There are growing concerns about irrational antibiotic prescription practices in the era of test-based malaria case management. This study assessed integrated paediatric fever management using malaria rapid diagnostic tests (RDT) and Integrated Management of Childhood Illness (IMCI) guidelines, including the relationship between RDT-negative results and antibiotic over-treatment in Malawi health facilities in 2013–2014.A Malawi national facility census included 1981 observed sick children aged 2–59 months with fever complaints. Weighted frequencies were tabulated for other complaints, assessments and prescriptions for RDT-confirmed malaria, IMCI-classified non-severe pneumonia, and clinical diarrhoea. Classification trees using model-based recursive partitioning estimated the association between RDT results and antibiotic over-treatment and learned the influence of 38 other input variables at patient-, provider- and facility-levels.Among 1981 clients, 72 % were tested or referred for malaria diagnosis and 85 % with RDT-confirmed malaria were prescribed first-line anti-malarials. Twenty-eight percent with IMCI-pneumonia were not prescribed antibiotics (under-treatment) and 59 % ‘without antibiotic need’ were prescribed antibiotics (over-treatment). Few clients had respiratory rates counted to identify antibiotic need for IMCI-pneumonia (18 %). RDT-negative children had 16.8 (95 % CI 8.6–32.7) times higher antibiotic over-treatment odds compared to RDT-positive cases conditioned by cough or difficult breathing complaints.Integrated paediatric fever management was sub-optimal for completed assessments and antibiotic targeting despite common compliance to malaria treatment guidelines. RDT-negative results were strongly associated with antibiotic over-treatment conditioned by cough or difficult breathing complaints. A shift from malaria-focused ‘test and treat’ strategies toward ‘IMCI with testing’ is needed to improve quality fever care and rational use of both anti-malarials and antibiotics in line with recent global commitments to combat resistance.The online version of this article (doi:10.1186/s12936-016-1439-7) contains supplementary material, which is available to authorized users. Since the 1990s, the World Health Organization (WHO) and United Nations Children’s Fund (UNICEF) have promoted the Integrated Management of Childhood Illness (IMCI) strategy in low- and middle-income countries to effectively manage the most common causes of child morbidity and mortality in an integrated manner .Fever is a common symptom of many childhood illnesses in sub-Saharan Africa. For many years however, the IMCI strategy promoted presumptive malaria treatment of paediatric fevers in malaria-endemic African settings given high malaria mortality rates and the lack of other defining features for clinical management. While additional IMCI algorithms have been available to clinically differentiate other fever causes, the presumption of all fevers as ‘malaria’ has often impeded probing for these other conditions .In 2010, WHO revised malaria treatment guidelines to recommend diagnosis of all suspected malaria cases prior to treatment given the increasing availability of malaria rapid diagnostic tests (RDT) . This poMalawi recently adopted the ‘test and treat’ strategy in its National Malaria Strategic Plan and began nationwide RDT deployment in July 2011 . A natioIn this paper, a national facility census conducted in Malawi in 2013–2014 was analyzed to examine integrated paediatric fever management using RDT and IMCI, including other presenting complaints, completed assessments, diagnoses/classifications, and treatment prescriptions . The larMalaria is endemic in most parts of Malawi with peak transmission in November–April, although transmission has declined in recent years. Malawi’s health system is primarily comprised of government-run facilities and publicly supported facilities run by the Christian Health Association of Malawi (CHAM) . This syThe Malawi Service Provision Assessment (SPA) was conducted in June 2013–February 2014 by the Ministry of Health and the Demographic and Health Survey (DHS) programme, which includes facility and laboratory audits, observed consultations, patient exit interviews, and health worker interviews. Survey methods are described elsewhere . BrieflyEthical approval for collection of these data was obtained by the DHS programme from the Department of Health and Human Services Institutional Review Board (IRB) and the host country IRB, which includes authorization to distribute unrestricted survey files for secondary analysis purposes upon receipt of a research proposal. Written informed consent was obtained separately from health workers and caregivers prior to participation in the observation, exit interview and re-examination .Children aged 2 months–5 years attending an observed outpatient consultation as a first-time visit for an illness were included if they had a fever complaint and provided consent for the observed consultation and exit interview Fig. . The antTable Antibiotic over-treatment or any antibiotic prescription ‘without antibiotic need’ is defined as a IMCI-pneumonia negative classification based on re-examination and additionally excluding the following diagnoses recorded during the consultation: sepsis, acute ear infection, mastoiditis, dysentery, abscess, or severe malnutrition. Any antibiotic prescription includes any antibiotic injection (benzyl penicillin or other) or antibiotic capsule, syrup or tablet  that the provider reported was prescribed during the consultation. Table Visual content mapping depicted the potential inter-relationships of input variables on clinical treatment decisions using the Visual Understanding Environment 3.3.0  . FrequenClassification trees were used to learn the relative importance of main predictors (RDT conducted and RDT result) and their inter-relationships with other input variables on the binary outcome of antibiotic over-treatment. A model-based recursive partitioning approach  was usedIn this analysis, a mixed-effects logistic regression model was initially fit to estimate the relationship between the RDT result (or RDT conducted) and antibiotic over-treatment, with observations nested within facility identifiers. The potential influence of 38 other variables on this relationship was learned through recursive partitioning that allowed for detection of sub-group interactions and estimation of random effects parameters . ParametThe Malawi Service Provision Assessment 2013–2014 included 977 facilities out of 1060 on the Ministry of Health master facility list with non-response due to refusal (3 %), closure (2 %), inaccessibility (2 %), or other issue (1 %). A total of 2950 sick child clients met inclusion criteria and 1981 reported fever complaints  also reported cough or difficult breathing (CDB) complaints; 569 (29 %) had diarrhoea complaints; 359 (18 %) reported other complaints including skin problems, eye problems, ear problems, stomach problems, injuries or other issues; 1021 (52 %) reported any danger sign ; 117 (6 %) reported fever alone with no other complaint or danger sign  either spontaneously mentioned the fever complaint or were asked about fever by the provider during the consultation; 1386 (70.0 %) had their temperature taken or body felt for hotness; 1426 (72.0 %) had a malaria RDT done prior to the consultation or were referred for malaria diagnosis; 44 (2.2 %) had neck checked for stiffness; 524 (26.5 %) had palm pallor checked; 185 (9.3 %) had the inside of their mouth checked; and 563 (28.4 %) were undressed for examination (up to shoulders/down to ankles). Among 1436 clients with both fever and CDB complaints, 256 (17.8 %) had respiratory rates counted for 60 s. Among 569 clients with fever and diarrhoea complaints, 98 (17.3 %) had skin turgor checked for dehydration  had malaria RDT conducted prior to the consultation with results reported. Among 312 with reported RDT-positive results, 265 (85.1 %) received first-line anti-malarial prescriptions; 22 (7.0 %) received second-line anti-malarial prescriptions; and 25 (7.9 %) received no anti-malarial prescription . Among 434 with reported RDT-negative results, 44 (10.2 %) received any anti-malarial prescription   were assessed for IMCI pneumonia with results reported. Among 376 with non-severe IMCI-pneumonia from re-examination, 148 (39.4 %) received first-line antibiotic prescriptions; 123 (32.7 %) received second-line antibiotic prescriptions; and 105 (27.9 %) received no antibiotic prescription (antibiotic under-treatment). There were 917 with a negative IMCI-pneumonia classification and a total of 1411 were further categorized as ‘without antibiotic need’. Among 1411 clients ‘without antibiotic need’, 830 (58.8 %) received any antibiotic prescription (antibiotic over-treatment)  were given diagnoses of dehydration or intestinal/digestive issue. Among 260 with these diagnoses, 187 (72.1 %) received oral rehydration solution (ORS) and 148 (56.9 %) received both ORS and zinc prescriptions.Among the sub-set of 526 clients ‘without antibiotic need’ and reported RDT results, RDT-negative clients had 16.8 (95 % CI 8.6–32.7) times higher antibiotic over-treatment odds compared to RDT-positive clients in the crude mixed-effects logistic regression model. CDB complaint was a statistically significant classifier of this relationship learned through recursive partitioning (p < 0.001). Figure Figure Integrated paediatric fever management was sub-optimal in terms of fever assessments completed and poor antibiotic targeting, although findings suggest common compliance to malaria treatment guidelines. The RDT negative result was strongly associated with antibiotic over-treatment conditioned by CDB complaints.In this study, only 6 % of clients with fever complaints had no other complaint or danger sign underscoring the critical need for integrated protocols to manage sick children –3. It waYet general fever assessments were less commonly conducted despite being essential for differential diagnosis. This finding is consistent with other research showing poor IMCI implementation in Malawi and other settings , 29. TheThese findings demonstrate the strong influence of RDT-negative results on antibiotic over-treatment and an inter-relationship with CDB complaints, which reinforces the primary importance of patient symptoms and diagnostic test results on clinical treatment decisions. This is consistent with research showing widespread antibiotic prescriptions for RDT-negative cases –11, and Taken together, these results underscore growing concerns about irrational antibiotic prescription practices in the era of test-based malaria case management , particuTo this end, the IMCI algorithm has been