Homology to peptide pattern for annotation of carbohydrate-active enzymes and prediction of function.

BACKGROUND: Carbohydrate-active enzymes are found in all organisms and participate in key biological processes. These enzymes are classified in 274 families in the CAZy database but the sequence diversity within each family makes it a major task to identify new family members and to provide basis for prediction of enzyme function. A fast and reliable method for de novo annotation of genes encoding carbohydrate-active enzymes is to identify conserved peptides in the curated enzyme families followed by matching of the conserved peptides to the sequence of interest as demonstrated for the glycosyl hydrolase and the lytic polysaccharide monooxygenase families. This approach not only assigns the enzymes to families but also provides functional prediction of the enzymes with high accuracy. RESULTS: We identified conserved peptides for all enzyme families in the CAZy database with Peptide Pattern Recognition. The conserved peptides were matched to protein sequence for de novo annotation and functional prediction of carbohydrate-active enzymes with the Hotpep method. Annotation of protein sequences from 12 bacterial and 16 fungal genomes to families with Hotpep had an accuracy of 0.84 (measured as F1-score) compared to semiautomatic annotation by the CAZy database whereas the dbCAN HMM-based method had an accuracy of 0.77 with optimized parameters. Furthermore, Hotpep provided a functional prediction with 86% accuracy for the annotated genes. Hotpep is available as a stand-alone application for MS Windows. CONCLUSIONS: Hotpep is a state-of-the-art method for automatic annotation and functional prediction of carbohydrate-active enzymes.

Phenylephrine increases near-infrared spectroscopy determined muscle oxygenation in men.

Phenylephrine increases mean arterial pressure (MAP) by enhanced total peripheral resistance (TPR) but near-infrared spectroscopy (NIRS) determined muscle oxygenation (SmO2) increases. We addressed that apparent paradox during supine rest and head-up tilt (HUT). Variables were determined ± phenylephrine in males during supine rest (n = 17) and 40° HUT (n = 7). MAP, stroke volume (SV), heart rate (HR), and TPR were derived by Modelflow® and NIRS determined biceps SmO2 and (tibial) bone oxygenation (StibialO2). For ten subjects, cardiac filling and the diameter of the inferior caval vein (ICV collapsibility index: ((ICVexpiration - ICVinspiration)/ICVexpiration) × 100) were assessed by ultrasound. Pancreatic polypeptide (PP) and atrial natriuretic peptide (proANP) in plasma were determined by immunoassay. Brachial artery blood flow was assessed by ultrasound and skin oxygenation (SskinO2) monitored by white light spectroscopy. Phenylephrine increased MAP by 34% and TPR (62%; P < 0.001) during supine rest. The ICV collapsibility index decreased (24%; P < 0.001) indicating augmented cardiac preload although volume of the left atrium and ventricle did not change. SV increased (18%; P < 0.001) as HR decreased (24%; P < 0.001). ProANP increased by 9% (P = 0.002) with unaffected PP. Brachial artery blood flow tended to decrease while SskinO2 together with StibialO2 decreased by 11% (P = 0.026) and 20% (P < 0.001), respectively. Conversely, phenylephrine increased SmO2 (9%) and restored the HUT elicited decrease in SmO2 (by 19%) along with SV (P = 0.02). Phenylephrine reduces skin and bone oxygenation and tends to reduce arm blood flow, suggesting that the increase in SmO2 reflects veno-constriction with consequent centralization of the blood volume.

Assessing Effects and interactions among key variables affecting the growth of mixotrophic microalgae: pH, inoculum volume, and growth medium composition.

A 2(3) + 3 full factorial experimental design was used to evaluate growth rate and biomass productivity of four selected, high-biomass-yielding microalgae species,namely, Chlorella vulgaris (CV), Scenedesmus acutus (SA), Chlamydomonas reinhardtii (CR), and Chlamydomonas debaryana (CD), in mixtures of growth medium (MWC) and wastewater at different proportions (from 20 to 50% of MWC) and at different pH (from 7 to 9). Multilinear regression analysis of the biomass productivity data showed that for SA and CD the biomass productivity was independent of the proportion of medium (MWC), while the growth of CV and CR slowed down in mixtures with high proportions of wastewater. However, the biomass productivity of SA was dependent on pH, while the growth of the other microalgae was independent of pH (7-9). When evaluating the influence of pH and proportion of medium, CD appeared most robust among the algae species, despite its lower biomass productivity. All the four species reduced 80-90% of the nitrate [Formula: see text] and 60-70% of the ammonia [Formula: see text] initially present in the wastewater:medium mixture, although the extent of the reduction was dependent on the initial [Formula: see text] ratio. Both SA and CV reduced ∼20-25% of the chemical oxygen demand (COD) contained in the wastewater. This study shows the remarkable influence of certain variables that are often ignored in the search for optimal conditions of microalgal growth and also reveals the importance of considering interactions among growth variables in potential applications at large scale, particularly in the field of bioremediation.

