| 1. |
- Franzén, Carl Johan, 1966, et al.
(författare)
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Multifeed simultaneous saccharification and fermentation enables high gravity submerged fermentation of lignocellulose.
- 2015
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Ingår i: Recent Advances in Fermentation Technology (RAFT 11), Clearwater Beach, Florida, USA, November 8-11, 2015. Oral presentation..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Today, second generation bioethanol production is becoming established in production plants across the world. In addition to its intrinsic value, the process can be viewed as a model process for biotechnological conversion of recalcitrant lignocellulosic raw materials to a range of chemicals and other products. So called High Gravity operation, i.e. fermentation at high solids loadings, represents continued development of the process towards higher product concentrations and productivities, and improved energy and water economy. We have employed a systematic, model-driven approach to the design of feeding schemes of solid substrate, active yeast adapted to the actual substrate, and enzymes to fed-batch simultaneous saccharification and co-fermentation (Multifeed SSCF) of steam-pretreated lignocellulosic materials in stirred tank reactors. With this approach, mixing problems were avoided even at water insoluble solids contents of 22%, leading to ethanol concentrations of 56 g/L within 72 hours of SSCF on wheat straw. Similar fermentation performance was verified in 10 m3 demonstration scale using wheat straw, and in lab scale on birch and spruce, using several yeast strains. The yeast was propagated in the liquid fraction obtained by press filtration of the pretreated slurry. Yet, even with such preadaptation and repeated addition of fresh cells, the viability in the SSCF dropped due to interactions between lignocellulose-derived inhibitors, the produced ethanol and the temperature. Decreasing the temperature from 35 to 30°C when the ethanol concentration reached 40-50 g/L resulted in rapid initial hydrolysis, maintained fermentation capacity, lower residual glucose and xylose and ethanol concentrations above 60 g/L.
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| 2. |
- Bergman, Frida, 1984-
(författare)
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Active workstations : a NEAT way to prevent and treat overweight and obesity?
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Modern society is triggering sedentary behaviours in different domains. Different strategies can be used to reduce the time spent sitting and increase physical activity in the office environment, which is one domain where sedentary time is often high. One such strategy could be to install treadmill workstations. With these, the office workers can walk on a treadmill while performing their usual work tasks at the computer. However, the long-term effects of these workstations are not known. Aim: The overall aim of this thesis was to investigate the long-term effects on sedentary behaviour, physical activity and associated health factors of installing treadmill workstations in offices compared to regular office work.Method: In this randomized controlled trial, 80 sedentary, middle-aged, healthy office workers with overweight or obesity were individually randomized into either an intervention or a control group. Those in the intervention group had a treadmill workstation installed at their sit-stand desk, to use for at least one hour per day for 13 months. They further received boosting e-mails at four time-points during the study. Participants in the control group continued to work as normal at their sit-stand office desk. All participants also received a health consultation at the beginning of the study, where they got to discuss physical activity and diet recommendations. Measurements reported include physical activity and sedentary behaviour, anthropometric measurements, body composition, metabolic outcomes, stress, depression and anxiety, cognitive function, structural brain images and interview data. Linear mixed models were used for the main statistical analyses of the quantitative data. An exploratory approach was also undertaken, using orthogonal partial least squares regression on the baseline data. Finally, interview data from participants in the intervention group were analysed using a modified Grounded Theory approach.Results: The intervention group increased their daily walking time and their number of steps at all follow-ups compared to the control group. Concomitantly, a decrease in moderate-to-vigorous intensity physical activity (MVPA) was observed within both groups, mainly during weekends. No intervention effects were observed on any of the body, cognitive or brain volume measurements. Our exploratory analyses revealed a significant association between smaller hippocampal volume and percentage sitting time among participants over 51 years of age. From the interview data, we discovered a core category, “The Capacity to Benefit”. The categories were described as the ideal types the Convinced, the Competitive, the Responsible and the Vacillating, based on the principal characteristics of the participants representing their different motivational status and strategies to reach the goal of benefitting from the intervention. Conclusion: It is possible to increase daily physical activity in office environments by introducing treadmill workstations. Future interventions should adapt strategies for the individuals based on their motivational level, but should also workwith the social and physical environment and with factors within the organization to gain the best effects of these interventions.
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| 3. |
- Bergman, Frida, Medicine doktor, 1984-, et al.
