| 1. |
- Hamberg, Jern, et al.
(författare)
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Stretchability of the rectus femoris muscle: investigation of validity and intratester reliability of two methods including x-ray analysis of pelvic tilt.
- 1993
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Ingår i: Archives of Physical Medicine and Rehabilitation. - 0003-9993 .- 1532-821X. ; 74:3, s. 263-270
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Tidskriftsartikel (refereegranskat)abstract
- Validity and intratester reliability of two test methods designed to identify stretchability of the rectus femoris muscle (RFM) was investigated, combined with x-ray analysis of pelvic tilt in the sagittal plane. The first method is commonly used in clinical practice. The second is a new technique supposed to tilt the pelvis posteriorly and thus further separate the origin and insertion of the muscle. Investigation of validity and intratester reliability of the two methods was made by testing and retesting a random sample of 71 persons. The tests were performed with an equipment that automatically recorded the angle of knee flexion from a previously determined applied torque, indicating the end point of motion for that particular subject. Angle of knee flexion and subjective estimation of pain sensation due to stretch were recorded at each measurement. The pelvic tilt-analysis consisted of test-retest reliability of x-ray measurements, comparison between the methods in both starting and final position, and x-ray and electronic goniometer measurements. All applied torques were measured with a strain gauge. Two out of three criteria of validity favored the new method and the third pointed out the two methods as equal. The two methods as well as the x-ray measurements showed high reliability, and the hypothesis of a more posterior tilted pelvis in the new method was confirmed. The electronic goniometer was less sensitive than x-ray, but proposed to analyse pelvic tilt clinically. Methodology procedures for joint angle measurements are discussed.
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| 2. |
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| 3. |
- Wiklund, Maria Lennernäs, et al.
(författare)
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A new approach for evaluation of meal quality and meal patterns
- 1993
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Ingår i: Journal of human nutrition and dietetics (Print). - 0952-3871 .- 1365-277X. ; 6:3, s. 261-273
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Tidskriftsartikel (refereegranskat)abstract
- An objective, nutritionally orientated classification system is necessary to evaluate the frequency, nutritional quality and temporal distribution of eating events in dietary surveys. In this paper a system to classify eating events qualitatively with regard to the types of food items consumed is described and demonstrated. It comprises eight food categories and criteria for their combination into four types of meals and three types of snacks of various nutrient composition. The food categories represent food items of animal and plant origin, and also food products containing sucrose and beverages containing alcohol or lacking energy and nutrients. Classification requires individual data collected by established food-record or recall methods. Data on consumed amounts is not required to classify qualitatively the eating events per se, but is required for quantitative calculations of their content, composition and relative contribution to total intakes. The application of the system to dietary data (80 repeated 24-h recalls, 517 eating events) of 16 male three-shift workers showed that classification of eating events was easy and largely unequivocal compared to traditional methods. Subsequent calculations showed expected differences between eating types with regard to content and relative quality. The meal-classification system might be used as a cost-effective method to evaluate the nutritional profile of meal patterns in surveys.
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| 4. |
- Wiklund, Maria Lennernäs, et al.
(författare)
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Nocturnal eating and serum cholesterol of three-shift workers
- 1994
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 20:6, s. 401-406
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES - The goal of this study was to examine the effect of rotating three-shift work on the circadian distribution of dietary intake and to investigate the relationships between displaced eating and nutritional status variables [blood lipids, blood glucose, body mass index (BMI)]. METHODS - Dietary data were collected by 147 replicate 24-h dietary recalls from 22 male industrial workers in rotating three-shift work. The intakes of energy and nutrients were estimated by the use of a nutrient data base. The BMI was calculated, and blood glucose, serum triglycerides, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol were measured once. RESULTS - The dietary intakes of energy, protein, total fat, saturated fat, total carbohydrates, sucrose, and dietary fibre did not differ between 24-h periods but did differ between work shifts and were lowest during the night. Correlation analyses between dietary intakes and nutritional status parameters showed that those who redistributed their eating most to the night shift had higher levels of serum total cholesterol and LDL and a higher LDL:HDL ratio; 63% of the LDL cholesterol level was explained by carbohydrate intake during night shifts. In contrast, the total intake for whole 24-h periods or across entire shift cycles was not related to serum variables or BMI. CONCLUSIONS - Dietary intake is lower during night shifts (34-37% of 24-h intake of various nutrients) than during morning shifts (43-47%) and afternoon shifts (47-59%). The redistribution of food intake to the night may be associated with metabolic disturbances in lipid metabolism.
