117 research outputs found
Online and offline heuristics for inferring hierarchies of repetitions in sequences
Hierarchical dictionary-based compression schemes form a grammar for a text by replacing each repeated string with a production rule. While such schemes usually operate online, making a replacement as soon as repetition is detected, offline operation permits greater freedom in choosing the order of replacement. In this paper, we compare the online method with three offline heuristics for selecting the next substring to replace: longest string first, most common string first, and the string that minimized the size of the grammar locally. Surprisingly, two of the offline techniques, like the online method, run in time linear in the size of the input. We evaluate each technique on artificial and natural sequences. In general, the locally-most-compressive heuristic performs best, followed by most frequent, the online technique, and, lagging by some distance, the longest-first technique
Kv7/M-type potassium channels in rat skin keratinocytes.
Skin keratinocytes fulfil important signalling and protective functions. Immunocytochemical experiments revealed the unexpected presence of immunoreactivity for the M-type potassium channel subunit Kv7.2 in the keratinocyte layer of intact rat paw skin and in keratinocytes isolated from the skin of 1-day-old rats and cultured in vitro for 3-10 days. Application of the M-channel enhancer retigabine (3-10 μM) to isolated cultured rat keratinocytes: (a) increased outward membrane currents recorded under voltage clamp, (b) produced ~3 mV hyperpolarization at rest, (c) enhanced ~3-fold the release of ATP induced by the TRPV3 agonist carvacrol (1 mM) and (d) increased the amplitude of the carvacrol-induced intracellular Ca(2+) transient measured with Fura-2. The effect of retigabine on ATP release was prevented by the M-channel blocking agent XE991. We conclude that rat skin keratinocytes possess M-channels that, when activated, can modify their physiological properties, with potential significance for their sensory and other biological functions
KCNQ/M currents in sensory neurons: Significance for pain therapy
Neuronal hyperexcitability is a feature of epilepsy and both inflammatory and neuropathic pain. M currents [I-K(M)] play a key role in regulating neuronal excitability, and mutations in neuronal KCNQ2/3 subunits, the molecular correlates of I-K(M), have previously been linked to benign familial neonatal epilepsy. Here, we demonstrate that KCNQ/M channels are also present in nociceptive sensory systems. I-K(M) was identified, on the basis of biophysical and pharmacological properties, in cultured neurons isolated from dorsal root ganglia (DRGs) from 17-d-old rats. Currents were inhibited by the M-channel blockers linopirdine (IC50, 2.1 muM) and XE991 (IC50, 0.26 muM) and enhanced by retigabine (10 muM). The expression of neuronal KCNQ subunits in DRG neurons was confirmed using reverse transcription-PCR and single-cell PCR analysis and by immunofluorescence. Retigabine, applied to the dorsal spinal cord, inhibited C and Adelta fiber-mediated responses of dorsal horn neurons evoked by natural or electrical afferent stimulation and the progressive "windup" discharge with repetitive stimulation in normal rats and in rats subjected to spinal nerve ligation. Retigabine also inhibited responses to intrapaw application of carrageenan in a rat model of chronic pain; this was reversed by XE991. It is suggested that I-K(M) plays a key role in controlling the excitability of nociceptors and may represent a novel analgesic target
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Become the best coach you can be: the role of coach training and coaching experience in workplace coaching quality and quality control
This paper explores whether coach training or coaching experience leads to better coaching quality and quality control. In two large studies, both coaches (N1 = 2267) and personnel managers who book coaches for their company (N2 = 754) answered questions about coaching quality and quality control. The results show that more coach training leads to not only a better self-perceived coaching quality (Study 1) but also a better other-perceived coaching-quality (Study 2); moreover, more coach training positively affects quality control. It is remarkable that coaching experience showed no significant relation regarding other-perceived coaching quality and quality control. Study 2 further revealed that references lead to more recommendations but not to a better coaching quality or quality control. Thus, coach training is an essential factor when selecting organizational coaches. Further research is needed to understand the impact of different approaches to coach trainings on coaching outcomes
Predicting the location of the hip joint centres, impact of age group and sex
Clinical gait analysis incorporating three-dimensional motion analysis plays a key role in planning surgical treatments in people with gait disability. The position of the Hip Joint Centre (HJC) within the pelvis is thus critical to ensure accurate data interpretation. The position of the HJC is determined from regression equations based on anthropometric measurements derived from relatively small datasets. Current equations do not take sex or age into account, even though pelvis shape is known to differ between sex, and gait analysis is performed in populations with wide range of age. Three dimensional images of 157 deceased individuals (37 children, 120 skeletally matured) were collected with computed tomography. The location of the HJC within the pelvis was determined and regression equations to locate the HJC were developed using various anthropometrics predictors. We determined if accuracy improved when age and sex were introduced as variables. Statistical analysis did not support differentiating the equations according to sex. We found that age only modestly improved accuracy. We propose a range of new regression equations, derived from the largest dataset collected for this purpose to date
Conserved CDC20 Cell Cycle Functions Are Carried out by Two of the Five Isoforms in Arabidopsis thaliana