The Next Food Revolution Is Here: Recombinant Microbial Production of Milk and Egg Proteins by Precision Fermentation.

Animal-based agriculture and the production of protein-rich foods from animals, particularly from ruminants, are not sustainable and have serious climate effects. A new type of alternative proteins is now on the menu, namely animal proteins produced recombinantly by microbial fermentation. This new technology, precision fermentation, is projected to completely disrupt traditional animal-based agriculture. Certain milk and egg proteins along with specific meat substitute analog components produced by precision fermentation are already entering the market. This first wave of precision fermentation products targets the use of these proteins as protein additives, and several commercial players are already active in the field. The cost-efficiency requirements involve production titers above 50 g/L which are several orders of magnitude higher than those for pharmaceutical protein manufacture, making strain engineering, process optimization, and scale-up critical success factors. This new development within alternative proteins defines a new research direction integrating biotechnology, process engineering, and sustainable food protein production.

[Application of digital pathology tools. An unusual case of non-Hodgkin lymphoma]. / Anwendung von Verfahren der digitalen Pathologie. Fallbeispiel eines ungewöhnlichen Non-Hodgkin-Lymphoms.

Currently, lymphoma diagnosis is based on a combination of morphology, immunophenotyping, and molecular testing. Using the example of an unusual case of malignant non-Hodgkin lymphoma, we show that improved visualization using digital pathology contributes to the convergence of these complementary diagnostic modalities. A 45-year-old woman presented with skin rash and cervical lymphadenopathy. Histological workup of an excised lymph node showed loss of normal architecture with diffuse infiltration and increased mitotic activity. Immunohistochemistry for CD3/CD5 showed atypical arrangement and infiltration of a T-cell population that dominated over regionally dense, MUM1-positive plasmacellular infiltrates. Expanded CD21/CD23-positive meshworks of follicular dendritic cells were present within and between regressed follicles and the T-cell infiltrate; staining for CD56 and cyclin-D1 was negative. Quantification of Ki-67 staining within the T-, B- and plasmacellular compartments was achieved by digital image conversion, overlay and subsequent quantification algorithms that revealed proliferation within more than 60% of T-cells, over 50% of plasma cells and only 20% of B-cells. Clonality analysis by PCR revealed monoclonal rearrangement for both T-cell receptor gamma chains and immunoglobulin heavy chains. Taken together, we present an unusual combination of an angioimmunoblastic T-cell lymphoma (AITL) and simultaneous plasmacellular lymphoma. This report demonstrates how application of modern tools of digital pathology can visually integrate unusual morphological and molecular findings.

Bank of Standardized Stimuli (BOSS): Dutch Names for 1400 Photographs.

We present written naming norms from 153 young adult Dutch speakers for 1397 photographs (the BOSS set; see Brodeur, Dionne-Dostie, Montreuil, & Lepage, 2010; Brodeur, Guérard, & Bouras, 2014). From the norming study, we report the preferred (modal) name, alternative names, name agreement, and average object agreement. In addition, the data base includes Zipf frequency, word prevalence and Age of Acquisition for the modal picture names collected. Furthermore, we describe a subset of 359 photographs with very good name agreement and a subset of 35 photos with two common names. These sets may be particularly valuable for designing experiments. Though the participants typed the object names, comparisons with other datasets indicate that the collected norms are valuable for spoken naming studies as well.

Synthesis of N-Acetyllactosamine and N-Acetyllactosamine-Based Bioactives.