(författare)
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Increasing Physical Activity In Office Workers - An RCT Of Treadmill Workstations
- 2018
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Ingår i: Medicine & Science in Sports & Exercise. - : Lippincott Williams & Wilkins. - 0195-9131 .- 1530-0315. ; 50:5, s. 47-47
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- PURPOSE: Our primary hypothesis was that an intervention with treadmill workstations would increase time spent walking. Secondary hypotheses were a decrease in time spent sitting with a concomitant increase in time spent standing and in light intensity physical activity (LPA) leading to positive effects on body measurements and body composition.METHODS: The intervention group received a treadmill workstation at their office desk during 13 months. Daily time spent sitting, standing and walking and number of steps was measured with activPAL®. Daily time in LPA and MVPA was measured with Actigraph®. Body weight, BMI and waist circumference were measured according to standardized protocols. Dual X-ray Absorptiometry was used to estimate body composition. Mixed models was used for the statistical analysis, with group, day of week (weekday/ weekend), time point and gender as fixed effects and age as a covariate. p<0.05 was considered significant.RESULTS: Eighty participants were included. The intervention group significantly increased their time spent walking at all follow-ups, with a difference at 13 months of 22 minutes (p<0.01) and 1645 steps per day (p<0.05), respectively, versus controls. Concomitantly, they decreased their MVPA with 13 minutes per day (p<0.001) at weekdays at 13 months versus baseline. We also found a decrease in LPA with 19 minutes per day (p<0.05), and of 17 minutes per day for MVPA (p<0.001) at 13 months versus baseline at weekends. The control group increased their time spent sitting with 25 minutes per day (p<0.05) and decreased the time spent standing with 35 minutes per day at weekdays (p<0.001) compared to baseline. There was also a decrease in LPA with 14 minutes per day (p<0.01) and in MVPA with 6 minutes per day (p<0.01) versus baseline during weekdays, with a decrease in sitting time with 36 minutes (p<0.05) at weekends. There were no significant changes in body measurements or body composition.CONCLUSION: It is possible to increase daily walking time by introducing treadmill workstations at offices. A decreased MVPA within the intervention group may contribute to lack of effects on body measurements and body composition. It is therefore important that future interventions aim at both reducing sedentary time as well as increasing, or at least remaining, MVPA levels.
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| 4. |
- Bergman, Frida, 1984-, et al.
(författare)
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Increasing physical activity in officeworkers – the Inphact Treadmill study : a study protocol for a 13-month randomized controlled trial of treadmill workstations
- 2015
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Ingår i: BMC Public Health. - : BioMed Central. - 1471-2458. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sedentary behaviour is an independent risk factor for mortality and morbidity, especially for type 2 diabetes. Since office work is related to long periods that are largely sedentary, it is of major importance to find ways for office workers to engage in light intensity physical activity (LPA). The Inphact Treadmill study aims to investigate the effects of installing treadmill workstations in offices compared to conventional workstations.Methods/Design: A two-arm, 13-month, randomized controlled trial (RCT) will be conducted. Healthy overweight and obese office workers (n = 80) with mainly sedentary tasks will be recruited from office workplaces in Umeå, Sweden. The intervention group will receive a health consultation and a treadmill desk, which they will use for at least one hour per day for 13 months. The control group will receive the same health consultation, but continue to work at their regular workstations. Physical activity and sedentary time during workdays and non-workdays as well as during working and non-working hours on workdays will be measured objectively using accelerometers (Actigraph and activPAL) at baseline and after 2, 6, 10, and 13 months of follow-up. Food intake will be recorded and metabolic and anthropometric variables, body composition, stress, pain, depression, anxiety, cognitive function, and functional magnetic resonance imaging will be measured at 3–5 time points during the study period. Interviews with participants from the intervention group will be performed at the end of the study.Discussion: This will be the first long-term RCT on the effects of treadmill workstations on objectively measured physical activity and sedentary time as well as other body functions and structures/morphology during working and non-working hours among office workers. This will provide further insight on the effects of active workstations on our health and could fill in some of the knowledge gaps regarding how we can reduce sedentary time in office environments.
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| 5. |
- Bergman, Frida, 1984-, et al.
