234 research outputs found
Focused-attention meditation increases cognitive control during motor sequence performance: Evidence from the N2 cortical evoked potential
Previous work found that single-session focused attention meditation (FAM) enhanced motor sequence learning through increased cognitive control as a mechanistic action, although electrophysiological correlates of sequence learning performance following FAM were not investigated. We measured the persistent frontal N2 event-related potential (ERP) that is closely related to cognitive control processes and its ability to predict behavioural measures. Twenty-nine participants were randomised to one of three conditions reflecting the level of FAM experienced prior to a serial reaction time task (SRTT): 21 sessions of FAM (FAM21, N = 12), a single FAM session (FAM1, N = 9) or no preceding FAM control (Control, N = 8). Continuous 64-channel EEG were recorded during SRTT and N2 amplitudes for correct trials were extracted. Component amplitude, regions of interests, and behavioural outcomes were compared using mixed effects regression models between groups. FAM21 exhibited faster reaction time performances in majority of the learning blocks compared to FAM1 and Control. FAM21 also demonstrated a significantly more pronounced N2 over majority of anterior and central regions of interests during SRTT compared to the other groups. When N2 amplitudes were modelled against general learning performance, FAM21 showed the greatest rate of amplitude decline over anterior and central regions. The combined results suggest that FAM training provided greater cognitive control enhancement for improved general performance, and less pronounced effects for sequence-specific learning performance compared to the other groups. Importantly, FAM training facilitates dynamic modulation of cognitive control: lower levels of general learning performance was supported by greater levels of activation, whilst higher levels of general learning exhibited less activation
Two 'transitions': the political economy of Joyce Banda's rise to power and the related role of civil society organisations in Malawi
This is an Accepted Manuscript of an article published by Taylor & Francis in Review of African Political Economy on 21/07/2014, available online: http://www.tandfonline.com/doi/abs/10.1080/03056244.2014.90194
Sequence Motifs in MADS Transcription Factors Responsible for Specificity and Diversification of Protein-Protein Interaction
Protein sequences encompass tertiary structures and contain information about specific molecular interactions, which in turn determine biological functions of proteins. Knowledge about how protein sequences define interaction specificity is largely missing, in particular for paralogous protein families with high sequence similarity, such as the plant MADS domain transcription factor family. In comparison to the situation in mammalian species, this important family of transcription regulators has expanded enormously in plant species and contains over 100 members in the model plant species Arabidopsis thaliana. Here, we provide insight into the mechanisms that determine protein-protein interaction specificity for the Arabidopsis MADS domain transcription factor family, using an integrated computational and experimental approach. Plant MADS proteins have highly similar amino acid sequences, but their dimerization patterns vary substantially. Our computational analysis uncovered small sequence regions that explain observed differences in dimerization patterns with reasonable accuracy. Furthermore, we show the usefulness of the method for prediction of MADS domain transcription factor interaction networks in other plant species. Introduction of mutations in the predicted interaction motifs demonstrated that single amino acid mutations can have a large effect and lead to loss or gain of specific interactions. In addition, various performed bioinformatics analyses shed light on the way evolution has shaped MADS domain transcription factor interaction specificity. Identified protein-protein interaction motifs appeared to be strongly conserved among orthologs, indicating their evolutionary importance. We also provide evidence that mutations in these motifs can be a source for sub- or neo-functionalization. The analyses presented here take us a step forward in understanding protein-protein interactions and the interplay between protein sequences and network evolution
Waardevolle perspectieven voor vlees
Dit rapport doet verslag van een onderzoek waarin is gekeken hoe vlees in de keten op een andere manier tot waarde kan worden gebracht zodat dit lonend is voor de partijen in de keten. Hierbij geldt: de beloning komt zo veel mogelijk toe aan degene die de toegevoegde waarde levert. Dit initiatief richt zich daarbij op het ontwikkelen en beoordelen van alternatieve businessmodellen met een ander 'waarde(n)perspectief' voor pluimvee- en varkensvlees(producten)
Continuous-time modeling of cell fate determination in Arabidopsis flowers
<p>Abstract</p> <p>Background</p> <p>The genetic control of floral organ specification is currently being investigated by various approaches, both experimentally and through modeling. Models and simulations have mostly involved boolean or related methods, and so far a quantitative, continuous-time approach has not been explored.</p> <p>Results</p> <p>We propose an ordinary differential equation (ODE) model that describes the gene expression dynamics of a gene regulatory network that controls floral organ formation in the model plant <it>Arabidopsis thaliana</it>. In this model, the dimerization of MADS-box transcription factors is incorporated explicitly. The unknown parameters are estimated from (known) experimental expression data. The model is validated by simulation studies of known mutant plants.</p> <p>Conclusions</p> <p>The proposed model gives realistic predictions with respect to independent mutation data. A simulation study is carried out to predict the effects of a new type of mutation that has so far not been made in <it>Arabidopsis</it>, but that could be used as a severe test of the validity of the model. According to our predictions, the role of dimers is surprisingly important. Moreover, the functional loss of any dimer leads to one or more phenotypic alterations.</p
Risk communication in a patient decision aid for radiotherapy in breast cancer:How to deal with uncertainty?