N-Acetyllactosamine (LacNAc) or more specifically ß-d-galactopyranosyl-1,4-N-acetyl-d-glucosamine is a unique acyl-amino sugar and a key structural unit in human milk oligosaccharides, an antigen component of many glycoproteins, and an antiviral active component for the development of effective drugs against viruses. LacNAc is useful itself and as a basic building block for producing various bioactive oligosaccharides, notably because this synthesis may be used to add value to dairy lactose. Despite a significant amount of information in the literature on the benefits, structures, and types of different LacNAc-derived oligosaccharides, knowledge about their effective synthesis for large-scale production is still in its infancy. This work provides a comprehensive analysis of existing production strategies for LacNAc and important LacNAc-based structures, including sialylated LacNAc as well as poly- and oligo-LacNAc. We conclude that direct extraction from milk is too complex, while chemical synthesis is also impractical at an industrial scale. Microbial routes have application when multiple step reactions are needed, but the major route to large-scale biochemical production will likely lie with enzymatic routes, particularly those using ß-galactosidases (for LacNAc synthesis), sialidases (for sialylated LacNAc synthesis), and ß-N-acetylhexosaminidases (for oligo-LacNAc synthesis). Glycosyltransferases, especially for the biosynthesis of extended complex LacNAc structures, could also play a major role in the future. In these cases, immobilization of the enzyme can increase stability and reduce cost. Processing parameters, such as substrate concentration and purity, acceptor/donor ratio, water activity, and temperature, can affect product selectivity and yield. More work is needed to optimize these reaction parameters and in the development of robust, thermally stable enzymes to facilitate commercial production of these important bioactive substances.

Low dose Iloprost effect on platelet aggregation in comatose out-of-hospital cardiac arrest patients: A predefined sub-study of the ENDO-RCA randomized -phase 2- trial.

PURPOSE: This is a predefined sub-study of the Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA) trial. We aim to investigate Iloprost, a prostacyclin analogue, safety by evaluating change in whole blood platelet aggregometry (Multiplate) in out of hospital cardiac arrest (OHCA) patients from baseline to 96-h post randomization. METHODS: A randomized, placebo controlled double-blinded trial in 46 OHCA patients. Patients were allocated 1:2 to 48 h Iloprost infusion, (1 ng/kg/min) or placebo (saline infusion). Platelet aggregation was determined by platelet aggregation tests ASPI-test (arachidonic acid); TRAP-test (thrombin-receptor activating peptide (TRAP)-6; RISTO test (Ristocetin); ADP test (adenosin diphosphat). RESULTS: There was no significant difference between the iloprost and placebo groups according to ASPI, TRAP, RISTO and ADP platelet aggregation assays. Further, no significant differences regarding risk of bleeding were found between groups (Risk of bleeding: ASPI <40 U; TRAP <92 U; RISTO <35 U; ADP <50 U). CONCLUSIONS: In conclusion, the iloprost infusion did not influence platelet aggregation as evaluated by the ASPI, TRAP, RISTO and ADP assays. There was no increased risk of bleeding or transfusion therapy. A decline in platelet aggregation was observed for the ASPI and ADP assays during the initial 96 h after OHCA. TRIAL REGISTRATION: Trial registration at clinicaltrials.gov (identifier NCT02685618) on 18-02-2016.

Separate and simultaneous enzymatic hydrolysis and fermentation of wheat hemicellulose with recombinant xylose utilizing Saccharomyces cerevisiae.

Fermentations with three different xylose-utilizing recombinant Saccharomyces cerevisiae strains (F12, CR4, and CB4) were performed using two different wheat hemicellulose substrates, unfermented starch free fibers, and an industrial ethanol fermentation residue, vinasse. With CR4 and F12, the maximum ethanol concentrations obtained were 4.3 and 4 g/L, respectively, but F12 converted xylose 15% faster than CR4 during the first 24 h. The comparison of separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) with F12 showed that the highest, maximum ethanol concentrations were obtained with SSF In general, the volumetric ethanol productivity was initially, highest in the SHF, but the overall volumetric ethanol productivity ended up being maximal in the SSF, at 0.013 and 0.010 g/Lh, with starch free fibers and vinasse, respectively.

In contrast to glucocorticoid receptors, mineralocorticoid receptors are not autoregulated in rat distal colon epithelia.

