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| 2. |
- Andrew, Churchill, et al.
(författare)
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Vision of the hand and environmental context in human prehension
- 2000
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 134:1, s. 81-89
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Tidskriftsartikel (refereegranskat)abstract
- Previous findings on the role of visual contact with the hand in the control of reaching and grasping have been contradictory. Some studies have shown that such contact is largely irrelevant, while more recent ones have emphasised its importance. In contrast, information arising from the surrounding environment has received relatively little attention in the study of prehensile actions. In order to identify the roles of both sources of information, we made kinematic comparisons between three conditions. In the first, reaching was performed in a dimly lit room and compared with a second condition in which reaches in the dark, but with the thumb and first finger illuminated, were made to a luminous object. This contrast allows the effects of environmental context to be identified. A comparison between the second and a third condition, in which both vision of the hand and the environment was removed, but the object was still visually available, enabled the assessment of how and when vision of the hand plays a role. Removing environmental cues had effects both early and late in the reach, while vision of the hand was only crucial in the period after peak deceleration. In addition, removal of both sources of information resulted in larger grip apertures. Differences and similarities between our findings and those of other studies are discussed, as is the ongoing debate about the relative importance of visual feedback of the hand in the control and co-ordination of prehensile actions. We conclude with suggestions for further research based on the set-up used in the present study.
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| 3. |
- Domellöf, Erik, 1970-, et al.
(författare)
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Functional asymmetries in the stepping response of the human newborn : a kinematic approach
- 2007
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Ingår i: Experimental Brain Research. - : Springer Berlin/Heidelberg. - 0014-4819 .- 1432-1106. ; 177:3, s. 324-335
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate subtle expressions of functional asymmetries in newborn leg movements, kinematic registrations were made on a sample of 40 healthy fullterm newborn infants during performance of the stepping response. Time–position data were collected from markers attached to the hip, knee and ankle joints of the left and right leg, and movements of both legs recorded simultaneously. Findings included evident side differences in terms of smoother trajectories of the right leg as a consequence of less movement segmentation compared to the left leg. Additionally, analyses of intralimb coordination revealed side differences with regard to stronger ankle–knee couplings and smaller phase shifts in the right leg. The findings suggest that asymmetries in newborn stepping responses are present in terms of spatio-temporal parameters and intralimb coordination. No evidence of a lateral preference in terms of frequency of the first foot moved was found. The present study adds new understanding to the lateralized attributes of the stepping response in the human newborn and as such points to new directions of research on the nature of laterality in the future.
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| 4. |
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| 5. |
- Domellöf, Erik, 1970-, et al.
(författare)
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Upper and lower body functional asymmetries in the newborn : do they have the same lateral biases?
- 2005
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Ingår i: Developmental Psychobiology. - New York : Wiley. - 0012-1630 .- 1098-2302. ; 46:2, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- It is still an open question as to whether functional asymmetries in the human newborn derive from a single lateralized system or multiple subsystems based on different neural mechanisms. In the present study, asymmetries in head turning were compared to those in leg movements during stepping and placing, with the latter also being related to differences in leg mass. The effects of an active versus an inactive state or condition were examined for all three behaviors. No overall lateral biases were found for head turning or for the first foot to move in stepping and placing, and there were no concordances among them; however, there was an asymmetry in that the left foot had a shorter onset latency when compared to the right foot for both stepping and placing. Findings are discussed in terms of what they imply about underlying neural systems that have a bearing on expressions of newborn laterality, and also with regard to the impact of methodological differences in this area of study.
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| 6. |
- Hopkins, Brian, et al.
(författare)
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Facilitating postural control : effects on the reaching behavior of 6‐month‐old infants
- 2002
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Ingår i: Developmental Psychobiology. - : Wiley-Blackwell. - 0012-1630 .- 1098-2302. ; 40:2, s. 168-182
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Tidskriftsartikel (refereegranskat)abstract
- In this study, 3-D kinematic as well as 2-D videorecordings were made of the reaching behavior of infants aged about 6 months who were not yet able to sit. Detailed analyses of these recordings were directed toward specifying the effects of providing additional postural support to the lower body on the spatial and temporal features of such behavior. To detect these effects, reaching and associated head movements in this modified condition were compared to those made while the infants sat in an age-appropriate and commercially available chair lacking the supplementation of support for the pelvic region and upper legs. Findings consistent with predictions included better head stabilization and smoother reaching movements when the infants were in the modified chair. In addition, these two achievements were negatively related to reaching experience. These, and other findings, underscore the infrequently investigated supposition that changes in postural control induce improvements in the control of reaching movements during infancy. Recommendations are made about how the procedure adopted in the present study could be used in subsequent research to give further insights into the codevelopment of posture and action.