adapted to reflect test-based malaria treatment guidance, and there are efforts to further strengthen these guidelines based on recent etiology studies , 37, andThese results should be viewed in light of data limitations. First, client selection is based on sick child attendance on the interview date and do not represent clients visiting facilities on different dates/seasons, nor all sick children in Malawi. Second, providers may perform better during observations than in routine conditions biasing results towards better practices, including RDT compliance . Third, Measurement limitations for main predictors and the outcome should also be highlighted. First, RDT results are based on provider reports without supporting documentation. The provider reports RDT results after providing information on diagnoses and prescriptions. Some providers may misreport a negative result as positive if anti-malarial medicines were prescribed to seem in compliance with guidelines. Misclassification of the positive result as negative seems less likely in this scenario. This could potentially explain common RDT compliance found in this assessment and these results should be corroborated by additional studies. Second, RDT compliance estimates are only for clients diagnosed by the consultation time and do not include blood smear or RDT results not available by the initial consultation. Facilities conducting RDT prior to the consultation may be systematically different from other facilities in ways that influence compliance, such as larger facilities with more staff and better quality care. Third, antibiotic over-treatment is notoriously difficult to measure in settings without diagnostics to differentiate bacterial from other pathogenic causes. This paper defines ‘need’ according to IMCI antibiotic indications for pneumonia and provider reported diagnostic categories requiring antibiotics: sepsis, dysentery, mastoiditis, acute ear infection, abscess, or severe malnutrition. Urinary tract infection is not a diagnostic category and is not included in this definition. Clients assigned these diagnoses may not have the underlying condition and may not need antibiotics. The ‘without antibiotic need’ definition in this study therefore underestimates true lack of need. Fourth, IMCI pneumonia can be difficult to assess even by a trained provider leading to some misclassification in either direction .Based on 977 facilities and 1981 eligible clients, study findings demonstrate sub-optimal integrated paediatric fever management practices in Malawi health facilities in 2013–2014. While malaria-specific assessments and RDT-guided treatment seemed common, other fever assessments were not often completed and poor antibiotic targeting was demonstrated. RDT-negative results were strongly associated with antibiotic over-treatment conditioned by CDB complaints. These results suggest moving beyond malaria-focused ‘test and treat’ strategies toward ‘IMCI with testing’ to improve quality fever care and rational use of both anti-malarial and antibiotic medicines. Integrated paediatric fever management using RDT and IMCI together is critical to improve antibiotic targeting in line with recent commitments to combat antibiotic resistance, and should be considered for inclusion in national action plans developed by malaria-endemic African countries in the next year.


The transduction of sound into electrical signals occurs at the hair bundles atop sensory hair cells in the cochlea, by means of mechanosensitive ion channels, the mechano‐electrical transducer (MET) channels.The MET currents decline during steady stimuli; this is termed adaptation and ensures they always work within the most sensitive part of their operating range, responding best to rapidly changing (sound) stimuli.Snell's waltzer) for hereditary deafness in humans that has a mutation in the gene encoding an unconventional myosin, myosin VI, which is present in the hair bundles.In this study we used a mouse model  minus end‐directed unconventional myosin, myosin VI, cause hereditary deafness in mice  and humans. In the sensory hair cells of the cochlea, myosin VI is expressed in the cell bodies and along the stereocilia that project from the cells’ apical surface. It is required for maintaining the structural integrity of the mechanosensitive hair bundles formed by the stereocilia. In this study we investigate whether myosin VI contributes to mechano‐electrical transduction. We report that Ca2+‐dependent adaptation of the mechano‐electrical transducer (MET) current, which serves to keep the transduction apparatus operating within its most sensitive range, is absent in outer and inner hair cells from homozygous Snell's waltzer mutant mice, which fail to express myosin VI. The operating range of the MET channels is also abnormal in the mutants, resulting in the absence of a resting MET current. We found that cadherin 23, a component of the hair bundle's transient lateral links, fails to be downregulated along the length of the stereocilia in maturing Myo6 mutant mice. MET currents of heterozygous littermates appear normal. We propose that myosin VI, by removing key molecules from developing hair bundles, is required for the development of the MET apparatus and its Ca2+‐dependent adaptation.Mutations in  The transduction of sound into electrical signals occurs at the hair bundles atop sensory hair cells in the cochlea, by means of mechanosensitive ion channels, the mechano‐electrical transducer (MET) channels.The MET currents decline during steady stimuli; this is termed adaptation and ensures they always work within the most sensitive part of their operating range, responding best to rapidly changing (sound) stimuli.Snell's waltzer) for hereditary deafness in humans that has a mutation in the gene encoding an unconventional myosin, myosin VI, which is present in the hair bundles.In this study we used a mouse model (We found that in the absence of myosin VI the MET current fails to acquire its characteristic adaptation as the hair bundles develop.We propose that myosin VI supports the acquisition of adaptation by removing key molecules from the hair bundle that serve a temporary, developmental role. IHCinner hair cellMETmechano‐electrical transducerOHCouter hair cellMyo6 was one of the first deafness genes identified  become disorganized, with a partial loss of their normal orientation and a tendency of individual stereocilia to fuse  mutant mouse to identify a crucial role for myosin VI in the functional development of the hair bundle's mechano‐electrical transducer (MET) apparatus during a time when the MET currents are undergoing major biophysical changes  Act 1986 and was approved by the University of Sussex, University of Sheffield and Wellcome Trust Sanger Institute Ethical Review Committees.Snell's waltzer (sv) mutant mice, which have an intragenic deletion in the motor domain of the myosin VI gene : 135 NaCl, 5.8 KCl, 1.3 CaCl2, 0.9 MgCl2, 0.7 NaH2PO4, 2 Na‐pyruvate, 5.6 d‐glucose, 10 Hepes‐NaOH. Amino acids and vitamins for Eagle's minimum essential medium (MEM) were added from concentrates . The pH was adjusted to 7.5 and the osmolality was about 308 mosmol kg−1. The organs of Corti were observed with upright microscopes  with Nomarski optics.The organs of Corti were dissected and transferred to a microscope chamber and immobilized using a nylon mesh fixed to a stainless steel ring. The chamber was perfused at a flow rate of about 10 ml hm): 147 CsCl, 2.5 MgCl2, 1 EGTA‐NaOH, 2.5 Na2ATP, 5 Hepes‐CsOH ; 106 l‐glutamic acid, 20 CsCl, 10 Na2phosphocreatine, 3 MgCl2, 1 EGTA‐CsOH, 5 Na2ATP, 5 Hepes‐CsOH and 0.3 GTP . The intracellular solution used for recording K+ currents contained: 145 mm KCl, 3 mm MgCl2, 1 mm EGTA‐KOH, 5 mm Na2ATP, 5 mm Hepes‐KOH . Data were acquired using either Asyst  or pClamp  software, filtered at 2.5 or 5 kHz, sampled between 5 and 50 kHz and stored on computer for off‐line analysis. Basolateral membrane currents were corrected off‐line for linear leak conductance and voltage drop across the residual series resistance after compensation. For MET current recordings, no correction was made for the drop across the residual series resistance , which was at most 4 mV at extreme potentials. In all recordings, membrane potentials were corrected for liquid junction potentials of either −4 mV (CsCl‐based intracellular solution) or −11 mV (l‐glutamic acid‐based intracellular solution) measured between pipette and bath solutions.Hair cells from the apical coil of the cochlea (91 OHCs and 7 IHCs) were whole‐cell voltage clamped to record MET or basolateral membrane currents at room temperature (21–25°C) using an EPC‐7, EPC‐8  or an Optopatch patch clamp amplifier . Patch pipettes (resistance in the bath 2–3 MΩ) were pulled from soda glass capillaries  and coated with surf wax . MET currents were recorded with one of the two following intracellular solutions containing  IHCs because of their particularly disorganized bundle morphology, so for IHC MET current recordings we only quote driving force from the fluid jet rather than bundle displacement. Hair bundle stiffness  was calculated from the linear fluid velocity of the jet  and by modelling the hair bundles as prolate spheroids, as previously described in detail : 147 NaCl, 5.8 KCl, 0.1 CaCl2, 0.7 NaH2PO4, 2 Na‐pyruvate, 5.6 d‐glucose and 10 Hepes‐NaOH ; that with 10 mm Ca2+ was (in mm): 132 NaCl, 5.8 KCl, 10 CaCl2, 0.7 NaH2PO4, 2 Na‐pyruvate, 5.6 d‐glucose and 10 Hepes‐NaOH . The solutions were superfused via a pipette with a much larger tip diameter than that of the fluid jet, positioned orthogonally to the axis of mechanical sensitivity of the hair bundle, and the flow did not directly stimulate the stereocilia. For every extracellular solution change, the fluid jet used for stimulating the hair bundles was filled with the new solution by suction through its tip to prevent dilution of the drug concentration. The effects of the Ca2+ chelator BAPTA  on the MET current were tested by using two different intracellular concentrations (0.1 and 10 mm Na4BAPTA), instead of 1 mm EGTA‐CsOH, in the l‐glutamic acid‐based intracellular solution and osmolality was kept constant by adjusting the concentration of the l‐glutamic acid.To test the effects of extracellular Ca mm Fig.  instead m FM1‐43 (N‐(3‐triethylammoniumpropyl)‐4‐(4‐(dibutylamino)styryl) pyridiniumdibromide, Molecular Probes) were prepared in water. FM1‐43 dye labelling was studied using bath application. After dissection, organs of Corti (aged P3–P6) were held in position at the bottom of a chamber under a nylon mesh and perfused with normal extracellular solution. All experiments were performed at room temperature (22–25°C), as previously described  using a 63× water immersion