7,652 research outputs found

    Chromosomes Can Congress to the Metaphase Plate Before Biorientation

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    The stable propagation of genetic material during cell division depends on the congression of chromosomes to the spindle equator before the cell initiates anaphase. It is generally assumed that congression requires that chromosomes are connected to the opposite poles of the bipolar spindle (“bioriented”). In mammalian cells, we found that chromosomes can congress before becoming bioriented. By combining the use of reversible chemical inhibitors, live-cell light microscopy, and correlative electron microscopy, we found that monooriented chromosomes could glide toward the spindle equator alongside kinetochore fibers attached to other already bioriented chromosomes. This congression mechanism depended on the kinetochore-associated, plus end–directed microtubule motor CENP-E (kinesin-7)

    An Efficient Algorithm for Enumerating Chordless Cycles and Chordless Paths

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    A chordless cycle (induced cycle) CC of a graph is a cycle without any chord, meaning that there is no edge outside the cycle connecting two vertices of the cycle. A chordless path is defined similarly. In this paper, we consider the problems of enumerating chordless cycles/paths of a given graph G=(V,E),G=(V,E), and propose algorithms taking O(E)O(|E|) time for each chordless cycle/path. In the existing studies, the problems had not been deeply studied in the theoretical computer science area, and no output polynomial time algorithm has been proposed. Our experiments showed that the computation time of our algorithms is constant per chordless cycle/path for non-dense random graphs and real-world graphs. They also show that the number of chordless cycles is much smaller than the number of cycles. We applied the algorithm to prediction of NMR (Nuclear Magnetic Resonance) spectra, and increased the accuracy of the prediction

    Facilitated early discharge in Wandsworth

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    OBJECTIVE: There is limited research surrounding facilitated early discharge (FD) and Home Treatment Teams (HTTs). This study aimed to compare patients who received FD with patients who were discharged without FD to identify whether there were significant differences in terms of social demographics, illness characteristics, health outcome and treatment duration. Using this data we furthermore aimed to provide proposals to help advance the effectiveness of FD, as well as suggesting concepts of where future research should lie. CASE REPORT: A randomised sample of patients who received FD and patients who were discharged without FD was obtained from a South London Hospital. This was manually narrowed down to patients specifically treated by the Wandsworth Home Treatment Team (WHTT). Socio-demographic and clinical data were then attained from the patients’ electronic records to compare and statistically analyse between the two groups. DISCUSSION: Patients who received FD from the WHTT were found to have significantly less previous psychiatric admissions compared to those who were discharged without FD (p = 0.032). All other variables were found to have no association with FD. CONCLUSION: Having a high number of previous psychiatric admissions seems to be an aspect that decreases the chance of being allocated FD. This variable can be seen as an indicator of severity of illness and a challenging social environment; it could therefore be valuable to take this variable into consideration when allocating FD. Furthermore, total treatment duration was found to not be significantly different for FD and non-FD patients, thus supporting the use of CRHTTs as an equivalent alternative for inpatient admission, however, national scale research should be conducted to strengthen and expand on these findings

    Mycobacterium tuberculosis CarD, an essential global transcriptional regulator forms amyloid-like fibrils

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    CarD is an essential global transcription regulator from Mycobacterium tuberculosis (Mtb) that binds RNA polymerase and activates transcription by stabilizing the transcription initiation complex. Available crystal structures have captured two distinct, monomeric and domain-swapped homodimeric, oligomeric states of CarD. However, the actual oligomeric state of CarD in solution and its biological relevance has remained unclear. Here, we confirm the presence of the homodimeric state of CarD in solution by using synchrotron-based small-angle X-ray scattering. Furthermore, by using biochemical and biophysical experiments, in addition to mass-spectrometry, transmission electron microscopy, and confocal imaging, we show that CarD is the first soluble cytosolic protein in Mtb which displays the tendency to form amyloid-like fibrils both in vitro as well as in vivo. We demonstrate that the deletion of the fourteen N-terminal residues involved in domain-swapping hampers amyloid formation, thus, suggesting that domain-swapping is crucial in amyloidogenesis. The discovery of the amyloidogenic property of an essential cytosolic global transcription regulator, CarD, in a pathogenic bacteria will further open up new frontiers in research.Peer reviewe

    Synthetic Analogues of the Snail Toxin 6-Bromo-2-mercaptotryptamine Dimer (BrMT) Reveal That Lipid Bilayer Perturbation Does Not Underlie Its Modulation of Voltage-Gated Potassium Channels

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    Drugs do not act solely by canonical ligand–receptor binding interactions. Amphiphilic drugs partition into membranes, thereby perturbing bulk lipid bilayer properties and possibly altering the function of membrane proteins. Distinguishing membrane perturbation from more direct protein–ligand interactions is an ongoing challenge in chemical biology. Herein, we present one strategy for doing so, using dimeric 6-bromo-2-mercaptotryptamine (BrMT) and synthetic analogues. BrMT is a chemically unstable marine snail toxin that has unique effects on voltage-gated K+ channel proteins, making it an attractive medicinal chemistry lead. BrMT is amphiphilic and perturbs lipid bilayers, raising the question of whether its action against K+ channels is merely a manifestation of membrane perturbation. To determine whether medicinal chemistry approaches to improve BrMT might be viable, we synthesized BrMT and 11 analogues and determined their activities in parallel assays measuring K+ channel activity and lipid bilayer properties. Structure–activity relationships were determined for modulation of the Kv1.4 channel, bilayer partitioning, and bilayer perturbation. Neither membrane partitioning nor bilayer perturbation correlates with K+ channel modulation. We conclude that BrMT’s membrane interactions are not critical for its inhibition of Kv1.4 activation. Further, we found that alkyl or ether linkages can replace the chemically labile disulfide bond in the BrMT pharmacophore, and we identified additional regions of the scaffold that are amenable to chemical modification. Our work demonstrates a strategy for determining if drugs act by specific interactions or bilayer-dependent mechanisms, and chemically stable modulators of Kv1 channels are reported

