–400 μl). The injection volume 5 μl gave TBF 11.7 ± 2.0 ml/100 g·min (mean ± 1 SD). This value was 40% higher than corresponding values observed at larger injection volumes (200–400 μl). This injection volume effect is probably partly due to a capillary dilution caused by tracer administration, and partly related to the non-physiological deuterium signal decrease observed in dead rats. Blood flow measurements in human colon tumours implanted in nude mice showed a rather poor reproducibility, not improved by the use of a multiple site injection technique.

Deuterium MR spectroscopy was used for the determination of tissue blood flow (TBF). The tracer D2O was injected into the tissue of interest, and tracer washout was followed using a 4.7 T spectroscopy/imaging unit. Normal subcutaneous tissue in rats was studied, as well as tissue influenced by vasoactive agents (papaverine and adrenaline). The vasoactive agents introduced changes of 40% in TBF, compared with normal tissue. Normal tissue measurements were repeated using various D2O injection volumes (5–400 μl). The injection volume 5 μl gave TBF 11.7 ± 2.0 ml/100 g · min (mean ± 1 SD). This value was 40% higher than corresponding values observed at larger injection volumes (200–400 μl). This injection volume effect is probably partly due to a capillary dilution caused by tracer administration, and partly related to the non-physiological deuterium signal decrease observed in dead rats. Blood flow measurements in human colon tumours implanted in nude mice showed a rather poor reproducibility, not improved by...

Using a myocardial tagging technique, normal left ventricular wall motion was studied in 3 true short axis views and a double oblique 4-chamber view in 14 and 11 volunteers, respectively. Three orthogonal directions of left ventricular motion were observed throughout the systole; a concentric contraction towards the center of the left ventricle, a motion of the base of the heart towards the apex, and a rotation of the left ventricle around its long axis. The direction of left ventricular rotation changed from early systole to late systole. The base and middle levels of the left ventricle rotated counterclockwise (CCW) at early systole and clockwise (CW) at late systole, whereas the apex of the heart rotated CW at early systole and CCW at late systole. The different directions of the rotation of base and apex resulted in a myocardial twisting that changed direction from early to late systole. We conclude that MR imaging with myocardial tagging is a method that can be used to study normal left ventricular wall motion, and that is promising for future use in patient groups.

To improve image quality in a vertical field MR imaging unit, operating at low field strength (0.3 T), we have designed a half-elliptical coil for use in the upper thoracic region of small children. Our intention was also to shorten the examination time, which until now has been long, because several scans with different coils have been necessary to cover the thoracic region. The experimental coil is designed so that a child's shoulders fit into the central region. The coil consists of 2 serially connected cable-loops, mounted on a foam rubber vest. The coil performance was tested in a phantom and improvements relative to standard coils were demonstrated in in vivo studies. The results indicate that by using the half-elliptical coil, the signal-to-noise (S/N) ratio can be improved by a factor of 2 to 3 in the thoracic region of a child.

The present work is intended as a nonmathematical review of the role of flow and motion in nuclear magnetic resonance (MR) imaging. A historical review of MR flow measurement techniques is given, followed by a short overview of flow models in vitro and in vivo. The theory behind the influence of motion on the modulus and phase MR signal information is discussed and effects such as washin/washout, flow-induced signal void, phase offset, and phase dispersion are defined. A simple approach to the concept of MR angiography is given, and methods for quantitative flow measurements such as the phase mapping technique, are surveyed. Aspects of the measurement of diffusion and mirocirculation are given, and finally, an overview of the role of MR flow imaging in present and future clinical application is given.

A preliminary investigation of the effects of stimulation of the visual and the motor cortex was made on a conventional 1.5 T MR imaging scanner. Both types of activation gave a detectable change in the signal between rest and stimulation using a gradient echo sequence with an echo time of 60 ms. The observed effects were assumed to be caused by variation in the amount of paramagnetic deoxyhemoglobin between stimulation and rest due to local increase of capillary blood flow in the human brain during stimulation.

A preliminary investigation of the effects of stimulation of the visual and the motor cortex was made on a conventional 1.5 T MR imaging scanner. Both types of activation gave a detectable change in the signal between rest and stimulation using a gradient echo sequence with an echo time of 60 ms. The observed effects were assumed to be caused by variation in the amount of paramagnetic deoxyhemoglobin between stimulation and rest due to local increase of capillary blood flow in the human brain during stimulation.