Glucocorticoids and mineralocorticoids exert profound effects on electrolyte balance in the rat distal colon by binding with high affinity and specificity to intracellular receptor proteins, termed glucocorticoid (GR) and mineralocorticoid (MR) receptors, respectively. Hormonal regulation of GR and MR expression represents an important mechanism for maintaining appropriate tissue sensitivity to these two classes of adrenocorticosteroids. In the present study the corticosteroid regulation of the expression of these two rat colonic receptors has been evaluated at the protein and mRNA levels. Preliminary experiments demonstrated that colonic MR and GR binding levels are significantly increased (approximately 60%) after adrenalectomy (14 days). Experiments were therefore performed to test the hypothesis that these increases in binding levels correlate with increased GR and MR mRNA and protein levels. Receptor mRNA levels were quantitated via ribonuclease protection assays using [32P]cRNA probes specific for either GR or MR mRNA, and GR and MR protein levels were quantitated via Western immunoblotting using the anti-GR BuGR2 and anti-MR hMRsN antibodies. Fourteen days after adrenalectomy, significant increases in GR mRNA (2.1-fold) and protein levels (1.6-fold) were detected. In contrast, neither MR mRNA nor protein levels were up-regulated by removal of endogenous corticosteroids. Additionally, GR and MR mRNA levels were measured after ip injection of adrenalectomized rats with pharmacological doses of either the pure glucocorticoid agonist RU 28362 or the mineralocorticoid agonist aldosterone in combination with the glucocorticoid antagonist RU 38486 (blocks aldosterone binding to the GR). Multiple ip injections of RU 28362 resulted in a significant decrease (80%) in GR mRNA levels without affecting MR mRNA levels. In contrast, multiple ip injections of aldosterone (plus RU 38486) had no effect on either MR or GR mRNA levels. A single ip injection of RU 28362 resulted in a detectable decrease (30%) in GR mRNA levels and again had no effect on MR mRNA levels. Although a single ip injection of aldosterone did not down-regulate MR mRNA levels, it did elicit a significant decrease (45%) in GR mRNA levels. Taken collectively, these data demonstrate that rat colonic GR and MR mRNA and protein levels are differentially up-regulated after removal of endogenous corticosteroids. Additionally, these data demonstrate that in response to its cognate ligand, the GR is capable of homologously down-regulating its own mRNA and protein levels. However, in response to its cognate ligand, the MR appears incapable of homologously down-regulating its own mRNA levels.(ABSTRACT TRUNCATED AT 400 WORDS)

Potentiation of glucocorticoid-induced cytolysis in sensitive human leukemic cells by an inhibitor of ADP-ribosylation.

3-Aminobenzamide, a general inhibitor of poly(ADP-ribose)polymerase, potentiated the triamcinolone acetonide-mediated growth inhibition and lysis of the glucocorticoid-sensitive CEM-C7 human leukemic cell line. This potentiation was dose-dependent with maximal response being detected at 3 mM 3-aminobenzamide, and was completely blocked by the glucocorticoid receptor antagonist RU 38486. Scatchard analysis of whole cell specific [3H]triamcinolone acetonide binding data did not reveal any effect of 3-aminobenzamide on either the number of intracellular receptor binding sites or their affinity for the agonist. Treatment of the ICR-27 cell line, which is a glucocorticoid resistant mutant isolated from CEM-C7, with 3-aminobenzamide did not restore triamcinolone acetonide sensitivity. Similarly, 3-aminobenzamide treatment of several other lymphoid cell lines (human HL60 and IM-9 and murine L1210 cells) which contain functional receptors but are not normally lysed by glucocorticoid agonists, failed to induce sensitivity to triamcinolone acetonide. Since treatment of sensitive lymphoid cells with glucocorticoid agonists results in DNA fragmentation prior to cell death, these data suggest that 3-aminobenzamide potentiates the cytolytic response of sensitive cells to glucocorticoid agonists by inhibiting DNA excision repair mechanisms.

Investigation of phonological encoding through speech error analyses: achievements, limitations, and alternatives.