    Setting a research agenda for progressive multiple sclerosis: The International Collaborative on Progressive MS

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    Despite significant progress in the development of therapies for relapsing MS, progressive MS remains comparatively disappointing. Our objective, in this paper, is to review the current challenges in developing therapies for progressive MS and identify key priority areas for research. A collaborative was convened by volunteer and staff leaders from several MS societies with the mission to expedite the development of effective disease-modifying and symptom management therapies for progressive forms of multiple sclerosis. Through a series of scientific and strategic planning meetings, the collaborative identified and developed new perspectives on five key priority areas for research: experimental models, identification and validation of targets and repurposing opportunities, proof-of-concept clinical trial strategies, clinical outcome measures, and symptom management and rehabilitation. Our conclusions, tackling the impediments in developing therapies for progressive MS will require an integrated, multi-disciplinary approach to enable effective translation of research into therapies for progressive MS. Engagement of the MS research community through an international effort is needed to address and fund these research priorities with the ultimate goal of expediting the development of disease-modifying and symptom-relief treatments for progressive MS

    Characteristics Associated With Facebook Use and Interest in Digital Disease Support Among Older Adults With Atrial Fibrillation: Cross-Sectional Analysis of Baseline Data From the Systematic Assessment of Geriatric Elements in Atrial Fibrillation (SAGE-AF) Cohort

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    BACKGROUND: Online support groups for atrial fibrillation (AF) and apps to detect and manage AF exist, but the scientific literature does not describe which patients are interested in digital disease support. OBJECTIVE: The objective of this study was to describe characteristics associated with Facebook use and interest in digital disease support among older patients with AF who used the internet. METHODS: We used baseline data from the Systematic Assessment of Geriatric Elements in Atrial Fibrillation (SAGE-AF), a prospective cohort of older adults ( \u3e /=65 years) with AF at high stroke risk. Participants self-reported demographics, clinical characteristics, and Facebook and technology use. Online patients (internet use in the past 4 weeks) were asked whether they would be interested in participating in an online support AF community. Mobile users (owns smartphone and/or tablet) were asked about interest in communicating with their health care team about their AF-related health using a secure app. Logistic regression models identified crude and multivariable predictors of Facebook use and interest in digital disease support. RESULTS: Online patients (N=816) were aged 74.2 (SD 6.6) years, 47.8% (390/816) were female, and 91.1% (743/816) were non-Hispanic white. Roughly half (52.5%; 428/816) used Facebook. Facebook use was more common among women (adjusted odds ratio [aOR] 2.21, 95% CI 1.66-2.95) and patients with mild to severe depressive symptoms (aOR 1.50, 95% CI 1.08-2.10) and less common among patients aged \u3e /=85 years (aOR 0.27, 95% CI 0.15-0.48). Forty percent (40.4%; 330/816) reported interest in an online AF patient community. Interest in an online AF patient community was more common among online patients with some college/trade school or Bachelors/graduate school (aOR 1.70, 95% CI 1.10-2.61 and aOR 1.82, 95% CI 1.13-2.92, respectively), obesity (aOR 1.65, 95% CI 1.08-2.52), online health information seeking at most weekly or multiple times per week (aOR 1.84, 95% CI 1.32-2.56 and aOR 2.78, 95% CI 1.86-4.16, respectively), and daily Facebook use (aOR 1.76, 95% CI 1.26-2.46). Among mobile users, 51.8% (324/626) reported interest in communicating with their health care team via a mobile app. Interest in app-mediated communication was less likely among women (aOR 0.48, 95% CI 0.34-0.68) and more common among online patients who had completed trade school/some college versus high school/General Educational Development (aOR 1.95, 95% CI 1.17-3.22), sought online health information at most weekly or multiple times per week (aOR 1.86, 95% CI 1.27-2.74 and aOR 2.24, 95% CI 1.39-3.62, respectively), and had health-related apps (aOR 3.92, 95% CI 2.62-5.86). CONCLUSIONS: Among older adults with AF who use the internet, technology use and demographics are associated with interest in digital disease support. Clinics and health care providers may wish to encourage patients to join an existing online support community for AF and explore opportunities for app-mediated patient-provider communication

    Unmaking citizens: passport removals, pre-emptive policing and the reimagining of colonial governmentalities

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    With the intensifying securitization of Western borders in the global War on Terror citizenship rights are increasingly fragile. Measures introduced by the British government to deal with the terrorist threat at home include citizenship deprivation, temporary exclusion orders as well as passport removals. Whilst citizenship deprivation has provoked critique for its potential violations of international human rights conventions on statelessness, cancellations of passports have not been subjected to the same kind of critique. Drawing on recent debates and interview data we demonstrate the alignment of citizenship deprivation and passport removals and conclude that these measures serve the same goal: of unmaking citizens. In this paper, we discuss findings from novel empirical research with individuals who have been removed of their British passports to illuminate the racialized dynamics of this process and the reconfiguration of racial governmentalities
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