objective. Images were captured from live cultures at fixed time points after dye application using a 12‐bit cooled CCD camera . For each experiment cochleae from +/sv and sv/sv mutant mice were dissected and processed simultaneously in the same chamber to reduce variability between different experiments. A total number of 12 +/sv and 12 sv/sv cochleae from eight mice of each genotype were used.Stock solutions of 3 mm BAPTA for 15 min to expose CDH23 ectodomain epitopes and then fixed in 3.7% formaldehyde in 0.1 m sodium phosphate buffer for 1 h at room temperature and washed three times in PBS. Cochlear coils were pre‐blocked and permeabilized in TBS containing 10% heat‐inactivated horse serum and 0.1% TX‐100 for 1 h, and incubated overnight in the same solution containing a 1:100 dilution of the rabbit antibody Ela3N (kindly provided by Prof. C. Petit) that is directed against peptide epitopes in the ectodomain of CDH23 ; six homozygous 6JMyo7a .For cadherin 23 (CDH23) labelling, dissected cochleae were treated with 5 mm sodium cacodylate buffer (pH 7.4) and then fixed for 3 h at room temperature in the same fixative. Samples were then carefully washed in PBS and processed with the OTOTO method adapted from Hunter‐Duvar  affected MET current size we used two‐way ANOVA with Bonferroni post hoc tests. P < 0.05 was used as the criterion for statistical significance.Averaged data are presented as mean ± SEM and statistical comparisons are based on the paired or unpaired two‐tailed Student's Snell's waltzer mice, concentrating on OHCs because IHCs are more difficult to approach for hair bundle stimulation and patch clamp recording during the first postnatal week. In +/sv OHCs bundle movement towards the kinocilium  that, for intermediate‐sized MET currents, declined with two time constants : a fast one of 0.34 ± 0.04 ms  and a residual slow one of 12 ± 3 ms . This decline is due to adaptation  for small excitatory stimuli. Inhibitory hair bundle stimulation  was observed. The time course of relaxation following the rebound adaptation proceeded with a fast  and a slow time constant (8 ± 2 ms). At +86 mV  adaptation was abolished , as previously observed for hair cells from wild‐type mice . This is consistent with Ca2+ entry, via the resting MET current at −84 mV, inducing a degree of adaptation, and thus closing some MET channels and inducing a rightward shift and a change in shape of the curve describing the relationship between MET current and bundle displacement  from various wild‐type mouse strains , with a reversal potential of +3.8 ± 0.2 mV (n = 15), again in the range of values reported for wild‐type mouse OHCs  or depolarized  membrane potentials, currents were not usually detected at rest and could not be elicited for excitatory bundle movements smaller than 60 ± 15 nm . There were no signs of an adaptive decline during excitatory force steps  or of a rebound at the end of inhibitory force steps . From about P5 some sv/sv OHCs responded to large negative bundle displacements with an inward current  of −34 ± 7 pA  instead of the normal reduction in the (inward) resting MET current. This MET current with opposite polarity was different from the anomalous MET current recently reported  and not significantly different from +/sv controls. The relationship between MET current size and bundle displacement, both measured just after the onset of activation, is shown in Fig. E. In sv/sv OHCs, the operating range of the current–displacement relationship  for positive force steps is shifted to the right compared to that of the littermate +/sv controls . The resting open probability did not increase upon depolarization in the homozygous mutants and there was no leftward shift or shape change of the current–voltage curves, pointing to a complete absence of Ca2+‐induced adaptation. The only difference between the fitted Boltzmann curves , when the hair bundles were less disorganized and larger MET currents (up to −660 pA at −84 mV) could still be recorded, showing that the drastic increase in hair bundle deterioration from about P6 onwards is not the cause of the absence of MET current adaptation. The current–displacement relationship  was well fitted with the same absolute parameter values for positive and negative displacements, except the size of the currents, which was 35% smaller for negative displacements. The fact that we could fit identically shaped current–displacement relationships for positive and negative bundle displacements suggests that, as the hair bundles become progressively more disorganized during postnatal development, some tip links lose their normal orientation. This is likely to be a direct consequence of some stereocilia being misaligned away from the normal direction of bundle sensitivity, which is a feature of sv/sv OHCs from about P3 onwards , sodium (INa) and calcium (ICa) currents were otherwise similar to those of +/sv OHCs . Fluid force in the opposite direction closed the small fraction of the MET channels that were open when the bundle was in its resting position. When MET currents were elicited during depolarizing voltage steps to +99 mV the adaptive decline was no longer present and the currents instead showed a slow further increase following the initial rapid response . Inhibitory force stimuli showed that the current activated at rest was considerably increased compared to that at −81 mV, resulting in a leftward shift and change in the shape of the relationship between MET current and driver voltage to the fluid jet . Expressed as a fraction of the maximum, saturating MET current, the resting current increased from 3.4 ± 0.9% at −81 mV to 20 ± 3% at +99 mV (n = 3 IHCs). The maximum saturating MET current was −515 ± 90 pA at −81 mV and 912 ± 161 pA at +99 mV (n = 3). Although fewer data from early postnatal wild‐type mouse IHCs are available for comparison than there are for OHCs . The currents were also about half the size of those of the +/sv IHCs, with maximum currents reaching −288 ± 35 pA at −81 mV and 457 ± 52 pA at +99 mV (n = 4) , suggesting the loss of some MET channels, while the slow onset of the currents seen in some cases points to less efficient gating of the remaining MET channels. As observed for the OHCs , inhibitory force steps elicited small MET currents with a similar activation range to those seen in response to excitatory force steps . The relationship between MET current and driver voltage was essentially unchanged upon depolarization . Basolateral currents of the sv/sv IHCs are likely to be normal during the first postnatal week, but fail to mature . Despite the disorganized hair bundles, sv/sv OHCs had tip links, just like those of +/sv controls , in keeping with the features of their MET currents being distinct from those of the anomalous MET currents observed in the absence of tip links  suggested that in sv/sv OHCs the MET channel might be insensitive to Ca2+ modulation. To test this hypothesis directly, MET currents were recorded in both +/sv and sv/sv OHCs during superfusion of different concentrations of extracellular Ca2+  but this was not seen in sv/sv OHCs , again indicative of a lack of Ca2+‐dependent adaptation. The MET currents of the mutant cell of Fig. B did not saturate, hence their ‘pointy’ appearance, but they were not like the anomalous MET currents  and eight sv/sv (P5–P7) OHCs.The absence of the leftward shift of the current–displacement curve at depolarized potentials Fig. E suggesa2+ Fig. . MET cura2+ Fig. A but thHCs Fig. B, again2+‐dependent adaptation of the MET current in sv/sv hair cells was modulated by free intracellular Ca2+ in the stereociliary bundle. To this end we changed the cell's Ca2+ buffering capacity using different concentrations of the fast Ca2+ buffer BAPTA in the intracellular solution and recorded MET currents in response to force steps  and in the presence of a low BAPTA concentration (0.1 mm), MET currents recorded at −81 mV can be seen to adapt during non‐saturating bundle displacements . Upon stepping the membrane potential to +99 mV, time‐dependent adaptation was no longer present and the resting MET current increased , as also observed in the presence of 1 mm EGTA as the intracellular Ca2+ buffer . By contrast, all forms of Ca2+‐dependent adaptation were absent in sv/sv OHCs irrespective of membrane potential or BAPTA concentration . Membrane depolarization or increasing the intracellular BAPTA concentration from 0.1 to 10 mm produced a leftward shift in the relationship between MET current and bundle displacement in heterozygous control  but not in sv/sv OHCs .We further tested whether Caeps Fig. . In heteration 0. mm, MET HCs Fig. B. By coion Fig. C and D.HCs Fig. F.The above findings show that myosin VI is required for the acquisition of MET channel adaptation. Considering that one proposed role for myosin VI is to traffic molecules toward the minus ends of actin filaments . By contrast, the hair bundles of sv/sv mutant mice remained strongly immunoreactive for CDH23 throughout the immature stages studied, up to P6 . The hair bundles of mutant OHCs from the same apical region of the cochlea exhibited a significantly greater apparent overall steady‐state bundle stiffness  compared to littermate controls , possibly due to the persistence of the lateral links and fusion of stereocilia starting from their bases.CDH23 is a member of the cadherin superfamily of cell–cell adhesion molecules that has been proposed to form, in addition to the upper ends of tip links  showed a developmental pattern for CDH23 immunoreactivity similar to that of control cells , indicating that the persistence of CDH23 was specific to the absence of myosin VI and not due to general hair bundle deterioration.To determine whether this failure to clear CDH23 from the hair bundle during early postnatal development was a specific feature of the sv or sv/sv hair cells, as reported during normal development  that retain CDH23 . The progressively deteriorating bundle morphology  was correlated with a progressive decline in MET current size . The current size of heterozygous control and mutant OHCs was significantly different . Bonferroni post hoc tests showed that there was no difference at P2 but at P4, P6 and P7 currents in sv/sv OHCs were significantly smaller (P < 0.0001).At P2, when hair bundles express high levels of CDH23, MET current adaptation was not observed in either +/nts Fig. D and E H23 Fig. B. The pogy Fig. B was coize Fig. F. The cSnell's waltzer mutant OHCs and IHCs showed altered hair bundle morphology, an absence of resting MET current and a lack of Ca2+‐dependent adaptation. The postnatal decline in CDH23 immunoreactivity, which normally takes place concomitant with the loss of transient lateral links from the immature stereocilia, fails