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| 5. |
- Wiklund, Maria Lennernäs, et al.
(författare)
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Nutrient intake in day workers and shift workers
- 1994
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Ingår i: Work & Stress. - : Informa UK Limited. - 0267-8373 .- 1464-5335. ; 8:4, s. 332-342
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Tidskriftsartikel (refereegranskat)abstract
- The 24-h dietary intake, nutritional status parameters and psychosomatic factors of two-shift, three-shift and day workers were compared. Estimations of the dietary intake (across a work cycle) were made by use of a nutrient database. No significant differences were found between the groups for a large number of nutritional variables: intake of energy; intake and percentage of energy from protein, fat, total carbohydrates and sucrose; intake of coffee; and intake and density of vitamins and minerals. Only minor differences were found between the groups with regard to the quantitative intake of alcohol and calcium, and with regard to the quality of the diet (percentage of energy from alcohol, density of calcium). The groups differed significantly with respect to attitude towards work hours (three-shift workers being most negative in their attitude) and sleep disturbances (shift workers being most negative). The three-shift workers were more evening-oriented and they had higher concentrations of glucose in their blood. It was concluded that work hours not related to nutritional intake-at least not when total amounts across time are considered. It was also concluded that work hours were not related to Body Mass Index or blood lipids: triglycerides, total cholesterol, LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol
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| 6. |
- Wiklund, Maria Lennernäs, et al.
(författare)
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Nutrition and 3-shift work : the 24-hour intake of energy and nutrients
- 1994
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Ingår i: Ecology of Food and Nutrition. - : Informa UK Limited. - 0367-0244 .- 1543-5237. ; 32:3-4, s. 157-165
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Tidskriftsartikel (refereegranskat)abstract
- Food consumption was studied (repeated 24-hour recalls) during five days (four different work shifts and days off) in 16 healthy Swedish male papermill workers (rotating 3-shift). A comparison (energy, fourteen nutrients) between 24-hr periods showed a higher intake of energy and five nutrients during the 12 h work shift day compared to days off. The mean 24-hr energy-intake varied between 16,7 MJ (12 h work shift) and 13,3 MJ (days off). When only work hours were considered, the intake of energy and six nutrients were significantly higher during the morning-shift compared to the night-shift. There were no differences in the quality of the diet or the coffee consumption between 24-hr days or between 8-hr shifts. It was concluded that shift work affects 24 h nutrient intake to a very limited extent, although the distribution within 24 hours may vary.
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| 7. |
- Baird, John C., et al.
(författare)
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Stimulus Sequence and the Exponent of the Power Function for Loudness
- 1991
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Ingår i: Perceptual and Motor Skills. - : SAGE Publications. - 0031-5125 .- 1558-688X. ; 73:1, s. 3-17
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Tidskriftsartikel (refereegranskat)abstract
- In two experiments, 15 and 13 subjects estimated the loudness of 12 sound-pressure levels (38–104 dB; 6-dB intervals) of a 1000-Hz tone by the method of magnitude estimation with a modulus assigned to the first stimulus presented. The tone duration was 1 sec. and the interstimulus interval was 6 sec. The presentation order was systematically ascending-descending in one experiment and balanced-irregular in the other. The results indicate that (1) loudness is a power function of sound pressure with an exponent of 0.60 for the systematic order and 0.29 for the irregular order. (2) For both the irregular and systematic orders, a large step-size (12 or 18 dB) between the stimulus on Trial n and on Trial n-1 (or n-3) results in a slight assimilation effect. This also occurs for the small step-size (6 dB) in the irregular order. (3) The size of momentary exponents (based on two points, Trials n and n-l or n-3) depends on the sound pressures of successive stimuli, whether the steps are positive or negative, and whether the stimuli have been presented in systematic or irregular order. For positive steps, the momentary exponent is lower for a soft tone (Trial n) than for a loud tone, whereas for negative steps the momentary exponent is lower for a loud tone than for a soft tone. These effects are more pronounced when these stimuli are presented in an irregular order. A relative judgment model is offered for magnitude estimation. It assumes that subjects judge the loudness of a stimulus in terms of three reference markers: the minimum and maximum sound pressures as well as the sound pressure of the previous stimulus.
