Changes In Physical Conditions Research Articles

Evaporation induced self assembly and rheology change during sol-gel coating

Thin films with self-assembled nanostructures are important in applications such as catalysis and biosensor technology. A major technique used to prepare such films is sol-gel processing. This technique involves depositing a complex fluid on a substrate by dip, spin, or spray coating, followed by allowing the film to evaporate and form self-assembled nanostructures. Since the composition of the film during coating is central to understanding how changing chemical and physical conditions affect the properties and microstructures of the films, we investigate the rheological properties of the entrained fluid film and its subsequent impact on the steady state film thickness during the evaporation-induced self-assembly process. We perform systematic experiments to measure the meniscus shape and film thickness during sol-gel dip coating. We observe that the experimental data of film thickness lie way below the Landau-Levich-Derjaguin prediction from the classic film-coating results. To explain this discrepancy, we present a thin film model based on the lubrication approximation with an evaporation effect. Our results show that evaporation-induced self-assembly leads to rheological variations in the entrained film and, consequently, alters the film thickness. The predicted film thickness based on the evaporation-induced rheology variation model compares well with the experiments.

Effects of a compact layer on soil O 2 diffusion

Compact layer in a soil profile may decrease crop yields. One of the major problems is the poor aeration condition within and below the compact layer, resulting in low concentrations of oxygen (O 2) that is needed for root growth. A one-dimensional mathematical model was employed to simulate effects of a compact layer on soil O 2 diffusion within and below this layer under varying soil water and temperature regimes. Changes in physical conditions in the soil were imposed by daily cycles of incident radiation and periods of rainfall. Resulting rates of water infiltration, redistribution, and evaporation as well as concentrations of O 2 as a function of time were obtained. Simulations show that O 2 was depleted much faster in the soil with the compact layer than without this layer. The influence of soil water content near the root tip was also examined. High water content in the compact layer may have a detrimental effect on rhizosphere O 2 concentration and thereby on root growth through the compact layer.

Age-related patterns of reproductive success among female mountain gorillas

A key goal of life history theory is to explain the effects of age and parity on the reproductive success of iteroparous organisms. Age-related patterns may be influenced by changes in maternal experience or physical condition, and they may reflect maternal investment trade-offs between current versus future reproduction. This article examines the influences of age and parity upon the interbirth intervals (IBI), offspring survival, and birth rates of 66 female mountain gorillas in the Virunga Volcano region from 1967-2004. Fertility was relatively low for females below age 12; improved as they matured; and then declined as they aged further. Primiparous mothers had 50% higher offspring mortality and 20% longer IBI than second-time mothers, though only the difference with IBI was statistically significant. The length of subsequent IBI was positively correlated with birth order but not with the mother's age. Mountain gorillas showed no evidence of an extended postreproductive lifespan. Age-related patterns seem most likely to reflect changes in the physical condition of the mother, but more detailed studies are needed to quantify those physical differences, and to obtain behavioral evidence that would provide more direct measures of maternal investment and experience.

Busy Period Analysis of a Man-machine System Operating Subject To Different Physical Conditions

This study deals with some characteristics of a single-unit of a man-machine system operating under different physical conditions. The failure, repair and change of physical conditions (good-poor) are stochastically independent random variables each having an arbitrary distribution. The system analysed by some Markov process technique. The busy period, expected number of visits by the repairman and the cost per unit time in a steady state of the system are obtained. Several important results have been derived as particular cases.

Pronounced occurrence of long-chain alkenones and dinosterol in a 25,000-year lipid molecular fossil record from Lake Titicaca, South America