to occur in the Snell's waltzer mutants. Thus, our results identify myosin VI as a protein required for the normal maturation of the MET complex. The heterozygous +/sv hair cells, by contrast, had apparently normal MET current properties, including adaptation, size and reversal potential, like those reported in cochlear hair cells from wild‐type mice studied under similar conditions in response to stimulation by force from a fluid jet  are functional. The significantly smaller MET currents in the mutants compared to those of controls are likely to be related to a progressive reduction in the number of functional stereocilia that have not yet fused  and the lack of a leftward shift in the current–displacement relationship upon depolarization to near the Ca2+ equilibrium potential , dynamic and steady‐state manifestations of Ca2+‐dependent adaptation, respectively  or strong intracellular Ca2+ buffering with BAPTA, but different from the findings with the sv/sv hair cells, this results in a large fraction of the MET current being activated at rest in wild‐type cochlear hair cells , forms the tip links connecting neighbouring stereocilia  and to G.P.R. and C.J.K. (MR/K005561/1). W.M. was supported by the Wellcome Trust (102892). K.B.A. was supported by the NIH  and the I‐CORE Program of the Planning and Budgeting Committee and The Israel Science Foundation (grant no. 41/11). G.P.R. was supported by the Wellcome Trust (087377). K.P.S. was supported by the Wellcome Trust (098051 and 100669).Snell's waltzer mice are deaf and have balance problems due to a recessive mutation in the gene encoding an unconventional myosin, myosin VI, found in sensory hair cells. Human mutations in this gene cause recessive deafness from birth (DFNB37) and dominant progressive hearing loss starting in childhood (DFNA22). We report that auditory hair cells of Snell's waltzer mice are abnormal in the way their mechanosensitive currents adapt to a steady input, optimizing the cells' sensitivity to rapidly changing stimuli. This adaptation normally develops well before hearing onset. This does not happen in the two types of hair cells, inner and outer, of the Snell's waltzer mutants. We propose that this occurs because myosin VI removes hair bundle components such as transient lateral links that serve a temporary, developmental role, down the bundle. Simultaneously with the acquisition of adaptation, the mechanosensitive current becomes partially activated even when the hair bundles are not stimulated. This also fails to occur in the mutants. As a knock‐on effect, the resting potential would hyperpolarize slightly, leading to a previously reported failure of inner hair cell maturation. This narrows the therapeutic window of potential future efforts to develop gene therapy to replace the missing myosin VI in DFNB37, which would need to be applied in utero to rescue normal hair cell development and prevent the hair‐cell degeneration that follows developmental failure. For DFNA22, therapy might be feasible after birth with timely genetic diagnosis, for example if the dominant allele could be inactivated using gene editing.


Freezing-thawing resistance is a very significant characteristic for concrete in severe environment (such as cold region with the lowest temperature below 0°C). In this study, ordinary-air-entrained (O-A-E) concrete was produced in a laboratory environment; the compressive strength, cubic compressive strength of C50, C40, C30, C25, and C20 ordinary-air-entrained concrete, tensile strength, and cleavage strength of C30 ordinary-air-entrained concrete were measured after fast freeze-thaw cycles. The effects of fast freeze-thaw cycles on the mechanical properties (compressive strength and cleavage strength) of ordinary-air-entrained concrete materials are investigated on the basis of the experimental results. And the concise mathematical formula between mechanical behavior and number of fast freeze-thaw cycles was established. The experiment results can be used as a reference in design, maintenance, and life prediction of ordinary-air-entrained concrete structure  in cold regions. Durability of concrete –4 is theThe effects of action of freeze/thaw cycles on air-entrained concrete and plain concrete are well documented and many researchers have documented the improvement on the freeze/thaw resistance of air-entrained concrete over plain concrete –19. RefeMany current research works were found to deal with the durability of concrete, especially the freeze-thaw resistance in cold environment , 18, 19.# and 42.5# (GB175-2007) [# and 42.5#, Portland cement was 32.5 and 42.5 MPa at 28 days), (2) natural river sand (fineness modulus was 2.6), and (3) coarse aggregate (crushed stone with diameter 5 mm~10 mm) were used. In this study, local materials (1) Portland cement 32.575-2007)  (the staThe concrete samples used for cubic compressive strength tests were cube with dimensions: 100 mm × 100 mm × 100 mm. The concrete samples used for compressive strength tests were prismoid with dimensions: 100 mm × 100 mm × 200 mm (got through severing the prismoid specimen from middle). Steel molds were used to cast the concrete samples. All concrete samples were demoulded at 24 h after casting. Thereafter, all the samples were cured in the condition with 20 ± 3°C and at 95% RH for 23 days. Then the samples were stored in water (the time in water was 4 days) until the test of fast freezing and thawing cycles.In this study, the freeze-thaw test machine  meeting The deterioration of surface of O-A-C concrete samples undergoing fast freeze-thaw cycles is shown in The tensile strain in the direction perpendicular to free surface will be caused due to compression load or cleavage load. And the crack(s) will be generated when the tensile strain exceeds the ultimate tensile strain. It was noticed that direction of the crack(s) is random due to the impact of the uneven distribution of coarse aggregates. The failure process of the O-A-C concrete samples under the action of cleavage and tension load was instantaneous and was always caused by a single crack at the center of the sample.For the concrete structures in cold region, the deterioration of concrete material was mainly caused by internal crack growth due to fast freeze-thaw cycles. The loss of strength will be caused during fast freeze-thaw cycles. So the mechanical properties of ordinary-air-entrained concrete after fast freeze-thaw cycles were measured.2); at least three sample tests were carried out for each test group. Tables The compressive stress was got through dividing the applied load by loading-carrying area 0.01 m; at leasThe relationship of the cubic compressive strength versus number of fast freeze-thaw cycles and compressive strength versus number of fast freeze-thaw cycles is shown in Figures Reference , 25 invefts denotes the cleavage strength, F is the failure load, and A is the area under cleavage load.The cleavage strength can be drawn through  as folloAs seen from fcuD(fcD) is the value of cubic compressive strength (compressive strength) of O-A-C concrete after fast freeze-thaw cycles; N is the number of fast freeze-thaw cycles; α1,  α2, and α3  are the regress parameters for the relationship between cubic compressive strength and number of fast freeze-thaw cycles; β1, β2, and β3 are the regress parameters for the relationship between compressive strength and number of fast freeze-thaw cycles.The relationship between the cubic compressive strength (compressive strength) and numbers of fast freeze-thaw cycles was analyzed through the least square regression method; the mathematic expression of exponential function is given out asα1, α2, α3, β1, β2, and β3 was given in The value ofregress parameters For the cubic compressive strength and compressive strength of O-A-E concrete after the action of fast freeze-thaw cycles, a comparison of the experimental results with calculated results obtained from  is illusIt can be concluded that there was no great difference in the strength loss of O-A-E concrete under uniaxial tension and compression due to fast freeze-thaw cycles. But the reduction of compressive strength can be associated with the initiation and propagation of crack parallel to the direction of tensile load due to the action of fast freeze-thaw cycles. However, the reduction of tensile strength should be associated with the initiation and propagation of crack perpendicular to the direction of tensile load.For O-A-E concrete under the action of tensile load, the initiation and growth of inherent microcracks leaded to the decrease of carrying area, and then the stress concentration at critical crack tips will be caused and at last resulted in the cracks to propagate further. So damage even failure of the concrete occurs after the initiation and growth of crack caused by fast freeze-thaw cycles.The durability of O-A-E concrete was improved through reducing stresses caused by freezing water in pores. The volume expansion when water converts from liquid to solid under the action of “freezing.” The relief for this pressure can be obtained when entrained air was introduced into concrete which can provide space for free water to flow into. But if there were no air voids, the stress will be caused by pressure on the concrete and the stress can create cracks which cumulatively begin to cause disruption of the concrete.Plain concrete also contains entrapped air that exists with larger bubbles. Compared with bubble state in O-A-E concrete, the larger bubbles in plain concrete are typically less evenly distributed. And these larger bubbles cannot effectively reduce stress caused by the action of “freezing.” Through comparing the test results in this paper with the conclusion got by other authors , 24, theThe mechanical property  of C30 O-A-E concrete decreased as the fast freeze-thaw cycles were repeated; the strength loss of C30 O-A-E concrete under compression and tension under the action of fast freeze-thaw cycles is evident. After the same cycles of fast freeze-thaw, the decreased percentage of cubic compressive strength and compressive strength is larger for C20 O-A-E concrete specimens than for C25, C30, C40, and C50 O-A-E concrete specimens.The main reason that induced cracks in concrete is the volume expansion caused by water frozen into ice. The second reason that induced cracks is the thermal stress developed under the action of repeated freeze-thaw.The durability of concrete can be improved greatly by adding air-entraining agent into concrete.The freeze-thaw durability of concrete should be taken into consideration in structure design and maintenance.Based on the experimental work in this paper and the discussion about the test results, the following conclusions can be drawn.