Phonological encoding in language production can be defined as a set of processes generating utterance forms on the basis of semantic and syntactic information. Most evidence about these processes stems from analyses of sound errors. In section 1 of this paper, certain important results of these analyses are reviewed. Two prominent models of phonological encoding, which are mainly based on speech error evidence, are discussed in section 2. In section 3, limitations of speech error analyses are discussed, and it is argued that detailed and comprehensive models of phonological encoding cannot be derived solely on the basis of error analyses. As is argued in section 4, a new research strategy is required. Instead of using the properties of errors to draw inferences about the generation of correct word forms, future research should directly investigate the normal process of phonological encoding.

A case for the lemma/lexeme distinction in models of speaking: comment on Caramazza and Miozzo (1997)

In a recent series of papers, Caramazza and Miozzo [Caramazza, A., 1997. How many levels of processing are there in lexical access? Cognitive Neuropsychology 14, 177-208; Caramazza, A., Miozzo, M., 1997. The relation between syntactic and phonological knowledge in lexical access: evidence from the 'tip-of-the-tongue' phenomenon. Cognition 64, 309-343; Miozzo, M., Caramazza, A., 1997. On knowing the auxiliary of a verb that cannot be named: evidence for the independence of grammatical and phonological aspects of lexical knowledge. Journal of Cognitive Neuropsychology 9, 160-166] argued against the lemma/lexeme distinction made in many models of lexical access in speaking, including our network model [Roelofs, A., 1992. A spreading-activation theory of lemma retrieval in speaking. Cognition 42, 107-142; Levelt, W.J.M., Roelofs, A., Meyer, A.S., 1998. A theory of lexical access in speech production. Behavioral and Brain Sciences, (in press)]. Their case was based on the observations that grammatical class deficits of brain-damaged patients and semantic errors may be restricted to either spoken or written forms and that the grammatical gender of a word and information about its form can be independently available in tip-of-the-tongue states (TOTs). In this paper, we argue that though our model is about speaking, not taking position on writing, extensions to writing are possible that are compatible with the evidence from aphasia and speech errors. Furthermore, our model does not predict a dependency between gender and form retrieval in TOTs. Finally, we argue that Caramazza and Miozzo have not accounted for important parts of the evidence motivating the lemma/lexeme distinction, such as word frequency effects in homophone production, the strict ordering of gender and phoneme access in LRP data, and the chronometric and speech error evidence for the production of complex morphology.

Lexical access in the production of pronouns.

Speakers can use pronouns when their conceptual referents are accessible from the preceding discourse, as in 'The flower is red. It turns blue'. Theories of language production agree that in order to produce a noun semantic, syntactic, and phonological information must be accessed. However, little is known about lexical access to pronouns. In this paper, we propose a model of pronoun access in German. Since the forms of German pronouns depend on the grammatical gender of the nouns they replace, the model claims that speakers must access the syntactic representation of the replaced noun (its lemma) to select a pronoun. In two experiments using the lexical decision during naming paradigm [Levelt, W.J.M., Schriefers, H., Vorberg, D., Meyer, A.S., Pechmann, T., Havinga, J., 1991a. The time course of lexical access in speech production: a study of picture naming. Psychological Review 98, 122-142], we investigated whether lemma access automatically entails the activation of the corresponding word form or whether a word form is only activated when the noun itself is produced, but not when it is replaced by a pronoun. Experiment 1 showed that during pronoun production the phonological form of the replaced noun is activated. Experiment 2 demonstrated that this phonological activation was not a residual of the use of the noun in the preceding sentence. Thus, when a pronoun is produced, the lemma and the phonological form of the replaced noun become reactivated.

Viewing and naming objects: eye movements during noun phrase production.

Eye movements have been shown to reflect word recognition and language comprehension processes occurring during reading and auditory language comprehension. The present study examines whether the eye movements speakers make during object naming similarly reflect speech planning processes. In Experiment 1, speakers named object pairs saying, for instance, 'scooter and hat'. The objects were presented as ordinary line drawings or with partly deleted contours and had high or low frequency names. Contour type and frequency both significantly affected the mean naming latencies and the mean time spent looking at the objects. The frequency effects disappeared in Experiment 2, in which the participants categorized the objects instead of naming them. This suggests that the frequency effects of Experiment 1 arose during lexical retrieval. We conclude that eye movements during object naming indeed reflect linguistic planning processes and that the speakers' decision to move their eyes from one object to the next is contingent upon the retrieval of the phonological form of the object names.

Differential effects of agonist and antagonists on autoregulation of glucocorticoid receptors in a rat colonic adenocarcinoma cell line.