The CDC20 and Cdh1/CCS52 proteins are substrate determinants and activators of the Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligase and as such they control the mitotic cell cycle by targeting the degradation of various cell cycle regulators. In yeasts and animals the main CDC20 function is the destruction of securin and mitotic cyclins. Plants have multiple CDC20 gene copies whose functions have not been explored yet. In Arabidopsis thaliana there are five CDC20 isoforms and here we aimed at defining their contribution to cell cycle regulation, substrate selectivity and plant development.Studying the gene structure and phylogeny of plant CDC20s, the expression of the five AtCDC20 gene copies and their interactions with the APC/C subunit APC10, the CCS52 proteins, components of the mitotic checkpoint complex (MCC) and mitotic cyclin substrates, conserved CDC20 functions could be assigned for AtCDC20.1 and AtCDC20.2. The other three intron-less genes were silent and specific for Arabidopsis. We show that AtCDC20.1 and AtCDC20.2 are components of the MCC and interact with mitotic cyclins with unexpected specificity. AtCDC20.1 and AtCDC20.2 are expressed in meristems, organ primordia and AtCDC20.1 also in pollen grains and developing seeds. Knocking down both genes simultaneously by RNAi resulted in severe delay in plant development and male sterility. In these lines, the meristem size was reduced while the cell size and ploidy levels were unaffected indicating that the lower cell number and likely slowdown of the cell cycle are the cause of reduced plant growth.The intron-containing CDC20 gene copies provide conserved and redundant functions for cell cycle progression in plants and are required for meristem maintenance, plant growth and male gametophyte formation. The Arabidopsis-specific intron-less genes are possibly "retrogenes" and have hitherto undefined functions or are pseudogenes
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Co-regulation map of the human proteome enables identification of protein functions
This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData availability:
All mass spectrometry raw files generated in-house have been deposited in the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository36 with the dataset identifier PXD008888. The co-regulation map is hosted on our website at www.proteomeHD.net, and pair-wise co-regulation scores are available through STRING (https://string-db.org). A network of the top 0.5% co-regulated protein pairs can be explored interactively on NDEx (https://doi.org/10.18119/N9N30Q).Code availability:
Data analysis was performed in R 3.5.1. R scripts and input files required to reproduce the results of this manuscript are available in the following GitHub repository: https://github.com/Rappsilber-Laboratory/ProteomeHD. R scripts related specifically to the benchmarking of the treeClust algorithm using synthetic data are available in the following GitHub repository: https://github.com/Rappsilber-Laboratory/treeClust-benchmarking. The R package data.table was used for fast data processing. Figures were prepared using ggplot2, gridExtra, cowplot and viridis.Note that the title of the AAM is different from the published versionThe annotation of protein function is a longstanding challenge of cell biology that
suffers from the sheer magnitude of the task. Here we present ProteomeHD, which
documents the response of 10,323 human proteins to 294 biological perturbations,
measured by isotope-labelling mass spectrometry. We reveal functional associations
between human proteins using the treeClust machine learning algorithm, which we
show to improve protein co-regulation analysis due to robust selectivity for close
linear relationships. Our co-regulation map identifies a functional context for many
uncharacterized proteins, including microproteins that are difficult to study with
traditional methods. Co-regulation also captures relationships between proteins
which do not physically interact or co-localize. For example, co-regulation of the
peroxisomal membrane protein PEX11β with mitochondrial respiration factors led us
to discover a novel organelle interface between peroxisomes and mitochondria in
mammalian cells. The co-regulation map can be explored at www.proteomeHD.net .Biotechnology & Biological Sciences Research Council (BBSRC)European Commissio
Local Translation in Primary Afferent Fibers Regulates Nociception
Recent studies have demonstrated the importance of local protein synthesis for neuronal plasticity. In particular, local mRNA translation through the mammalian target of rapamycin (mTOR) has been shown to play a key role in regulating dendrite excitability and modulating long-term synaptic plasticity associated with learning and memory. There is also increased evidence to suggest that intact adult mammalian axons have a functional requirement for local protein synthesis in vivo. Here we show that the translational machinery is present in some myelinated sensory fibers and that active mTOR-dependent pathways participate in maintaining the sensitivity of a subpopulation of fast-conducting nociceptors in vivo. Phosphorylated mTOR together with other downstream components of the translational machinery were localized to a subset of myelinated sensory fibers in rat cutaneous tissue. We then showed with electromyographic studies that the mTOR inhibitor rapamycin reduced the sensitivity of a population of myelinated nociceptors known to be important for the increased mechanical sensitivity that follows injury. Behavioural studies confirmed that local treatment with rapamycin significantly attenuated persistent pain that follows tissue injury, but not acute pain. Specifically, we found that rapamycin blunted the heightened response to mechanical stimulation that develops around a site of injury and reduced the long-term mechanical hypersensitivity that follows partial peripheral nerve damage - a widely used model of chronic pain. Our results show that the sensitivity of a subset of sensory fibers is maintained by ongoing mTOR-mediated local protein synthesis and uncover a novel target for the control of long-term pain states
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