Our analysis of lipid molecular fossils from a Lake Titicaca (16° S, 69° W) sediment core reveals distinct changes in the ecology of the lake over an ∼25,000-yr period spanning latest Pleistocene to late Holocene time. Previous investigations have shown that over this time period Lake Titicaca was subject to large changes in lake level in response to regional climatic variability. Our results indicate that lake algal populations were greatly affected by the changing physical and chemical conditions in Lake Titicaca. Hydrocarbons are characterized by a combination of odd-numbered, mid- to long-chain (C 21–C 31) normal alkanes and alkenes. During periods when lake level was higher (latest Pleistocene, early Holocene, and late Holocene), the C 21 n-alkane, and the C 25 and C 27 alkenes dominate hydrocarbon distributions and indicate contribution from an algal source, potentially the freshwater alga Botryococcus braunii. The C 30 4 α-methyl sterol (dinosterol) increases sharply during the mid-Holocene, suggesting a greatly increased dinoflagellate presence at that time. Long-chain alkenones (LCAs) become significant during the early Holocene and are highly abundant in mid-Holocene samples. There are relatively few published records of LCA detection in lake sediments but their occurrence is geographically widespread (Antarctica, Asia, Europe, North America). Lake Titicaca represents the first South American lake and the first low-latitude lake in which LCAs have been reported. LCA abundance and distribution may be related to the temperature-dependent response of an unidentified algal precursor. Although the LCA unsaturation indices cannot be used to determine absolute Lake Titicaca temperatures, we suspect that the published LCA U 37 K unsaturation calibrations can be applied to infer relative temperatures for early to mid-Holocene time when LCA concentrations are high. Using these criteria, the U 37 K unsaturation indices suggest relatively warmer temperatures in the mid-Holocene. In contrast to previous speculation, lipid analysis provides little evidence of a greatly increased presence of aquatic plants during the mid-Holocene. Instead, it appears that a few algal species were dominant in the lake. Based on the dramatic rise in abundances of LCAs and dinosterol during the early to mid-Holocene, we suspect that the algal producers of these compounds rose in response to a combination of physical and chemical changes in the lake. These include temperature, salinity, and alkalinity changes that occurred as lake level dropped sharply during a multi-millennial drought affecting the Central Andean Altiplano.

Reintroduction increased vitamin E and condition in captive-bred yellow-footed rock wallabies Petrogale xanthopus

Welfare implications of reintroduction are primarily unknown, although reportedly negative. Few studies have described physiological changes in captive-bred animals post-release and consequently the impact of reintroduction on captive-bred animals is not well understood. Such information is crucial to understanding whether reintroduction constitutes ethical practice. For these reasons two physiological indices associated with animal health, plasma vitamin E concentration (PVEC) or α-Tocopherol, and general condition scores, were monitored in reintroduced captive-bred yellow-footed rock wallabies Petrogale xanthopus celeris and P. x. xanthopus pre- and post-release. PVEC was chosen because deficiencies are common in captive animals compared to their wild counterparts, and have been linked to stress, myopathy, neuronal degeneration, low reproduction, anaemia and death. Changes in physical condition, within this study indicated principally by mass variation, coat condition, and reproductive status, but also parasite load, visible stress, lethargy and diarrhoea, have also not been reported for captive-bred animals reintroduced to the wild. Captive-bred yellow-footed rock wallabies reintroduced to areas of their former range in Queensland and South Australia showed a rapid and sustained increase in PVEC and physical condition, with post-release values significantly higher than pre-release captive levels. Post-release values for both parameters did not significantly differ from that of wild counterparts. Hence I conclude that there was no welfare implications related to the observed parameters in these reintroductions, rather the opposite.

Differences in dynamic response of California Current salmon species to changes in ocean conditions

Abstract While changes in the northeast Pacific Ocean in the mid-1970s apparently caused changes in salmon population growth in the Gulf of Alaska and the California Current, the responses of California Current salmon species, coho salmon (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) differed. Coho salmon catches declined dramatically along the coasts of California, Oregon and Washington, while chinook salmon catches did not. This provides an opportunity for comparative analysis, a rarity in the study of long-term changes in the ocean. Here we test one possible explanation for that difference, that chinook salmon populations are inherently more persistent because chinook salmon populations spawn over a range of ages, while coho salmon spawn predominantly at age 3 yr. We extended a previous theoretical approach that had been used to assess the long-term response of salmon populations with various spawning age structures to different means and variances in environmental variability. New results indicate that populations with environmental variability at the age of return to freshwater have the same characteristic identified earlier for populations with variability in the age of entry: populations spawning at multiple ages are more persistent, but that increased persistence is gained in the first few percent of departure from all spawning at a single age. Thus, in both cases the results are too sensitive to values of uncertain parameters to depend on as an explanation of the differences in response. We also approached this question by subjecting model populations with coho and chinook salmon spawning age structures to an empirical estimate of actual marine survival of coho salmon over the years 1970–2002, asking the question, if chinook salmon had been subjected to the same ocean survivals would they have experienced the same decline. The differences in spawning age structure made little difference in population responses. The dominant factor influencing the response of these species to a decline in ocean survival was the behavior of the freshwater spawner/smolt relationship at low abundance, a factor that has recently been intensively studied for coho salmon, but is poorly known for chinook salmon. These results suggest that the GLOBEC NEP should focus attention on the ocean phase of salmon life, to explain the observed difference in population response to changes in physical conditions.