To assess the antibiotic prescribing practices of doctors working in the Lao People's Democratic Republic and their knowledge of local antibiotic resistance patterns.Doctors attending morning meetings in 25 public hospitals in four provinces were asked to complete a knowledge, attitude and practice survey. The questionnaire contained 43 multiple choice questions that the doctor answered at the time of the meeting.Staphylococcus aureus. Most participants had no information about local antibiotic resistance for Salmonella Typhi  and hospital-acquired pneumonia . Unnecessary antibiotic prescriptions were considered as harmless by 115 participants and 148 considered locally-available generic antibiotics to be of poor quality. Nearly three-quarters (280/386) of participants agreed that it was difficult to select the correct antibiotics. Most participants (373/386) welcomed educational programmes on antibiotic prescribing and 65.0% (249/383) preferred local over international antibiotic guidelines.The response rate was 83.4% (386/463). Two hundred and seventy doctors (59.8%) declared that they had insufficient information about antibiotics. Only 14.0% (54/386) recognized the possibility of cephalosporin cross-resistance in methicillin-resistant Doctors in the Lao People's Democratic Republic seem to favour antibiotic prescribing interventions. Health authorities should consider a capacity building programme that incorporates antibiotic prescribing and hospital infection control. We selected four of 17 provinces – Khammuane, Luangprabang, Sekong and Vientiane capital – that represent the national range of population density, prevalence of poverty  comprised 43 multiple choice questions related to prescription of antibiotics. They were grouped into seven topics. The first six topics addressed attitudes and practices: (i) demographic and professional profile; (ii) awareness of antibiotic resistance; (iii) sources of information and continuing education on antibiotics; (iv) professional confidence and inputs sought when prescribing antibiotics; (v) factors influencing decisions about antibiotic prescribing; and (vi) the acceptability and appropriateness of potential interventions. For these six topics, answers were presented in a 6-point Likert’s scale, ranging from “strongly agree” to “strongly disagree”, from “very useful” to “not familiar with” or from “always” to “never”. The seventh topic assessed basic knowledge – i.e. spectrum of antibiotics, cross-resistance, pharmacologic properties – as well as case-based questions – i.e. choice, dosage and duration of antibiotic treatment, antibiotic treatment for watery diarrhoea and upper respiratory tract infection, dose adjustments in case of renal failure and safety during pregnancy. Two questions of national relevance – one on melioidosis and one on typhoid fever – were added to the seventh topic. The questionnaire also included two questions assessing knowledge of local antibiotic resistance: the resistance rate of To prevent repetitive or socially desirable answers, we randomly ordered the first six topics. The knowledge questions were placed in the end of the questionnaire to avoid influencing the answers for the attitude and practice questions.The study was reviewed and approved by the Lao Ministry of Health´s ethics committee on 27 February 2012. Written informed consent was deemed not to be necessary, since the study only assessed knowledge, attitude and practice of the participants and data were collected anonymously.Data were entered by surveyors in a Microsoft Access database created specifically for the study . Questionnaires with missing data were included in the analysis.2χ tests or Fisher’s exact tests when appropriate. The results of the antibiotic knowledge questions  were expressed by the values 0 (not correct) or 1 (correct) and a score was calculated for a maximum of 10 points. Continuous variables were expressed by means and standard deviations (SD) and assessed for statistical significance using either Student’s test, the unpaired Wilcoxon’s test or the one-way ANOVA test. Statistical analyses were performed using the software STATA SE 11.1  and 95% confidence interval was calculated. A two-sided P-value of ≤ 0.05 was considered as significant.The six Likert’s items were combined into two categories: “strongly agree/agree”, “very useful/useful” and “always/most of the time” versus the remaining options of the scale unless otherwise stated. Categorical variables were expressed by proportions and their significance was assessed by The professional and demographic characteristics of participants are presented in P = 0.001) agreed so for their own practice. There were significant differences between the four provinces in perception of overuse of antibiotics in the community. Whereas 82.8% (216/261) and 76.5% (13/17) of the doctors in Vientiane capital and Sekong, respectively, thought antibiotics were overused, only 61.4% (35/57) in Luangprabang and 56.9% (29/51) in Khammuane agreed  agreed that antibiotic resistance is a problem. However, more doctors agreed that the problem was greater globally (323/386) than nationally (288/383) and even fewer doctors saw it as a problem at their hospital (251/385) or in their practice (254/385). Seventy-six percent (293/386) of the participants thought that antibiotics are overused in hospitals as well as in the community setting, however only 47.1%  declared not having enough sources of information on antibiotic prescribing and 35.2% (136/386) had not attended any training on antibiotic prescribing during the previous year. Doctors obtained information from national guidelines , advice from peers , older colleagues , pharmaceutical companies  and the Internet . The use of Internet was more frequently reported by participants with fewer years of professional experience, for example 95.8% (46/48) of the doctors with two years of experience reported using the Internet, while 66.2% (139/210) of the doctors with more than seven years of experience used this source. Furthermore, the Internet was more used in the province of Vientiane capital  than other provinces  of the participants reported that they felt very confident about their prescription of antibiotics, with most of the remaining participants  replying that they were somewhat confident. However, 72.5% (280/386) agreed that it was difficult to prescribe the correct antibiotics .P = 0.013; About half the participants agreed that patients’ demands contribute to antibiotic prescribing; 49.0% (189/386) and 50.5% (195/386) of participants agreed with this statement for the community and hospital setting, respectively. Eighty-six of the 386 participants (22.3%) declared that antibiotic prescription was more driven by the availability of antibiotics than by the presumed cause of infection and 37.7% (145/385) stated inadequate information about antibiotic availability in their hospital. Review of prescriptions by a senior colleague was reported to occur less than half the time by 65.3% (252/386) of the respondents. Nearly one third  agreed with the statement that unnecessary prescriptions of antibiotics do no harm, this was more frequent among participants in paediatrics  as compared to other departments (One hundred and forty-eight of the 386 participants (38.3%) agreed with the statement that some antibiotics available in their hospital are of poor quality . Most doLocal antibiotic guidelines were preferred over international guidelines for 65.0% (249/383) of participants and 22.0% (85/386) of participants considered local antibiotic guidelines as an obstacle rather than a help. One hundred and seventy-four of 385 doctors (45.2%) thought that restriction of antibiotics was an effective measure to contain antibiotic resistance. Most doctors  welcomed educational programmes on antibiotic prescribing.The mean score for the knowledge questionnaires was 5.9 . There were no differences in results of the knowledge scores between participants’ provinces, positions in the medical hierarchy, years of experience, frequencies in prescribing, departments or types of referral level.Staphylococcus aureus (MRSA) was co-resistant to all three generations of cephalosporins. Only 25.9% (100/386) replied correctly to the question about reducing the dose of gentamicin in case of renal failure. The case-based questions about treatment of melioidosis and typhoid fever were correctly answered by 75.4% (291/386) and 78.2% (302/386), respectively. For the question about diarrhoea without fever, 81.6% (315/386) of participants correctly replied that no antibiotic treatment was indicated. In the case of upper respiratory tract infection (rhinitis with sore throat), 53.4% (206/386) reported that they would prescribe erythromycin.Most doctors had no information about local antibiotic resistance patterns for the pathogens causing typhoid fever and hospital-acquired pneumonia; 54.8% (211/385) and 65.9% (253/384), respectively. Of those who were able to give an estimate of the patterns, the replies were equally distributed among the different proportion categories . For both conditions, most participants reported that they based their estimates on clinical experience.This survey of antibiotic prescribing practices of 386 doctors practicing in four provinces of the Lao People's Democratic Republic, has, like all such surveys, limitations. The multiple-choice format of the questionnaire may have contributed to a social-desirability bias. Not all doctors employed by the hospitals were present at the morning meetings. We focused on hospital doctors and did not assess antibiotic prescribing in the community. Although surveys can provide a snapshot of the situation, additional qualitative research is needed for a more comprehensive understanding of perceptions and practices in antibiotic prescribing.The strengths of this survey include the balanced selection of provinces, the high coverage of hospitals and doctors from all medical levels, and the high response rate. In addition, the survey included all topics – except for economic incentives and workload issues – cited by the World Health Organization as influencing antibiotic prescribing.,As noted elsewhere,,As previously recorded in the Democratic Republic of the Congo and Peru,Patient pressure was recognized as a factor influencing antibiotic prescribing. However, our study showed this to be less of a factor than reported from the community setting in PeruOf particular concern is the high proportion of participants who thought that unnecessary antibiotic prescriptions are harmless for patients; this belief may be driven by fear of treatment failure and lack of laboratory diagnostics.,Two-fifths of the doctors in our study considered that generics were low quality. This perception could be conditioned by reports of sub-standard and counterfeit antimicrobials in the south-east Asian market.Nearly all participants welcomed educational programmes on antibiotic prescribing and two-thirds of participants preferred local antibiotic guidelines. Since local committees to regulate the prescription and use of antibiotics within hospitals are not functional in the Lao People's Democratic Republic, we did not explore if such committees would be acceptable to doctors. However, antibiotic restrictions were perceived as less efficacious in decreasing the use of antibiotics.Salmonella Typhi.Participants had higher knowledge scores on the use of antibiotics in life-threatening conditions – such as melioidosis, typhoid fever and meningitis. However, less than half of the participants knew how to correctly manage upper respiratory tract infections. Theoretical knowledge – such as antibiotic spectrum and dose reduction in renal failure – was meagre. Only a minority knew that MRSA is also resistant to cephalosporins. This may partly be explained by the current rarity of MRSA in the Lao People's Democratic Republic.