Background and aim: Patient decision aids for oncological treatment options, provide information on the
effect on recurrence rates and/or survival benefit, and on side-effects and/or burden of different treatment options. However, often uncertainty exists around the probability estimates for recurrence/survival
and side-effects which is too relevant to be ignored. Evidence is lacking on the best way to communicate
these uncertainties. The aim of this study is to develop a method to incorporate uncertainties in a patient
decision aid for breast cancer patients to support their decision on radiotherapy.
Methods: Firstly, qualitative interviews were held with patients and health care professionals. Secondly,
in the development phase, thinking aloud sessions were organized with four patients and 12 health care
professionals, individual and group-wise.
Results: Consensus was reached on a pictograph illustrating the whole range of uncertainty for local
recurrence risks, in combination with textual explanation that a more exact personalized risk would be
given by their own physician. The pictograph consisted of 100 female icons in a 10 x 10 array. Icons with a
stepwise gradient color indicated the uncertainty margin. The prevalence and severity of possible sideeffects were explained using verbal labels.
Conclusions: We developed a novel way of visualizing uncertainties in recurrence rates in a patient
decision aid. The effect of this way of communicating risk uncertainty is currently being tested in the
BRASA study (NCT03375801)
Dierenwelzijn in transitie; Thema's rond de implementatie van de dierenwelzijnsindex
LNV wil het proces van dierenwelzijnsverbetering in de veehouderij tot een bovenwettelijk niveau stimuleren en ondersteunen met onderzoek waarin de dierenwelzijnsindex centraal staat. Dit rapport bespreekt verschillende thema's rond de implementatie van die dierenwelzijnsindex. De implementatie van de index wordt gezien binnen de structurele ontwikkeling naar een meer duurzame veehouderij. Specifiek is er in het rapport aandacht voor gedragscodeorganisaties, dierenbeschermingsgroepen, meerkosten van dierenwelzijnsmaatregelen en financiële beleidsinstrumenten. Tevens wordt er een 'doorkijk' geformuleerd naar de implementatie van de index
Generic nano-imprint process for fabrication of nanowire arrays
A generic process has been developed to grow nearly defect free arrays of
(heterostructured) InP and GaP nanowires. Soft nanoimprint lithography has been
used to pattern gold particle arrays on full 2 inch substrates. After lift-off
organic residues remain on the surface, which induce the growth of additional
undesired nanowires. We show that cleaning of the samples before growth with
piranha solution in combination with a thermal anneal at 550 C for InP and 700
C for GaP results in uniform nanowire arrays with 1% variation in nanowire
length, and without undesired extra nanowires. Our chemical cleaning procedure
is applicable to other lithographic techniques such as e-beam lithography, and
therefore represents a generic process.Comment: 12 pages, 4 figures, 2 table
Dynamic cerebral autoregulation after intracerebral hemorrhage: A case-control study
<p>Abstract</p> <p>Background</p> <p>Dynamic cerebral autoregulation after intracerebral hemorrhage (ICH) remains poorly understood. We performed a case-control study to compare dynamic autoregulation between ICH patients and healthy controls.</p> <p>Methods</p> <p>Twenty-one patients (66 ± 15 years) with early (< 72 hours) lobar or basal ganglia ICH were prospectively studied and compared to twenty-three age-matched controls (65 ± 9 years). Continuous measures of mean flow velocity (MFV) in the middle cerebral artery and mean arterial blood pressure (MAP) were obtained over 5 min. Cerebrovascular resistance index (CVR<sub>i</sub>) was calculated as the ratio of MAP to MFV. Dynamic cerebral autoregulation was assessed using transfer function analysis of spontaneous MAP and MFV oscillations in the low (0.03-0.15 Hz) and high (0.15-0.5 Hz) frequency ranges.</p> <p>Results</p> <p>The ICH group demonstrated higher CVR<sub>i </sub>compared to controls (ipsilateral: 1.91 ± 1.01 mmHg·s·cm<sup>-1</sup>, <it>p </it>= 0.04; contralateral: 2.01 ± 1.24 mmHg·s·cm<sup>-1</sup>, <it>p </it>= 0.04; vs. control: 1.42 ± 0.45 mmHg·s·cm<sup>-1</sup>). The ICH group had higher gains than controls in the low (ipsilateral: 1.33 ± 0.58%/mmHg, <it>p </it>= 0.0005; contralateral: 1.47 ± 0.98%/mmHg, <it>p </it>= 0.004; vs. control: 0.82 ± 0.30%/mmHg) and high (ipsilateral: 2.11 ± 1.31%/mmHg, <it>p </it>< 0.0001; contralateral: 2.14 ± 1.49%/mmHg, <it>p </it>< 0.0001; vs. control: 0.66 ± 0.26%/mmHg) frequency ranges. The ICH group also had higher coherence in the contralateral hemisphere than the control (ICH contralateral: 0.53 ± 0.38, <it>p </it>= 0.02; vs. control: 0.38 ± 0.15) in the high frequency range.</p> <p>Conclusions</p> <p>Patients with ICH had higher gains in a wide range of frequency ranges compared to controls. These findings suggest that dynamic cerebral autoregulation may be less effective in the early days after ICH. Further study is needed to determine the relationship between hematoma size and severity of autoregulation impairment.</p
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