Climatic effects on the phenology of lake processes

AbstractPopulations living in seasonal environments are exposed to systematic changes in physical conditions that restrict the growth and reproduction of many species to only a short time window of the annual cycle. Several studies have shown that climate changes over the latter part of the 20th century affected the phenology and population dynamics of single species. However, the key limitation to forecasting the effects of changing climate on ecosystems lies in understanding how it will affect interactions among species. We investigated the effects of climatic and biotic drivers on physical and biological lake processes, using a historical dataset of 40 years from Lake Washington, USA, and dynamic time‐series models to explain changes in the phenological patterns among physical and biological components of pelagic ecosystems. Long‐term climate warming and variability because of large‐scale climatic patterns like Pacific decadal oscillation (PDO) and El Niño–southern oscillation (ENSO) extended the duration of the stratification period by 25 days over the last 40 years. This change was due mainly to earlier spring stratification (16 days) and less to later stratification termination in fall (9 days). The phytoplankton spring bloom advanced roughly in parallel to stratification onset and in 2002 it occurred about 19 days earlier than it did in 1962, indicating the tight connection of spring phytoplankton growth to turbulent conditions. In contrast, the timing of the clear‐water phase showed high variability and was mainly driven by biotic factors. Among the zooplankton species, the timing of spring peaks in the rotifer Keratella advanced strongly, whereas Leptodiaptomus and Daphnia showed slight or no changes. These changes have generated a growing time lag between the spring phytoplankton peak and zooplankton peak, which can be especially critical for the cladoceran Daphnia. Water temperature, PDO, and food availability affected the timing of the spring peak in zooplankton. Overall, the impact of PDO on the phenological processes were stronger compared with ENSO. Our results highlight that climate affects physical and biological processes differently, which can interrupt energy flow among trophic levels, making ecosystem responses to climate change difficult to forecast.

Risk assessment of NSAID-induced gastrointestinal toxicity in ambulatory care patients.

The risk of gastrointestinal (GI) toxicity associated with the use of a traditional nonsteroidal antiinflammatory drug (NSAID) versus a cyclooxygenase-2 (COX-2) inhibitor was compared among patients in a managed care organization. Patients over 18 years old who received a prescription for ibuprofen, naproxen, celecoxib, or rofecoxib between March 2001 and June 2001 were included in this study. All subjects were followed for 12 months for GI complications, medication use, and changes in physical conditions from baseline. A simplified risk-scoring scale was used to measure patients' risk of GI complications. A total of 172 patients were randomly selected: 86 receiving traditional NSAIDs and 86 receiving COX-2 inhibitors. Patients receiving COX-2 inhibitors were older and more likely to be receiving treatment for osteoarthritis (OA) or rheumatoid arthritis (RA), while patients taking traditional NSAIDs were more likely to be receiving treatment for acute pain. The average risk scores for patients receiving traditional NSAIDs and COX-2 inhibitors were 0.23% and 0.36%, respectively (p = 0.11). When stratified by indication, there was a significant difference in the risk score for acute pain (p = 0.02) but not for OA, RA, or chronic pain. No GI adverse effects occurred in either group. Among patients in a managed care organization who were taking NSAIDs, most were at low risk for an NSAID-related GI adverse effect. The risk of GI adverse effects did not differ significantly between patients treated with a traditional NSAID and those treated with a COX-2 inhibitor.

The Production of Hiin Photodissociation Regions and a Comparison with CO (1–0) Emission

The gas at the surfaces of molecular clouds in galaxies is heated and dissociated by photons from young stars both near and far. HI resulting from the dissociation of molecular hydrogen H2 emits hyperfine line emission at 21 cm, and warmed CO emits dipole rotational lines such as the 2.6 mm line of CO(1-0). We use previously developed models for photodissociation regions (PDRs) to compute the intensities of these HI and CO(1-0) lines as a function of the total volume density n in the cloud and the far ultraviolet flux G0 incident upon it and present the results in units familiar to observers. The intensities of these two lines behave differently with changing physical conditions in the PDR, and, taken together, the two lines can provide a ground-based radio astronomy diagnostic for determining n and G0 separately in distant molecular clouds. This diagnostic is particularly useful in the range Gzero <~ 100, 10 cm^{-3} <~ n <~ 10^5 cm^{-3}, which applies to a large fraction of the volume of the interstellar medium in galaxies. If the molecular cloud is located near discrete sources of far-UV (FUV) emission, the PDR-generated HI and CO(1-0) emission on the cloud surface can be more easily identified, appearing as layered ``blankets'' or ``blisters'' on the side of the cloud nearest to the FUV source. As an illustration, we consider the Galactic object G216 -2.5, i.e. ``Maddalena's Cloud'', which has been previously identified as a large PDR in the Galaxy. We determine that this cloud has n ~ 200 cm^{-3}, G0 ~ 0.8, consistent with other data.