–For clear and unbiased surveillance of antibiotic resistance, prospective clinical sampling with well-defined criteria should be implemented nationwide. Such operational studies should be subsidized by the government and integrated with a capacity-building programme that includes antibiotic prescribing and hospital infection control.This study identifies action points for improving knowledge and practices of antibiotic prescribers in the Lao People's Democratic Republic. Health authorities should facilitate antibiotic surveillance and provide evidence-based information about local antibiotic resistance and locally-available antibiotics. Introducing a system of quality assurance would reinforce confidence in generic products. Doctors in the Lao People's Democratic Republic appear ready to welcome interventions to improve antibiotic prescribing.


Increasing antimicrobial resistance has necessitated an approach to guide the use of antibiotics. The necessity to guide antimicrobial use via stewardship has never been more urgent. The decline in anti-infective innovation and the failure of currently available antimicrobials to treat some serious infections forces clinicians to change those behaviors that drive antimicrobial resistance. The majority of antimicrobial stewardship (AMS) programs function in acute-care hospitals, however, hospitals are only one setting where antibiotics are prescribed. Antimicrobial use is also high in residential aged care facilities and in the community. Prescribing in aged care is influenced by the fact that elderly residents have lowered immunity, are susceptible to infection and are frequently colonized with multi-resistant organisms. While in the community, prescribers are faced with public misconceptions about the effectiveness of antibiotics for many upper respiratory tract illnesses. AMS programs in all of these locations must be sustainable over a long period of time in order to be effective. A future with effective antimicrobials to treat bacterial infection will depend on AMS covering all of these bases. This review discusses AMS in acute care hospitals, aged care and the community and emphasizes that AMS is critical to patient safety and relies on government, clinician and community engagement. Antibiotic resistance is an important public health concern , which iAntibiotic development has been dwindling since the 1990s. Compared with 1983 to 1987 when 16 new antimicrobials were developed, this number has steadily declined to a mere two new antimicrobials developed from 2008–2012 .According to the Infectious Diseases Society of America (IDSA), antimicrobial stewardship (AMS) includes not only limiting inappropriate use but also optimizing antimicrobial selection, dosing, route and duration of therapy to maximize clinical cure or prevention of infection while limiting unintended consequences, such as the emergence of resistance. The ultimate goal of antimicrobial stewardship is to improve patient care and health care outcomes . AMS canHospital-based AMS programs are based on education coupled with either a “front-end” (or primary) restriction of antimicrobial availability or a “back-end” (or retrospective) review of broad-spectrum empirical therapy with advice regarding streamlining or discontinuing therapy, on the basis of culture and susceptibility testing results and clinical response ,9. HospiThere are several other partners that are critical in hospital-based AMS programs. Medical Microbiologists and the microbiology laboratory have an important and often leading role to play in AMS both inside and outside of working hours ,11. The In hospital-based AMS programs that utilize more primary antimicrobial restriction to antibiotic availability, restrictions are placed on the availability of certain antimicrobial agents. Examples of such restrictions include the need for preapproval before the administration of restricted agents, and the use of special antimicrobial request or prescribing forms. Such programs, when properly implemented can result in large reductions in the overall use of some antimicrobials, but they are also time-consuming, labor intensive, require clinician buy-in and rely on experienced infectious diseases clinicians for their effectiveness ,17.The labor intensity of hospital-based AMS coupled with the rapid turnover of junior medical staff in many teaching hospitals create further challenges to both clinician engagement and AMS program sustainability in the longer-term. Furthermore, it may be that the prescribing practices of junior medical staff are not primarily influenced by guidelines. It has been demonstrated that the influences on prescribing behavior of non-consultant hospital medical staff are largely informal . PrescriAside from prescribing habits, there are several other factors that influence hospital-based prescribing. Clinicians are faced on a daily basis with patients whose outcomes will be markedly improved if treated early with broad-spectrum antibiotics ,20. Manyet al. have described the implementation of an AMS program on the medical-surgical service of a 100-bed community hospital employing a core strategy of post-prescriptive audit with intervention and feedback. Their program, which had limited resources, was effective at reducing by 22% the defined daily doses of antimicrobials per 100 admissions [Hospital size will also influence AMS. Smaller hospitals or community-based hospitals may face major challenges developing and implementing AMS . Storey missions . Limitedmissions . Aside fmissions .Staphylococcus aureus infections [Prescribing is also influenced by ease and practicality. Both ease and practicality dictate that third-generation cephalosporins administered once daily are preferred over narrower spectrum penicillins (which require multiple daily doses or continuous infusion) in order to facilitate patient discharge in hospital-in-the-home programs. Ceftriaxone is a broad-spectrum cephalosporin with pharmacokinetic and antimicrobial characteristics that make it a good candidate for outpatient parenteral therapy ,29. Althfections . Third-gfections , and theIn hospitals, constraints over the rapidity of completing patient assessment and care in emergency departments may also result in prescribing of broad-spectrum antimicrobials. The introduction of a 4-hour rule into tertiary hospital emergency departments necessitates efficient completion of patient assessment and treatment. This 4-hour rule resulted in fewer deaths and a significant fall in mortality for patients admitted through those emergency departments ,33. Howeet al. found that the medical costs attributable to ARI ranged from $18,588 to $29,069 per patient with an excess duration of hospital stay of 6.4–12.7 days, and an attributable mortality of 6.5% [Supporting hospital-based AMS is expensive and given that many antimicrobials which stewardship seeks to restrict are now off patent and inexpensive, there are no major cost-savings of restriction that will offset the costs of an AMS program ,35,36. H of 6.5% . These sHowever, hospitals are only one location where antibiotics are used. Antimicrobial use is also high in residential aged care facilities where 2%–5% of people over the age of 65 years reside ,39. Withvs. 9%) [The elderly are more susceptible to infection due to transmission of infection within their residential environment, and primary and secondary immune dysfunction ,42. In avs. 9%) ,45. ThisHowever, despite international guidelines suggesting the implementation of AMS in long-term care setting , well-deNicolle and others found that antimicrobials were the most commonly prescribed systemic drugs in long term care facilities and that up to three-quarters of antibiotic prescriptions for residents were inappropriate over a decade ago . Since tIt is known that antimicrobial prescribing in residential aged care is often not based on culture-proven infections, but is rather undertaken to manage reported symptoms, and most antimicrobial courses are initiated by telephone orders . Recent Clostridium difficile tests. In contrast, the authors do describe an increase in the use of ceftriaxone and carbapenems. In terms of the cost of this type of AMS service, it can be difficult to calculate as many teams who provide such services are full-time employees of affiliated institutions [Jump and others have described their AMS program in a LTCF affiliated with a large urban Veterans Affairs (VA) medical center . Their Aitutions .et al. studied the prevalence of antimicrobial organisms in aged care facilities and found that in the 15 months before the study commenced, residents received antibiotics for 445 episodes, 44% of which did not fulfill the McGeer criteria for bacterial infection [The widespread and inappropriate use of antimicrobials in the LTCFs is partly due to difficulties in clinically assessing elderly patients ,57. Othenfection ,60. TheyAntimicrobial use in the community cannot be overlooked. Antibiotics are one of the most commonly prescribed drug classes worldwide, with considerable variation in outpatient antibiotic use between countries . AMS in In Europe, the European Surveillance of Antibiotic consumption (ESAC) collects comprehensive data about antibiotic consumption, which allows benchmarking, and is complemented by longitudinal and compositional data analyses . Data frViral respiratory tract infections drive antibiotic overprescribing in the outpatient setting, and this overprescribing is also influenced by patient demand and expectations ,65. In kversus 7% of the time when they did not think the parent wanted antimicrobials for their child [It has been shown that prescribing in