(författare)
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Treadmill workstations in office workers who are overweight or obese : a randomised controlled trial
- 2018
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Ingår i: The Lancet Public Health. - : The Lancet Publishing Group. - 2468-2667. ; 3:11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Treadmill workstations that enable office workers to walk on a treadmill while working at their computers might increase physical activity in offices, but long-term effects are unknown. We therefore investigated whether treadmill workstations in offices increased daily walking time.Methods: We did a randomised controlled trial of healthy office workers who were either overweight or obese. We recruited participants from 13 different companies, which comprised 17 offices, in Umeå, Sweden. We included people who were aged 40-67 years, had sedentary work tasks, and had a body-mass index (BMI) between 25 kg/m2 and 40 kg/m2. After the baseline measurement, we stratified participants by their BMI (25-30 kg/m2 and >30 to 40 kg/m2); subsequently, an external statistician randomly assigned these participants (1:1) to either the intervention group (who received treadmill workstations for optional use) or the control group (who continued to work at their sit-stand desks as usual). Participants in the intervention group received reminders in boosting emails sent out to them at four occasions during the study period. Researchers were masked to group assignment until after analysis of the primary outcome. After the baseline measurement, participants were not masked to group belongings. The primary outcome was total daily walking time at weekdays and weekends, measured at baseline, 2 months, 6 months, 10 months, and 13 months with the accelerometer activPAL (PAL Technologies, Glasgow, UK), which was worn on the thigh of participants for 24 h a day for 7 consecutive days. We used an intention-to-treat approach for our analyses. This trial is registered with ClinicalTrials.gov, number NCT01997970, and is closed to new participants.Findings: Between Nov 1, 2013, and June 30, 2014, a total of 80 participants were recruited and enrolled (n=40 in both the intervention and control groups). Daily walking time during total time awake at weekdays increased between baseline and 13 months by 18 min (95% CI 9 to 26) in the intervention group and 1 min (-7 to 9) in the control group (difference 22 min [95% CI 7 to 37], pinteraction=0·00045); for weekend walking, the change from baseline to 13 months was 5 min (-8 to 18) in the intervention group and 8 min (-5 to 21) in the control group (difference -1 min [-19 to 17]; pinteraction=0·00045). Neither measure met our predetermined primary outcome of 30 min difference in total walking time between the intervention and control group, so the primary outcome of the trial was not met. One adverse event was reported in a participant who accidently stepped on their Achilles tendon.Interpretation: In a sedentary work environment, treadmill workstations result in a statistically significant but smaller-than-expected increase in daily walking time. Future studies need to investigate how increasing physical activity at work might have potentially compensatory effects on non-work activity.
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| 6. |
- Boraxbekk, Carl-Johan, 1980-, et al.
(författare)
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Diet-Induced Weight Loss Alters Functional Brain Responses during an Episodic Memory Task
- 2015
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Ingår i: Obesity Facts. - : S. Karger AG. - 1662-4025 .- 1662-4033. ; 8:4, s. 261-272
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Tidskriftsartikel (refereegranskat)abstract
- Objective: It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. Methods: 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Results: Episodic memory performance improved significantly (p = 0.010) after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA). Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Conclusions: Diet induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity. (C) 2015 S. Karger GmbH, Freiburg
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| 7. |
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| 8. |
- Stomby, Andreas, et al.
(författare)
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Higher diurnal salivary cortisol levels are related to smaller prefrontal cortex surface area in elderly men and women
- 2016
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Ingår i: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 175:2, s. 117-126
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Elevated cortisol levels with aging have been associated with atrophy of the hippocampus and prefrontal cortex (PFC), as well as with impaired cognitive functions in men. However, coexisting diseases have confounded many studies examining these relationships. Studies in women are lacking. Our objective was to test whether salivary cortisol levels were related to morphology of the hippocampus and the PFC, and to cognitive performance.Design: A cross-sectional study including 200 elderly (55-80 years old) men and women.Method: We used magnetic resonance imaging, tests of episodic-, semantic-, and working memory, visuospatial ability, and cortisol levels in four saliva samples collected during 1 day.Results: Area under the curve (AUC) for cortisol levels was negatively related to cortical surface area of the left anterior cingulate gyrus (caudal P < 0.001; rostral P = 0.006), right lateral orbitofrontal cortex (P = 0.004), and right rostral middle frontal gyrus (P = 0.003). In women, there was also a negative relationship with cortical surface area in the left rostral middle frontal gyrus (P = 0.006). No relationship was found between cortisol levels and hippocampal volume.Conclusion: This study suggests that the structure of the medial PFC is related to cortisol levels in both elderly women and men.
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