Residents with dementia in assisted living facilities. The role of behavior in discharge decisions.

The purpose of this exploratory qualitative study was to identify behaviors that contribute to the decision to discharge the resident with dementia from an assisted living facility to a skilled nursing facility. Administrators of 14 assisted living facilities in Missouri were interviewed. The administrators were asked to describe occasions when residents with dementia were discharged. The findings of the study were based on analysis of the audiotapes of the interviews. According to the administrators, resident behaviors that influenced discharge decisions included behaviors indicating progression of dementia, behaviors indicating the need for more assistance with activities of daily living, incontinence, wandering, behaviors that did not meet the facility's expectations, behaviors reflecting changes in physical condition, and aggressive behaviors. These findings have implications for the role of nurses in assisted living facilities and for further research.

PHYSICAL CHANGES DURING COFFEE ROASTING IN ROTARY CONDUCTION‐TYPE HEATING UNITS

ABSTRACTCoffee beans were roasted in a rotary conduction‐type‐heating unit under constant heating surface or product temperatures ranging from 200 to 240C or 170 to 210C, respectively. the roasting duration was varied from 0 to 70 min through intermittent sampling of coffee beans at selected intervals. There were marked changes in physical conditions of coffee beans during roasting. the specific gravity, bulk density, susceptibility to breakage, and color lightness index L changed from 1.2 to 0.5, 0.7 to 0.3 g/cm3, 20 to 100, and 50 to 12, respectively.

THE HEALTH IMPACT OF AN ENERGY EFFICIENCY PROGRAMME FOR ENGLAND

Background The Warm Front programme is a major energy efficiency initiative for England targeted at low income households. Its objective is to reduce fuel use and to improve indoor temperatures ‘to ensure that the most vulnerable households need no longer risk ill-health due to a cold home’. The health impacts of this programme have been the focus of a national evaluation over the winters of 2001–02 and 2002–03. Design Survey of dwellings in the scheme before and after energy efficiency improvements (new heating systems and/or other energy efficiency measures, including insulation and draught-proofing). It was focussed on households containing (a) family members over 60 years of age or (b) children < 16 years. Setting Dwellings in five geographical areas of England Methods Changes in physical conditions and health were measured in around 1100 pre-improvement and a similar number of post-improvement dwellings. Physical conditions, fuel use and energy ratings were assessed by trained surveyors. Indoor temperatures and relative humidity were recorded every 30 minutes over three week periods using data loggers. Thermal comfort, mental well being and health-related quality of life were assessed using standard instruments (Short Form, General Health Questionnaire, EQ5D) and contacts with the health service by questionnaire. In-depth interviews were also carried out in a sample of homes to gather information about changes in behaviours, and epidemiological modelling was used to estimate the impacts of the programme on mortality and hospital admissions. Cross-sectional comparisons were made between the pre- and post-improvement dwellings within each winter, and before-after comparisons were made of the pre-improvement dwellings from the winter of 2001–02 that were assessed again after improvement in 2002–03. Results Although the main results of the evaluation will not be available until autumn 2003, initial indications are that Warm Front improvements lead to appreciable improvement in energy efficiency, modest increases in indoor temperatures, substantial improvement in thermal comfort and significant benefits to quality of life. Epidemiological modelling also suggests modest but important reductions in cold-related mortality. The magnitude of these benefits is related to the type of improvement carried out and the type of households targeted. Conclusions The results to date suggest that energy efficiency improvement can be accompanied by appreciable benefits to health especially when targeted at vulnerable groups. We suggest that the evaluation of this scheme holds valuable lessons for improving population health through measures that also contribute to more sustainable lifestyles.