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| 7. |
- Hopkins, Brian, et al.
(författare)
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Human handedness : developmental, and evolutionary perspectives
- 1998
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Ingår i: The development of sensory, motor and cognitive capacities in early infancy. - Hove, East Sussex, UK : Psychology Press. - 0863775128 ; , s. 191-236
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Bokkapitel (refereegranskat)abstract
- Argues (1) that handedness in humans has a greater evolutionary depth than speech and language and perhaps even habitual bipedalism, (2) that the developmental origins of handedness are based on different mechanisms than for speech and language, (3) that there is no simple task (e.g., reaching) that will provide a valid index of handedness during the 1st year, (4) that studies on the development of handedness need to be more sensitive to the roles of task and S variables, and (5) that the development of handedness should be addressed by models that incorporate hand preference into different modes of bimanual coordination. Topics discussed include: the ontology of handedness, the evolutionary origins of handedness, the developmental origins of human handedness, and the development of handedness in newborns and beyond.
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| 8. |
- Khatri, C, et al.
(författare)
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Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
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Tidskriftsartikel (refereegranskat)abstract
- Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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| 9. |
- Kim, Ji Hoon, et al.
(författare)
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THE AGORA HIGH-RESOLUTION GALAXY SIMULATIONS COMPARISON PROJECT. II. ISOLATED DISK TEST
- 2016
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 833:2
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Tidskriftsartikel (refereegranskat)abstract
- Using an isolated Milky Way-mass galaxy simulation, we compare results from nine state-of-the-art gravito-hydrodynamics codes widely used in the numerical community. We utilize the infrastructure we have built for the AGORA High-resolution Galaxy Simulations Comparison Project. This includes the common disk initial conditions, common physics models (e.g., radiative cooling and UV background by the standardized package Grackle) and common analysis toolkit yt, all of which are publicly available. Subgrid physics models such as Jeans pressure floor, star formation, supernova feedback energy, and metal production are carefully constrained across code platforms. With numerical accuracy that resolves the disk scale height, we find that the codes overall agree well with one another in many dimensions including: gas and stellar surface densities, rotation curves, velocity dispersions, density and temperature distribution functions, disk vertical heights, stellar clumps, star formation rates, and Kennicutt-Schmidt relations. Quantities such as velocity dispersions are very robust (agreement within a few tens of percent at all radii) while measures like newly formed stellar clump mass functions show more significant variation (difference by up to a factor of ∼3). Systematic differences exist, for example, between mesh-based and particle-based codes in the low-density region, and between more diffusive and less diffusive schemes in the high-density tail of the density distribution. Yet intrinsic code differences are generally small compared to the variations in numerical implementations of the common subgrid physics such as supernova feedback. Our experiment reassures that, if adequately designed in accordance with our proposed common parameters, results of a modern high-resolution galaxy formation simulation are more sensitive to input physics than to intrinsic differences in numerical schemes.
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| 10. |
- Koruza, Katarina, et al.
(författare)
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Biophysical Characterization of Cancer-Related Carbonic Anhydrase IX
- 2020
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 21:15
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Tidskriftsartikel (refereegranskat)abstract
- Upregulation of carbonic anhydrase IX (CA IX) is associated with several aggressive forms of cancer and promotes metastasis. CA IX is normally constitutively expressed at low levels in selective tissues associated with the gastrointestinal tract, but is significantly upregulated upon hypoxia in cancer. CA IX is a multi-domain protein, consisting of a cytoplasmic region, a single-spanning transmembrane helix, an extracellular CA catalytic domain, and a proteoglycan-like (PG) domain. Considering the important role of CA IX in cancer progression and the presence of the unique PG domain, little information about the PG domain is known. Here, we report biophysical characterization studies to further our knowledge of CA IX. We report the 1.5 Å resolution crystal structure of the wild-type catalytic domain of CA IX as well as small angle X-ray scattering and mass spectrometry of the entire extracellular region. We used matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to characterize the spontaneous degradation of the CA IX PG domain and confirm that it is only the CA IX catalytic domain that forms crystals. Small angle X-ray scattering analysis of the intact protein indicates that the PG domain is not randomly distributed and adopts a compact distribution of shapes in solution. The observed dynamics of the extracellular domain of CA IX could have physiological relevance, including observed cleavage and shedding of the PG domain.
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