Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Physical review. E, Statistical, nonlinear, and soft matter physics, July 2011, Vol.84(1 Pt 2), pp.016703
    Description: Biomolecular simulations have become a major tool in understanding biomolecules and their complexes. However, one can typically only investigate a few mutants or scenarios due to the severe computational demands of such simulations, leading to a great interest in method development to overcome this restriction. One way to achieve this is to reduce the complexity of the systems by an approximation of the forces acting upon the constituents of the molecule. The harmonic approximation used in elastic network models simplifies the physical complexity to the most reduced dynamics of these molecular systems. The reduced polymer modeled this way is typically comprised of mass points representing coarse-grained versions of, e.g., amino acids. In this work, we show how the computation of free energy contributions of contacts between two residues within the molecule can be reduced to a simple lookup operation in a precomputable matrix. Being able to compute such contributions is of great importance: protein design or molecular evolution changes introduce perturbations to these pair interactions, so we need to understand their impact. Perturbation to the interactions occurs due to randomized and fixated changes (in molecular evolution) or designed modifications of the protein structures (in bioengineering). These perturbations are modifications in the topology and the strength of the interactions modeled by the elastic network models. We apply the new algorithm to (1) the bovine trypsin inhibitor, a well-known enzyme in biomedicine, and show the connection to folding properties and the hydrophobic collapse hypothesis and (2) the serine proteinase inhibitor CI-2 and show the correlation to Φ values to characterize folding importance. Furthermore, we discuss the computational complexity and show empirical results for the average case, sampled over a library of 77 structurally diverse proteins. We found a relative speedup of up to 10 000-fold for large proteins with respect to repeated application of the initial model.
    Keywords: Elasticity ; Models, Molecular ; Proteins -- Chemistry
    ISSN: 15393755
    E-ISSN: 1550-2376
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Gait & Posture, October 2015, Vol.42(4), pp.415-418
    Description: Augmented feedback is frequently used in gait training to efficiently correct specific gait patterns in patients with different disorders. The patients use this external augmented feedback to align actual movements in a way that predefined gait characteristics can be achieved. Voluntary changes of gait characteristics are reported to reduce local dynamic stability (LDS) which in turn is associated with increased risk of falling. The aim of this study was to evaluate the instantaneous effect of visual feedback, provided to help patients to correct frontal plane pelvis and trunk movements, on the LDS of pelvis and trunk. Kinematic gait data was captured in ten women with gait disorders. The effect of visual feedback on LDS, quantified with the largest Lyapunov exponent, of walking was examined. We found a significant decreased LDS (e.g. pelvis: = .009) in our subjects when they were using visual augmented feedback. Our data suggest that the use of visual augmented feedback causes less stable gait patterns indicating a reduced ability to respond to small perturbations which might increase risk of falling. Therefore, researchers or clinicians who aim to correct gait patterns through real time based external augmented feedback should consider the potential negative effect on gait stability. It should be evaluated if the possible increased fall risk provoked by visual feedback exceeds possible increases in fall risk induced by conventional gait-retraining interventions. The external validity of the study is limited because of the low sample size and inhomogeneous group characteristics. Thus, further studies including homogeneous cohorts are required.
    Keywords: Gait ; Gait Training ; Local Dynamic Stability ; Fall Risk ; Medicine ; Anatomy & Physiology
    ISSN: 0966-6362
    E-ISSN: 1879-2219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Neuroscience and Biobehavioral Reviews, October 2015, Vol.57, pp.310-327
    Description: This systematic review provides an overview of the literature deducing information about brain activation during (1) imagined walking using MRI/fMRI or (2) during real walking using measurement systems as fNIRS, EEG and PET. Three independent reviewers undertook an electronic database research browsing six databases. The search request consisted of three search fields. The first field comprised common methods to evaluate brain activity. The second search field comprised synonyms for brain responses to movements. The third search field comprised synonyms for walking. 48 of an initial yield of 1832 papers were reviewed. We found differences in cortical activity regarding young vs. old individuals, physically fit vs. physically unfit cohorts, healthy people vs. patients with neurological diseases, and between simple and complex walking tasks. We summarize that the dimension of brain activity in different brain areas during walking is highly sensitive to task complexity, age and pathologies supporting previous assumptions underpinning the significance of cortical control. Many compensation mechanisms reflect the brain's plasticity which ensures stable walking.