The relative abilities of a potent glucocorticoid receptor (GR) agonist (RU 28362), a weak GR agonist (aldosterone) and a potent GR antagonist (RU 38486) to promote in vivo activation/transformation and subsequent down-regulation of GR mRNA and protein levels were compared using the PROb rat colonic adenocarcinoma cell line. In vivo activation, which is followed immediately by nuclear translocation, by these ligands (1 microM) was evaluated in terms of their abilities to deplete cytoplasmic GR protein levels after a 30 min incubation period. Western blotting experiments with the anti-GR monoclonal antibody BuGR2 demonstrated that a brief incubation with RU 28362 resulted in nearly complete depletion of cytoplasmic GR, whereas incubation with aldosterone resulted in a 50% depletion of the cytoplasmic GR protein. Incubation with RU 38486 was even more effective than aldosterone in promoting this key step in the GR pathway. Prolonged treatment (18 h) with RU 28362 resulted in significant down-regulation of GR mRNA and total cellular GR protein levels. Similar incubation with aldosterone resulted in a transient decrease in the GR mRNA level and also down-regulated the total GR protein level. Although prolonged incubation with RU 38486 did not result in detectable down-regulation of the GR mRNA level, this antagonist very effectively down-regulated total cellular GR protein levels. Taken collectively, these data demonstrate that agonists capable of promoting in vivo activation (and subsequent nuclear translocation) of GR are also effective at down-regulating GR at both the mRNA and protein levels. Although the antagonist RU 38486 is also capable of down-regulating GR protein levels by shortening the half-life of the receptor, it appears to be incapable of altering the rate of transcription of the GR gene. Glucocorticoid target tissue sensitivity may thus be decreased via two independent mechanisms: agonist-induced repression of GR gene transcription; and/or ligand-induced degradation of total cellular GR protein levels.

Potential mechanisms underlying autoregulation of glucocorticoid receptor mRNA levels in the DHD/K12/PROb rat colonic adenocarcinoma cell line.

The DHD/K12/PROb rat colonic epithelial cell line, which was originally derived from a chemically induced adenocarcinoma, expresses functional glucocorticoid receptors (GR) and has been reported to be growth inhibited by glucocorticoid agonists. In the present study the potential mechanisms underlying corticosteroid-mediated autoregulation of GR mRNA levels in this colonic cell line were investigated. The GR mRNA levels in the various treatment groups were quantitated via the ribonuclease protection assay using a specific 32P-cRNA probe. Time-course experiments demonstrated that in contrast to several other cell lines that are also growth inhibited by glucocorticoids, treatment of confluent monolayers of PROb cells with the pure GR agonist RU 28362 (1 microM) elicits a rapid and significant (65%) down-regulation of GR mRNA levels that is sustained for at least 36 h. This down-regulation, which is also elicited to a lesser extent by weaker GR agonists including corticosterone and aldosterone, is blocked by the GR antagonist RU 38486. The protein synthesis inhibitor cycloheximide was utilized to demonstrate that the initial phase (6 h) of agonist-mediated down-regulation occurs independently of ongoing protein synthesis, although new protein synthesis, perhaps of the GR protein itself, is required to maintain this down-regulation. Although agonist-mediated down-regulation in these cells probably occurs primarily at the level of GR gene transcription, inhibition of ongoing RNA synthesis with actinomycin D or 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) demonstrated that during the initial phase (1 h) of this down-regulation, but not following maximal (18 h) down-regulation, RU 28362 treatment also significantly reduces the stability of the GR mRNA.

Speech errors, phonotactic constraints, and implicit learning: a study of the role of experience in language production.

Speech errors follow the phonotactics of the language being spoken. For example, in English, if [n] is mispronounced as [n], the [n] will always appear in a syllable coda. The authors created an analogue to this phenomenon by having participants recite lists of consonant-vowel-consonant syllables in 4 sessions on different days. In the first 2 experiments, some consonants were always onsets, some were always codas, and some could be both. In a third experiment, the set of possible onsets and codas depended on vowel identity. In all 3 studies, the production errors that occurred respected the "phonotactics" of the experiment. The results illustrate the implicit learning of the sequential constraints present in the stimuli and show that the language production system adapts to recent experience.