From Molecular Cores to Planet‐forming Disks: An SIRTF Legacy Program

ABSTRACTCrucial steps in the formation of stars and planets can be studied only at mid‐ to far‐infrared wavelengths, where the Space Infrared Telescope (SIRTF) provides an unprecedented improvement in sensitivity. We will use all three SIRTF instruments (Infrared Array Camera [IRAC], Multiband Imaging Photometer for SIRTF [MIPS], and Infrared Spectrograph [IRS]) to observe sources that span the evolutionary sequence from molecular cores to protoplanetary disks, encompassing a wide range of cloud masses, stellar masses, and star‐forming environments. In addition to targeting about 150 known compact cores, we will survey with IRAC and MIPS (3.6–70 μm) the entire areas of five of the nearest large molecular clouds for new candidate protostars and substellar objects as faint as 0.001 solar luminosities. We will also observe with IRAC and MIPS about 190 systems likely to be in the early stages of planetary system formation (ages up to about 10 Myr), probing the evolution of the circumstellar dust, the raw material for planetary cores. Candidate planet‐forming disks as small as 0.1 lunar masses will be detectable. Spectroscopy with IRS of new objects found in the surveys and of a select group of known objects will add vital information on the changing chemical and physical conditions in the disks and envelopes. The resulting data products will include catalogs of thousands of previously unknown sources, multiwavelength maps of about 20 deg2 of molecular clouds, photometry of about 190 known young stars, spectra of at least 170 sources, ancillary data from ground‐based telescopes, and new tools for analysis and modeling. These products will constitute the foundations for many follow‐up studies with ground‐based telescopes, as well as with SIRTF itself and other space missions such as SIM, JWST, Herschel, and TPF/Darwin.

Indices to estimate fat depots in American marten Martes americana

The relationships between fat depots and body fat content and between protein content and protein indices were examined in American marten Martes americana carcasses obtained from trappers in northeastern Ontario during the 1995/96 fur harvest season. Percent fat and percent protein did not differ significantly between sexes (t = 0.45 and 0.55, P = 0.66 and 0.58, respectively). Protein contents did not vary much among 42 individuals (range: 14–19%), and therefore we found no significant index of percent protein (0.01 &lt; r &lt; 0.23, P &gt; 0.05, N = 42). In the development phase, percent fat (PFAT) was better predicted by six of the eight potential fat indices, and better predicted in females than in males (N = 17 and 18, respectively), but the omentum dry mass (ODM) performed best with both sexes (r2 = 0.69 and 0.80 males and females, respectively). During the test phase (N = 18 males, 22 females), estimated PFAT based on ODM (per sex) did not differ from observed percent fat in either males or in females (paired t = 0.01 and 1.28; P = 0.99 and 0.22, respectively). The models slightly overestimated the number of males and females of below average condition, which indicates that the models were conservative. The accuracy of the omentum dry mass fat depot appears adequate to detect changes of physical condition in harvested marten populations. The lack of variation in protein contents 1) indicates that most animals were near average protein level, possibly due to suitable habitat conditions and 2) prevented us from finding a protein index. We encourage the development of models where conditions (e.g. temperature regime, level of disturbance, carrying capacity) may be harsher for marten.

Present status of submerged macrophyte growth in Lake Biwa: Recent recovery following a summer decline in the water level

AbstractWhole‐lake areal distribution of submerged macrophyte growth in Lake Biwa was surveyed using aerial photographs in 1994 and 2000, when unusual declines in the water level of approximately 1 m occurred in the dry summers. The estimated total areas of the submerged macrophyte communities were 1441 ha for 1994 and 2825 ha for 2000. In the shallow and eutrophic southern basin, the bottom area covered by vegetation gradually increased year by year after 1994, and the ratio of this area to the total surface area of the basin in 2000 amounted to 52%. The dominant species were two natives,Hydrilla verticillataandMyriophyllum spicatum, and one exotic,Egeria densa. Changes in physical conditions and water quality associated with the decline in the water level, as well as the reactions of submerged plants to aquatic environments and ecosystem dynamics, are discussed.

Reflectance of Natural Vegetation of Western Rajasthan Region in Visible and Near-infrared Spectra

This paper presents the study of spectral characteristics of natural vegetation of Western Rajasthan region in the visible and the near-infrared regions of the electromagnetic spectrum. The leaves of ten species of natural vegetation normally grow in Western Rajasthan were evaluated for their spectral reflectance in the wavelength range 400-900 nm under normal laboratory conditions. The change in reflectance due to change in physical condition of plants because of wilting has been observed for three consecutive days. To observe the change due to climatic conditions, the measurements have been carried out in two different seasons. The study aims to undertake design of colour schemes for camouflage painting of various military objects.