the community can also be influenced by the doctor’s perception of parental expectations. A survey was conducted of 306 parents of children 2–10 years of age with the presenting complaints of ear pain, throat pain, cough, or congestion. The researchers found that physicians’ perceptions of parental expectations for antimicrobials were the only significant predictor of prescribing antimicrobials for conditions of presumed viral etiology. When physicians thought a parent wanted an antimicrobial, they prescribed them 62% of the time ir child .Community-wide AMS programs require governments to invest heavily in education for both prescribers and the “worried-well” in order to be effective. Advertising campaigns using all types of media forums have targeted raising awareness about the use of antibiotics. This has been exemplified well in Europe by national antibiotic awareness campaigns from the European Centre for Disease Prevention and Control (ECDC). Currently national campaigns take place in 29 European countries . SlogansNational campaigns are also underway in The United States of America, Canada and Australia. The United States Centers for Disease Control and Prevention’s campaign is entitled “Get Smart: Know when antibiotics work” . The CanStreptococcus pneumoniae in Iceland [In the 1990s, one of the first national campaigns to reduce antibiotic prescribing resulted in a decrease in antibiotic use and penicillin-resistant  Iceland . Since tStreptococcus pyogenes. Strong interdisciplinary leadership can be an important asset in developing national campaigns to target antimicrobial resistance. In Belgium, the Belgian Antibiotic Policy Coordination Committee (BAPCOC) established working groups composed of microbiologists, infectious diseases’ and infection control specialists, epidemiologists, general practitioners (GPs), pharmacists, nurses, veterinarians, basic researchers, public health experts and health economists. Using their combined expertise, multimedia campaigns were developed to promote the prudent use of antibiotics in the community, and surveillance programs on antibiotic use and resistance were established . Their met al. evaluated the impact of quinolone restriction on the antimicrobial resistance of E. coli urine isolates in a community setting [E. coli urine isolates in the periods before, during, and after implementation of a nationwide restriction on ciprofloxacin use. The restriction campaign resulted in a significant decrease in E. coli nonsusceptibility to quinolones, from a mean of 12% before the intervention period to a mean of 9% in the intervention period . They were also able to demonstrate that the reversal in antimicrobial resistance may be short-lived as the improved susceptibility pattern reversed immediately when quinolone consumption rose [There is now increasing evidence that community-based AMS of a variety of agents can result in improvements in antimicrobial resistance. Gottesman  setting . They asion rose .France used to be known for the highest rates of antibiotic use and pneumococcal resistance in Europe. In 2001, French policy makers and public health authorities developed a coordinated and multifaceted strategy. It involved a yearly campaign targeting the public via mass media, conveying the message that “Antibiotics Are Not Automatic” . In addition, they promoted both treatment guidelines and the use of the Streptococcal rapid antigen test. Primary care physicians were also targeted by one-on-one educational sessions (referred to as academic detailing). Using 90% complete national health insurance data for two winters before the campaign and five winters after the launch, they measured a decline of 26.5% in the number of antibiotic prescriptions. This exceeded their national target of a 25% reduction in prescribing. They also found that the greatest decrease in prescribing was observed in children and that the use of all antibiotic classes except fluoroquinolones decreased. The relative increase in fluoroquinolone use by 12.8% was identified and the researchers hypothesized that this may be explained by the choice of antibiotic becoming less appropriate for certain treatment indications .Aside from measuring antibiotic use and antimicrobial resistance, a multidisciplinary program in Sweden has been able to show that antibiotic use can be reduced without measurable negative consequences. Swedish Strategic Programme for the Rational Use of Antimicrobial Agents and Surveillance of Resistance (STRAMA) was initiated in Sweden in 1994 with a focus on inappropriate prescribing of antibiotics to children with respiratory tract infections and on the surveillance of resistance in pneumococci. Between 1993 and 1997 antibiotic prescribing was reduced by 22%, with the most pronounced reduction in children under six years of age. In addition, the national frequency of penicillin-non-susceptible pneumococci did not increase during the 1990s . STRAMA National antimicrobial stewardship campaigns are expensive however. In France, developing and conducting their campaign cost 500 million EUR (653 million USD) over six years. In Belgium, the program cost 400,000 EUR  per year, and in 2007 their annual budget was 7.8 million EUR (10.2 million USD). Without a more detailed cost-benefit analysis, this cost information is difficult to interpret. However, it is known that the reduction in antibiotic costs in France outweighed the cost of the public campaign to reduce prescribing .An assessment of cost issues relevant to national AMS programs must take into account the amount of money spent by the pharmaceutical industry to promote antibiotics. In the United States in 1998, it was estimated that pharmaceutical companies spent about US $1.6 billion to promote antibiotics, an amount that vastly exceeds any budget allocated to antibiotic restriction campaigns .Clostridium difficile infection (CDI). In Scotland, their program aimed to reduce the use of “C. diffogenic agents”, termed the “4 C’s antibiotics”. The antibiotics that they targeted for reduction were; cephalosporins, amoxicillin-clavulanic acid, clindamycin and ciprofloxacin, and they promoted the use of amoxicillin, co-trimoxazole, doxycycline, and gentamicin. Compared with 2008, there were 47,000 fewer antibiotic prescriptions, and the use of the 4 C’s decreased by 30%. There was also a 5% increase in the use of recommended antimicrobials over the study period. They were also able to demonstrate an impressive 42% reduction in the rate of CDI cases from 2006 to 2010 [Some of the more innovative campaigns aimed at reducing antibiotic use have used different outcome measures as their marker of success. The ideal outcome measure of antibiotic use is the incidence of  to 2010 .Antibiotic delay is a strategy that is used in the community and indeed should be encouraged. More use should be made of collecting samples for culture when it is thought that a prescription is justified. The majority of patients in general practice will not come to harm if a prescription is delayed overnight to allow time for initial culture, which may direct treatment .et al. describe instances when drug dose and/or schedule can be used to minimize the probability that mutants will take over the bacterial population [et al. describe the concept of antibiotic conservation, which involves the optimization of dosing regimens by choosing the dose and schedule that results in the antimicrobial exposure that will achieve the microbiological and clinical outcome desired while simultaneously suppressing emergence of resistance [Other strategies for better using existing antibiotics aim to optimize dosing, scheduling and duration. There is evidence of the influence of antibiotic duration on minimizing the development of antibiotic resistance. Drusano pulation . In addisistance . The autsistance .Clostridium difficile infection rates in Scotland, but their program has also been successful at improving the clinical management of infections through quality improvement methodology [A reduction in total antibiotic use and expenditure are impacts of AMS, which have been well demonstrated ,86,87,88hodology . Furtherhodology . Qualityhodology . Traditionally, AMS programs relied on manual methods combined with clinical oversight and intervention. However, the advent of improved modern health care information technology has offered the opportunity to expand the breadth, depth, and efficiency of AMS programs. Point-of-care access to current medical information is easily available to the practitioner through the use of smartphones, iPads, and other personal digital assistants . In addiExpert computer clinical decision support systems have been a very promising information technology advance . A sevenRecently, researchers in Minneapolis compared the appropriateness of antimicrobial courses ordered either with their computer decision support system or without such a system. They found that use of a decision support system was associated with significantly more appropriate antimicrobial prescribing . In addiHowever, this optimism must be balanced against potential pitfalls of electronic systems used in health care. Electronic health records are widely used in the United States, but many of these do not meet criteria for “meaningful use” ,100. OnlThe dissemination of well-constructed electronic decision support systems has not been broad to date, likely due to issues of cost, the requirement for compatibility with existing electronic systems, and the fact that such systems cannot stand-alone and be effective. Such technology to assist prescribing must be part of a broader framework of AMS with an engaged AMS team in order to have an impact. Staphylococcus aureus (MRSA), Clostridium difficile, and extended spectrum beta-lactamase (ESBL)-producing organisms [Rapid diagnostic testing (RDT), although not yet routine, is an important investment, which will likely contribute to a reduction in antibiotic use. RDT allows for rapid identification of group A streptococcus, human immunodeficiency virus (HIV), and bacteria such as methicillin-resistant rganisms ,107,108.Rapid diagnostics are still predominantly performed in a laboratory. Such tests include; direct microscopy of specimens; antigen detection tests (such as enzyme immunoassay); molecular detection (nucleic acid probes and nucleic acid amplification); rapid biochemical tests (such as nitrite and leukocyte esterase performed on a urine dipstick); and serologic testing .Rapid and accurate diagnosis of an infection should enhance patient outcome by enabling early initiation of appropriate therapy and implementation of relevant infection control measures, and reducing unnecessary antimicrobial treatment. In particular, molecular tests such as multiplex-PCR or a DNA-based microarray platform for detection of organisms causing sepsis have been developed and hold promise for rapid diagnosis of bacterial sepsis ,104. DesClinicians can also utilize serum markers in order to decide whether antibiotics ought to be prescribed in a given patient. C-Reactive protein (CRP) is an acute-phase reactant, and CRP level measurements are frequently used to aid in the diagnosis of bacterial infections . In addiPreventing, reducing, and controlling the emergence of antimicrobial-resistant organisms is a major public health challenge that requires the participation of the entire medical community and public health agencies . AMS ini