    Keywords: Gait ; Mri ; Fmri ; Cortical Activation ; Fnirs ; Cognition ; EEG ; Pet ; Anatomy & Physiology
    ISSN: 0149-7634
    E-ISSN: 1873-7528
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: PMLA, Oct, 2010, Vol.125(4), p.994-1001
    Keywords: Literary Criticism -- Practice ; Philology -- Criticism And Interpretation ; Philology -- Study And Teaching ; Philology -- Practice ; Poetic Techniques -- Criticism And Interpretation
    ISSN: 0030-8129
    E-ISSN: 19381530
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: 2012, Vol.7(12), p.e49804
    Description: Leaking of confidential material is a major threat to information security within organizations and to society as a whole. This insight has gained traction in the political realm since the activities of Wikileaks, which hopes to attack ‘unjust’ systems or ‘conspiracies’. Eventually, such threats to information security rely on a biologistic argument on the benefits and drawbacks that uncontrolled leaking might pose for ‘just’ and ‘unjust’ entities. Such biological metaphors are almost exclusively based on the economic advantage of participants. Here, I introduce a mathematical model of the complex dynamics implied by leaking. The complex interactions of adversaries are modeled by coupled logistic equations including network effects of econo-communication networks. The modeling shows, that there might arise situations where the leaking envisioned and encouraged by Wikileaks and the like can strengthen the defending entity (the ‘conspiracy’). In particular, the only severe impact leaking can have on an organization seems to originate in the exploitation of leaks by another entity the organization competes with. Therefore, the model suggests that leaks can be used as a `tactical mean’ in direct adversary relations, but do not necessarily increase public benefit and societal immunization to ‘conspiracies’. Furthermore, within the model the exploitation of the (open) competition between entities seems to be a more promising approach to control malicious organizations : divide-et-impera policies triumph here.
    Keywords: Research Article ; Biology ; Computer Science ; Mathematics ; Physics ; Social And Behavioral Sciences ; Computer Science ; Physics ; Mathematics
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Archives of Physical Medicine and Rehabilitation, October 2013, Vol.94(10), pp.e65-e65
    Keywords: Medicine ; Physical Therapy
    ISSN: 0003-9993
    E-ISSN: 1532-821X
    Source: ScienceDirect Journals (Elsevier)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Archives of Physical Medicine and Rehabilitation, October 2014, Vol.95(10), pp.e90-e91
    Keywords: Medicine ; Physical Therapy
    ISSN: 0003-9993
    E-ISSN: 1532-821X
    Source: ScienceDirect Journals (Elsevier)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Gait & Posture, September 2014, Vol.40(4), pp.727-729
    Description: Tripping is presumed to be the principal cause for falls during walking. At minimum toe clearance, the potential for trip-related falls is considered to be highest. Thus, controlling minimum toe clearance is essential for walking without tripping. In theory, the central nervous system should therefore give priority to accurate control of the variability in minimum toe clearance, as compared to other gait parameters, since people tend to only modify variability in any given task if it interferes with the task performance. The aim of this study was to determine whether elderly individuals show less increase in variability of minimum toe clearance during a dual-task condition (where an increase of gait variability is provoked), while allowing a larger range of variability in the other gait parameters. Forty elderly participants walked back and forth on a 25 m long track for five minutes. They then walked a second time performing an additional cognitive task. The variability in stride time, stride length and minimum toe clearance as well as dual-task costs of each gait parameter were calculated for each walk. The variability in minimum toe clearance did not change during dual task-walking, whereas the variability of stride length and stride time increased, showing dual-task costs of about 66% and 84%, respectively. To avoid additional detrimental load on the central nervous system, the modification of task-irrelevant variability may be tolerated during dual-task conditions, whereas minimum toe clearance is controlled with high priority.
    Keywords: Minimum Toe Clearance ; Dual-Task Costs ; Gait Variability ; Medicine ; Anatomy & Physiology
    ISSN: 0966-6362
    E-ISSN: 1879-2219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Energy Policy, April, 2012, Vol.43, p.123-135
    Keywords: Renewable Energy -- Research ; Renewable Energy -- Supply And Demand ; Power Grids -- Remodeling And Renovation ; Electric Power Transmission -- Economic Aspects
    ISSN: 0301-4215
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Gait & Posture, June 2012, Vol.36(2), pp.182-186
    Description: ► A visual feedback system to correct pelvis and trunk movements has been evaluated. ► Gait pattern differed in healthy woman and woman with gait disorders. ► Gait pattern improved in woman with gait disorders while using this system. ► The feedback system may be beneficial in gait retraining e.g. in THR patients. Abnormal gait pattern of the frontal plane (i.e. Duchenne gait and Trendelenburg gait) may be caused by a variety of diseases. The aim of this pilot study was to evaluate the instantaneous effect of a visual feedback system on frontal plane pelvis and trunk movements in order to use it in patients with THR in subsequent studies. A total of 24 women (45–65 years) were included in the study. According to acute functional impairments the subjects were assigned to the control group (CG, no gait disorders, = 15, age = 59 ± 11 years, BMI = 27 ± 4) or to the intervention group (IG, = 9, age = 61 ± 4, BMI = 29 ± 5), respectively. First, in Measurement 1 (M1) kinematic reference values were captured in a standardized clinical gait analysis (MVN, XSens). Afterwards, the influence of a visual real-time feedback on gait pattern was examined while using the feedback system (M2). While there was a significant difference of IG vs. CG in M1 in the mean inclination regarding pelvis and trunk movements, this was not detected in M2. Therefore it is concluded, especially in subjects with abnormal gait pattern, that the visualization leads to an improvement of the movement pattern of pelvis and trunk in the frontal plane while using the device.
    Keywords: Visual Feedback ; Trendelenburg Gait ; Duchenne Gait ; Gait Training ; Total Hip Replacement ; Medicine ; Anatomy & Physiology
    ISSN: 0966-6362
    E-ISSN: 1879-2219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages