scholarly journals Group characterization of impact-induced, in vivo human brain kinematics

2021 ◽  
Vol 18 (179) ◽  
pp. 20210251
Author(s):  
Arnold D. Gomez ◽  
Philip V. Bayly ◽  
John A. Butman ◽  
Dzung L. Pham ◽  
Jerry L. Prince ◽  
...  
Keyword(s):  
Brain Size ◽  
Strain Tensor ◽  
Fluid Motion ◽  
Brain Response ◽  
Maximum Shear Strain ◽  
Neck Extension ◽  
Spatio Temporal ◽  
The Individual ◽  
The Impact

Brain movement during an impact can elicit a traumatic brain injury, but tissue kinematics vary from person to person and knowledge regarding this variability is limited. This study examines spatio-temporal brain–skull displacement and brain tissue deformation across groups of subjects during a mild impact in vivo . The heads of two groups of participants were imaged while subjected to a mild (less than 350 rad s −2 ) impact during neck extension (NE, n = 10) and neck rotation (NR, n = 9). A kinematic atlas of displacement and strain fields averaged across all participants was constructed and compared against individual participant data. The atlas-derived mean displacement magnitude was 0.26 ± 0.13 mm for NE and 0.40 ± 0.26 mm for NR, which is comparable to the displacement magnitudes from individual participants. The strain tensor from the atlas displacement field exhibited maximum shear strain (MSS) of 0.011 ± 0.006 for NE and 0.017 ± 0.009 for NR and was lower than the individual MSS averaged across participants. The atlas illustrates common patterns, containing some blurring but visible relationships between anatomy and kinematics. Conversely, the direction of the impact, brain size, and fluid motion appear to underlie kinematic variability. These findings demonstrate the biomechanical roles of key anatomical features and illustrate common features of brain response for model evaluation.

Synthetic Riboswitches for the Analysis of tRNA Processing by eukaryotic RNase P Enzymes

RNA ◽  
2022 ◽  
pp. rna.078814.121
Author(s):  
Anna Ender ◽  
Nadine Grafl ◽  
Tim Kolberg ◽  
Sven Findeiss ◽  
Peter F. Stadler ◽  
...  
Keyword(s):  
Homo Sapiens ◽  
Rnase P ◽  
Single Stranded Region ◽  
Domains Of Life ◽  
The Individual ◽  
The Impact ◽  
Individual Enzyme ◽  
Trna Precursor

Removal of the 5' leader region is an essential step in the maturation of tRNA molecules in all domains of life. This reaction is catalyzed by various RNase P activities, ranging from ribonucleoproteins with ribozyme activity to protein-only forms. In Escherichia coli, the efficiency of RNase P mediated cleavage can be controlled by computationally designed riboswitch elements in a ligand-dependent way, where the 5' leader sequence of a tRNA precursor is either sequestered in a hairpin structure or presented as a single-stranded region accessible for maturation. In the presented work, the regulatory potential of such artificial constructs is tested on different forms of eukaryotic RNase P enzymes – two protein-only RNase P enzymes (PRORP1 and PRORP2) from Arabidopsis thaliana and the ribonucleoprotein of Homo sapiens. The PRORP enzymes were analyzed in vitro as well as in vivo in a bacterial RNase P complementation system. We also tested in HEK293T cells whether the riboswitches remain functional with human nuclear RNase P. While the regulatory principle of the synthetic riboswitches applies for all tested RNase P enzymes, the results also show differences in the substrate requirements of the individual enzyme versions. Hence, such designed RNase P riboswitches represent a novel tool to investigate the impact of the structural composition of the 5'-leader on substrate recognition by different types of RNase P enzymes.

Effects of CSF Properties on Brain Response Under Impact Loading

2009 ◽  
Author(s):  
M. S. Chafi ◽  
V. Dirisala ◽  
G. Karami ◽  
M. Ziejewski
Keyword(s):  
Human Head ◽  
Brain Response ◽  
Pia Mater ◽  
Mechanical Shocks ◽  
The Central Nervous System ◽  
Simultaneous Loading ◽  
The Impact ◽  
Impact Experiments ◽  
The Brain

In the central nervous system, the subarachnoid space is the interval between the arachnoid membrane and the pia mater. It is filled with a clear, watery liquid called cerebrospinal fluid (CSF). The CSF buffers the brain against mechanical shocks and creates buoyancy to protect it from the forces of gravity. The relative motion of the brain due to a simultaneous loading is caused because the skull and brain have different densities and the CSF surrounds the brain. The impact experiments are usually carried out on cadavers with no CSF included because of the autolysis. Even in the cadaveric head impact experiments by Hardy et al. [1], where the specimens are repressurized using artificial CSF, this is not known how far this can replicate the real functionality of CSF. With such motivation, a special interest lies on how to model this feature in a finite element (FE) modeling of the human head because it is questionable if one uses in vivo CSF properties (i.e. bulk modulus of 2.19 GPa) to validate a FE human head against cadaveric experimental data.

scholarly journals The Impact of the Antigenic Composition of Chimeric Proteins on Their Immunoprotective Activity against Chronic Toxoplasmosis in Mice

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 154 ◽  
Author(s):  
Justyna Gatkowska ◽  
Katarzyna Dzitko ◽  
Bartłomiej Tomasz Ferra ◽  
Lucyna Holec-Gąsior ◽  
Malwina Kawka ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Chimeric Proteins ◽  
Protective Capacity ◽  
Antigenic Composition ◽  
Specific Igg ◽  
The Individual ◽  
Immunogenic Properties ◽  
The Impact

Toxoplasmosis may pose a serious threat for individuals with weakened or undeveloped immune systems. However, to date, there is no specific immunoprophylaxis for humans. Thus, the aim of this study was to evaluate the immunogenicity of three trivalent—SAG2-GRA1-ROP1L (SGR), SAG1L-MIC1-MAG1 (SMM), and GRA1-GRA2-GRA6 (GGG)—and two tetravalent—SAG2-GRA1-ROP1-GRA2 (SGRG) and SAG1-MIC1-MAG1-GRA2 (SMMG)—chimeric T. gondii proteins, as well as their protective potential against chronic toxoplasmosis in laboratory mice. All three trivalent recombinant proteins possessed immunogenic properties, as defined by specific humoral and cellular responses in vaccinated mice characterized by the synthesis of specific IgG (IgG1/IgG2a) antibodies in vivo and the release of Th1/Th2 cytokines by stimulated splenocytes in vitro. Immunization with all three recombinant proteins provided partial protection against toxoplasmosis, although the protective capacity strongly depended on the individual antigenic composition of each preparation. The antigens providing the highest (86%) and lowest (45%) protection, SGR and SMM, respectively, were supplemented with GRA2 antigen fragment, to form the tetravalent chimeric proteins SGRG and SMMG. Further study revealed that the tetravalent preparations exhibited high immunogenic potential; however, the addition of another antigen to the recombinant protein structure had distinct effects on the protection generated, compared to that of the trivalent counterparts, depending on the antigen tested.

scholarly journals White-matter degradation and dynamical compensation support age-related functional alterations in human brain

2022 ◽  
Author(s):  
Spase Petkoski ◽  
Petra Ritter ◽  
Viktor Jirsa
Keyword(s):  
Average Length ◽  
Temporal Structure ◽  
Structural Connectivity ◽  
Bimodal Distribution ◽  
Brain Network ◽  
Age Related ◽  
Spatio Temporal ◽  
The Individual ◽  
The Impact ◽  
The Brain

Structural connectivity of the brain at different ages is analyzed using diffusion-weighted Magnetic Resonance Imaging (MRI) data. The largest decrease of the number and average length of stream- lines is found for the long inter-hemispheric links, with the strongest impact for frontal regions. From the BOLD functional MRI (fMRI) time series we identify age-related changes of dynamic functional connectivity (dFC) and spatial covariation features of the FC links captured by meta- connectivity (MC). They indicate more constant dFC, but wider range and variance of MC. Finally we applied computational whole-brain network model based on oscillators, which mechanistically expresses the impact of the spatio-temporal structure of the brain (weights and the delays) to the dynamics. With this we tested several hypothesis, which revealed that the spatio-temporal reorga- nization of the brain with ageing, supports the observed functional fingerprints only if the model accounts for: (i) compensation of the individual brains for the overall loss of structural connectivity, and (ii) decrease of propagation velocity due to the loss of myelination. We also show that having these two conditions, it is sufficient to decompose the time-delays as bimodal distribution that only distinguishes between intra- and inter-hemispheric delays, and that the same working point also captures the static FC the best.

scholarly journals Prioritization of the vector factors controlling <i>Emiliania huxleyi</i> blooms in subarctic and arctic seas: A multidimensional statistical approach

2019 ◽  
Author(s):  
Dmitry Kondrik ◽  
Eduard Kazakov ◽  
Svetlana Chepikova ◽  
Dmitry Pozdnyakov
Keyword(s):  
Statistical Approach ◽  
Temporal Dynamics ◽  
Remote Sensing Data ◽  
Marine Ecology ◽  
Arctic Seas ◽  
Prediction Ability ◽  
The North ◽  
Spatio Temporal ◽  
The Individual ◽  
The Impact

Abstract. Producing very extensive blooms in the world's oceans in both hemispheres, a coccolithophore E. huxleyi is capable of affecting both the marine ecology and carbon fluxes at the atmosphere-ocean interface. At the same time, it is subject to the impact of multiple co-acting environmental forcings, which determine the spatio-temporal dynamics of E. huxleyi blooming phenomenon. To reveal the individual importance of each forcing factor (FF) that is known to significantly control the extent and intensity of E. huxleyi blooms and can be retrieved from remote sensing data, we used long-term spatial time series (1998–2016) of sea surface temperature and salinity, incident photosynthetically active radiation, and Ekman layer depth relevant to the marine environments located in the North Atlantic, Arctic and North Pacific oceans, namely the North, Norwegian, Greenland, Labrador, Barents and Bering seas. The FFs retrieved were subjected to statistical analyses. The descriptive statistical approach has shown that E. huxleyi phytoplankton were highly adaptive to the environmental conditions and capable of arising and developing within wide FFs ranges, which proved to be expressly sea-specific. It was also found that there were FFs optimal ranges (also sea-specific), within which the blooms were particularly extensive. The application of the Random Forest Classifier (RFC) approach to each target sea allowed to reliably rank the FFs considered in terms of their role in the spatio-temporal dynamics of E. huxleyi blooms. With the only exception of the Bering Sea, allegedly due to temporally established untypical hydrological conditions, the prediction ability of RFC modeling characterized in terms of precision, recall, and f1-score generally was in excess of 70 %, thus indicating the adequacy of the developed models for FFs prioritization with regard to E. huxleyi blooms.

scholarly journals Delineating the macroscale areal organization of the macaque cortex in vivo

2017 ◽  
Author(s):  
Ting Xu ◽  
Arnaud Falchier ◽  
Elinor L. Sullivan ◽  
Gary Linn ◽  
Julian Ramirez ◽  
...  
Keyword(s):  
Individual Differences ◽  
Motor Cortex ◽  
Translational Research ◽  
Higher Order ◽  
The Individual ◽  
The Impact ◽  
Data Requirements ◽  
Human Primate

SUMMARYComplementing longstanding traditions centered around histology, fMRI approaches are rapidly maturing in delineating brain areal organization at the macroscale. The non-human primate (NHP) provides the opportunity to overcome critical barriers in translational research. Here, we establish the data and scanning conditions for achieving reproducible, stable and internally valid areal parcellations in individuals. We demonstrate that these functional boundaries serve as a functional fingerprint of the individual animals, and can be achieved under anesthesia or awake conditions (rest, naturalistic viewing), though differences between awake and anesthetized states precluded the detection of individual differences across states. Comparison of awake and anesthetized states suggested a more nuanced picture of changes in connectivity for higher order association areas, as well as visual and motor cortex. These results establish feasibility and data requirements for the generation of reproducible individual-specific parcellations in NHP, as well as provide insights into the impact of scan state and motivate efforts toward harmonizing protocols.

scholarly journals Single Lysophosphatidylcholine Components Exhibit Adjuvant Activities In Vitro and In Vivo

2010 ◽  
Vol 17 (3) ◽  
pp. 429-438 ◽  
Author(s):  
Guillaume Bach ◽  
Laure Perrin-Cocon ◽  
Estelle Gerossier ◽  
Aurélie Guironnet-Paquet ◽  
Vincent Lotteau ◽  
...  
Keyword(s):  
Gamma Interferon ◽  
Active Components ◽  
Phenotypic Analysis ◽  
Virus Surface ◽  
Monocyte Chemoattractant Protein 1 ◽  
Inducible Protein ◽  
The Individual ◽  
The Impact

ABSTRACT Improving vaccine immunogenicity by developing new adjuvant formulations has long been a goal of vaccinologists. It has previously been shown that a natural mix of lysophosphatidylcholine (LPC) from chicken eggs promotes mature dendritic cell (DC) generation in vitro and primes antigen-specific immune responses in mice. In the present study, we dissected the adjuvant potentials of five individual LPC components found in the chicken egg mixture. In vitro analyses of the impact of the individual components on the maturation of human DCs were performed by means of phenotypic analysis, chemokine secretion analysis, and analysis of the ability of mature DC to stimulate T lymphocytes. Two components, C16:0-LPC and C18:0-LPC, were identified to be capable of the upregulation of expression of CD86, HLA-DR, and CD40 on in vitro-cultured monocyte-derived DCs from healthy donors. Both induced the release of chemokines to high concentrations (macrophage inflammatory protein 1, monocyte chemoattractant protein 1) or moderate concentrations (interleukin-8 [IL-8], gamma interferon-inducible protein 10). In addition, C16:0-LPC engaged naïve T cells to produce gamma interferon. This suggests that C16:0-LPC and C18:0-LPC have the capacity to promote, at least in vitro, a Th1-oriented response. The intravenous injection of C16:0-LPC or C18:0-LPC into mice resulted in the detectable secretion of IL-6 and IL-5 in sera. Both LPC components were tested for their capacities to act as adjuvants for two selected immunogens: the hepatitis B virus surface antigen and the hepatitis C virus NS3 helicase. The secretion of specific IgG1 was observed with either or both C16:0-LPC and C18:0-LPC, depending on the immunogen tested, and was observed at an efficiency comparable to that of alum. These data identify C16:0-LPC and C18:0-LPC as the active components of the LPC natural mixture. Although discrepancies between the results of the in vitro and in vivo analyses existed, studies with animals suggest that these components can trigger significant and specific humoral-mediated immunity.

scholarly journals Scaffold modelling captures the structure-function-dynamics relationship in brain microcircuits

2021 ◽  
Author(s):  
Robin Gilbert De Schepper ◽  
Alice Geminiani ◽  
Stefano Masoli ◽  
Martina Francesca Rizza ◽  
Alberto Antonietti ◽  
...  
Keyword(s):  
Ground Truth ◽  
Signal Propagation ◽  
Neuron Models ◽  
Modeling Framework ◽  
Multiple Strategies ◽  
Spatio Temporal ◽  
Cell Placement ◽  
Flexible Management ◽  
The Impact

Modelling brain networks with complex configuration and cellular properties requires a set of neuroinformatic tools and an organized staged workflow. We have therefore developed the Brain Scaffold Builder (BSB), a new modeling framework embedding multiple strategies for cell placement and connectivity and a flexible management of cellular and network mechanisms. With BSB, for the first time, the mouse cerebellar cortex was reconstructed and simulated at cellular resolution, using morphologically realistic multi-compartmental single-neuron models. Embedded connection rules allowed BSB to generate the cerebellar connectome, unifying a collection of scattered experimental data into a coherent construct. Naturalistic background and sensory-burst stimulation were used for functional validation against recordings in vivo, monitoring the impact of subcellular mechanisms on signal propagation and spatio-temporal processing and providing a new ground-truth about circuit organization for the prediction of neural dynamics.

Accent Policy and Accent Modification Enterprises as Potential Indicators of Intercultural Power Relations: A Call for an Updated Research Agenda

2013 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty
Keyword(s):  
International Relations ◽  
Identity Construction ◽  
Social Theory ◽  
Power Relations ◽  
Linguistic Diversity ◽  
Cultural Organization ◽  
Using Data ◽  
The Individual ◽  
The Impact ◽  
The Relationship

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.

Investigating the Relationship Between Self-Esteem and Stigma Among Young Adults With History of Suicide Attempts

Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder
Keyword(s):  
Young Adults ◽  
Suicide Attempts ◽  
Self Esteem ◽  
High Risk Population ◽  
High Functioning ◽  
People With Mental Illness ◽  
History Of ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.

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