Geology of El Misti volcano near the city of Arequipa, Peru

Approximately 750 000 people live at risk in the city of Arequipa, whose center lies 17 km from the summit (5820 masl [meters above sea level]) of the active El Misti volcano. The composite edifice comprises a stratovolcano designated Misti 1 (ca. 833– 112 ka), partially overlapped by two stratocones designated Misti 2 and Misti 3 (112 ka and younger), and a summit cone Misti 4 (11 ka and younger). Eight groups of lava flows and pyroclastic deposits indicate the following volcanic history. (1) Three cones have been built up since ca. 112 ka at an average eruptive rate of 0.63 km3/k.y. (2) Several episodes of growth and destruction of andesitic and dacitic domes triggered dome-collapse avalanches and block-and-ash-flows. Deposition of these flows alternated with explosive events, which produced pyroclastic-flow deposits and tephra-fall and surge deposits. (3) Nonwelded, dacitic ignimbrites may reflect the formation of a 6 × 5 km incremental caldera collapse on Misti 2 (ca. 50 000 and 40 000 yr B.P.) and a 2 × 1.5 km summit caldera on Misti 3 (ca. 13 700 to 11 300 yr B.P.). (4) Tens of pyroclastic flows and at least 20 tephra falls were produced by Vulcanian and sub-Plinian eruptions since ca. 50 ka. On average, ash falls have occurred every 500 to 1500 yr, and pumice falls, every 2000 to 4000 yr. (5) Misti erupted relatively homogeneous andesites and dacites with a few rhyolites, but Misti 4 reveals a distinct mineral suite. Less evolved andesites prevail in scoriaceous products of group 4–1 including historical ash falls. Scoriae of Misti 4 and the ca. 2300–2050 yr B.P. banded pumice commonly show heterogeneous textures of andesite and rhyolite composition. This heterogeneity may reflect changes in physical conditions and magma mixing in the reservoir. (6) Deposits emplaced during the Vulcanian A.D. 1440– 1470 event and the sub-Plinian eruption(s) at ca. 2050 yr B.P. are portrayed on one map. The extent and volume of these deposits indicate that future eruptions of El Misti, even if moderate in magnitude, will entail considerable hazards to the densely populated area of Arequipa.

Assessing Earth‐Moving Operation Capacity by Neural Network‐Based Simulation with Physical Factors

The traditional deterministic method for estimating the production capacity of an earth‐moving operation assumes constant midpoint physical job conditions. In contrast generic simulation models use input of task times without linking production directly to physical factors. This paper presents a microlevel simulation approach, based on thorough evaluation of the effects of changing physical conditions on task times and production, and uses a typical excavation and hauling operation for illustration. Trained neural networks are employed as the computing mechanism for determining equipment cycle times and optimizing the work zone of the excavator. The obtained times are fed directly into a simulation process to establish the cumulative production rate as the achievable operation capacity. Object‐oriented programming is suggested for implementing the solution procedures. The results for two models of excavators in various job conditions are compared with the deterministic estimates.

The impact on musculoskeletal disorders of changing physical and psychosocial work environment conditions in the automobile industry

In the car-body-sealing department at an automobile assembly plant in Sweden, a reorganisation of work from lineout to line production was performed. The aim of the present investigation was to study the influence of changes in physical and psychosocial conditions on musculoskeletal disorders. Working conditions were studied on two occasions, before and after the change. Physical workload regarding strenuous postures and movements was assessed by questionnaires, direct measurements recordings and by computer based observations registrations, and the psychosocial conditions by questionnaires and group discussions. The musculoskeletal disorders of the workers were studied by reports from the occupational health care centre and by self-reported musculoskeletal symptoms. A decrease in the time spent in strenuous positions was found, but the work cycle time decreased considerably and the worker felt ‘robotised’. There was a marked decrease in the perception of opportunities to influence the work, as well as the stimulation at work. The amount of musculoskeletal disorders increased for the study group, but not for a reference group from the same plant. A possible explanation for the increase in musculoskeletal disorders was the increase in perceived physical exertion and the decrease in occupational pride. Relevance to industry This paper illustrates the importance of paying attention to psychosocial issues in order to avoid musculoskeletal disorders after an intervention mainly aimed at physical workstation design.