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| 8. |
- Björling, Mikael, et al.
(författare)
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Conformational adaption of poly(ethylene oxide). A 13C NMR study
- 1991
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Ingår i: Journal of Physical Chemistry. - 0022-3654. ; 95:17, s. 6706-6709
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Tidskriftsartikel (refereegranskat)abstract
- The 13C NMR chemical shift was used as a probe for the average partition of rotational conformers around the C-C bond in the O-CH2-CH2-O segments of polyethylene oxide). Dividing the conformers into a large group of trans and a smaller group of gauche conformers, we concluded that the trans conformers have a higher (downfield) average chemical shift than the gauche conformers. The shift of the main PEO 13C line with changing environment was interpreted as an adaption in the partition between the two groups of conformers. Furthermore, the trans conformers had nonpolar character and were favored at high temperatures, whereas the gauche conformers had polar character. The measurements were compared to the predictions of a model proposed by Karlström, and a semiquantitative agreement was found.
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| 9. |
- Björling, Mikael, et al.
(författare)
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Distribution of segments for terminally attached poly(ethylene oxide) chains
- 1990
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Ingår i: Journal of Physical Chemistry. - 0022-3654. ; 94:1, s. 471-481
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Tidskriftsartikel (refereegranskat)abstract
- A theory for describing the equilibrium ethylene oxide (EO) segment distribution for terminally attached poly(ethylene oxide) (PEO) chains is presented. It is based on Scheutjens and Fleer's lattice model for polymer solutions in heterogeneous systems and a two-state model for the EO segments. The two-state model provides one explanation of the solubility gap of homogeneous PEO solutions. The segment distribution is examined as a function of temperature, grafting density, and curvature. The present theory predicts distributions, which cannot be reproduced with the use of temperature-dependent interaction parameters in a one-state model. Specifically, the segments tend to be more accumulated at the surface but also far away from the surface at the expense of the intervening transition region. Calculation on a model of a micelles formed by the nonionic surfactant C 12E 8 supports the experimental conclusions that the EO segments are preferentially accumulated nearby the hydrocarbon core and not completely extended into the water region.
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| 10. |
- Björling, Mikael
(författare)
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Interaction between Surfaces with Attached Poly(ethylene oxide) Chains
- 1992
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 25:15, s. 3956-3970
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents a self-consistent mean-field lattice theory of the Scheutjens-Fleer type where segments may adapt to temperature and the local environment by changing their distribution among internal states. Some new features are introduced in the theoretical treatment of incompressible systems, and it is demonstrated how the chemical potential may be calculated without reference to a bulk system. The theory is applied to make a qualitative prediction for the interaction between surfaces with grafted poly-(ethylene oxide), or PEO, chains. A simple two-state model for the PEO segments is used. The attractive force between the PEO-covered surfaces in water is predicted to be related to the temperature-dependent solubility of PEO in water. The contributions to the force are illustrated by simple examples. The attractive force does not change monotonically upon changing the graft density. At low coverages a strong bridging attraction is predicted if the surfaces are hydrophobic. As the surfaces become more polar, repulsion sets in at a larger separation and the overall attraction becomes less strong. A calculated, closed, solubility gap for a crude model of micelles of nonionic surfactants is presented.
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