To investigate whether the availability of a core conceptual component (color) affects lexical access in language production, we conducted two experiments on the naming of visually presented HCD and LCD objects. Experiment 1 showed that, when naming latencies were matched for colored HCD and LCD objects, achromatic HCD objects were named more slowly than achromatic LCD objects. In Experiment 2 we recorded ERPs while participants performed a picture-naming task, in which achromatic target pictures were either preceded by an appropriately colored box (primed condition) or a black and white checkerboard (unprimed condition). We focused on the P2 component, which has been shown to reflect difficulty of lexical access in language production. Results showed that HCD resulted in slower object-naming and a more pronounced P2. Priming also yielded a more positive P2 but did not result in an RT difference. ERP waveforms on the P1, P2 and N300 components showed a priming by color-diagnosticity interaction, the effect of color priming being stronger for HCD objects than for LCD objects. The effect of color-diagnosticity on the P2 component suggests that the slower naming of achromatic HCD objects is (at least in part) due to more difficult lexical retrieval. Hence, the color attribute seems to affect lexical retrieval in HCD words. The interaction between priming and color-diagnosticity indicates that priming with a feature hinders lexical access, especially if the feature is a core feature of the target object.According to frame-theory, concepts can be represented as structured frames that contain conceptual attributes  and their values . A particular color value can be seen as a core conceptual component for ( This view on conceptual representation has been adopted by some models of lexical access , which in itself does not include features of the concept but is connected to conceptual nodes such as female and parent via conceptual relations. In terms of lexical access, non-decompositional accounts assert that each lemma node is connected to and activated by a single conceptual node. Note that decompositional and non-decompositional semantics often make the same predictions and are difficult to tease apart. A recent attempt to model the cumulative semantic inhibition effect showed no differences when either decompositional or non-decompositional semantics were assumed , structural invariants  and constraints . The frame of the concept lemon, for example, comprises information about its shape, taste, surface texture and color, and about where and how it is cultivated. Some of this information might be activated whenever the concept is activated (core features), other information can be dependent on the linguistic context , or also to single attributes ? By contrasting the predictions made by decompositional and non-decompositional models of language production in this manner, we hope to contribute to a further refinement of frame-theory.The question of (non-)decompositionality of lexical selection is important for theories that try to model conceptual representations as frames  objects being more strongly associated to a particular, typical color than low color-diagnostic (LCD) objects. A number of behavioral and neurophysiological studies suggest that color contributes to object recognition in various tasks, including picture-naming  and a more peripheral feature for others , or a black-and-white checkerboard (unprimed condition). Following decompositional views of conceptual representation, pre-activation of a feature should facilitate lexical access, because single features should have access to the lemma node. This would predict a less pronounced P2 and shorter reaction times for primed, HCD objects than for unprimed, HCD objects. Furthermore, we would expect no  effect of pre-activation of the color feature on LCD objects, resulting in no  differences in reaction times and P2 amplitude between primed and unprimed conditions. Non-decompositional models, on the other hand, would predict no positive priming effect on HCD or LCD objects, because only the conceptual node has access to the lemma node, whereas the feature nodes connected to it do not. Frame theories could predict different outcomes depending on how they model connections between lemma nodes, concepts, and conceptual components: On the one hand, it could be possible that a single feature can be pre-activated and subsequently facilitate lexical access of, in particular, HCD objects, for which color is a core feature in the frame. On the other hand, single features might only be activated together with the whole concept, making it impossible to pre-activate them in a priming paradigm. In this case, no priming effect on HCD or LCD objects would be expected.Secondly, to explore whether (1) the activation of a single feature within an object's frame can impact the retrieval of that object's lexical information, and (2) whether this effect can be modulated by the fact that a feature is either core or peripheral to the object in question, we conducted a second experiment using the same stimuli as in Experiment 1. We presented the achromatic stimuli in a semantic priming paradigm preceded by appropriately colored boxes as visual prime  took part in the experiment. All participants were right-handed native speakers of Dutch with normal or corrected-to-normal vision and no color vision impairments and received course credits or money as a reward for participation.Thirty-two participants . HCD and LCD items were also matched for luminance , visual complexity  and name agreement .To determine which items should be categorized as HCD and LCD, an online survey was conducted, in which 17 participants rated the appropriateness of the chosen color and the color-diagnosticity of each item by answering the following questions: “Does this object have one or more typical colors?,” “How many different colors can this object have?” and “If there is a typical color, is it the one displayed here? If not, please name the color.” On the basis of the results, the items were grouped into two sets of HCD and LCD objects. In cases where participants indicated that an item could have “one or more typical colors,” but did not agree on a common typical color in the comment field , the item was classified as LCD. HCD and LCD items were matched for frequency and word length across sets by using lemma frequencies obtained from Each item was shown only once to each participant. The two groups of HCD and LCD items were split in two, so that each item was presented in color to 16 participants (colored presentation mode), whereas the other 16 participants saw the achromatic version (achromatic presentation mode). We combined these items to two lists. All items shown as colored versions in list 1 (presented to 16 participants) were shown as achromatic versions in list 2 (presented to 16 other participants). The two lists were each split into four parts, which were then pseudo-randomized using the Shuffle software Pallier,  and recowww.neurobs.com). All pictures were presented measuring 242 by 242 px. The participants' verbal responses were recorded as wav files. Voice onset times were determined offline using Praat  with color-diagnosticity (HCD and LCD) and presentation mode (achromatic and colored) as within-subject factors, and using a significance criterion of F = 18.764, p < 0.001, η2 = 0.377; see Figure F = 9.232, p = 0.005, η2 = 0.229). Naming latencies for HCD items were longer  than for LCD items  when they were presented in gray-scale, but only a smaller difference was found between HCD and LCD objects when they were presented in color . Further, HCD items were recognized faster in color than in gray-scale. There was no difference for LCD items between colored and achromatic presentation mode. Trials classified as errors according to the criteria described above were excluded from the reaction time analysis . An ANOVA with error rate as dependent variable showed no significant main effects or interactions (p > 0.05).We found a significant main effect of presentation mode . There were no other main effects or interactions (p > 0.05).Erroneous trials were defined according to the criteria mentioned above . Similar to the pattern found in the reaction time analysis, error rates were significantly higher for HCD items compared to LCD items, . Further, we observed a color-diagnosticity by priming by laterality interaction . On left electrode sites, HCD items  were more affected by priming than LCD items .F = 12.734, p = 0.001, η2 = 0.291] and priming . Further, we found an interaction between priming and laterality , as well as a three-way interaction between priming, laterality and anteriority . At both left and right electrodes, the difference between primed and unprimed was smaller at the midline than at frontal and posterior sites. We also observed interactions between color-diagnosticity, priming and anteriority , and between color-diagnosticity, priming, and laterality , showing that priming had a stronger influence on HCD items compared to LCD items particularly on posterior  and central sites .180–300 ms: In this time-window, the ANOVA yielded main effects of color-diagnosticity . At central electrodes, waveforms elicited by primed, HCD items  were less negative than those elicited by unprimed, HCD items , whereas there was a smaller difference between primed and unprimed LCD objects .F = 12.065, p = 0.002, η2 = 0.280] and priming . LCD and unprimed items resulted in more negative waveforms compared to HCD and primed items.140–190 ms: In this time-window, we observed main effects of color-diagnosticity  and priming . HCD items and primed items elicited more positive waveforms than LCD and unprimed items. We also observed an interaction between priming and laterality , showing that the priming effect was stronger on central and left electrode sites compared to right sites. There was a trend toward an interaction between color-diagnosticity, priming, and laterality , indicating that HCD items were particularly affected by priming compared to LCD items at central electrodes .200–250 ms: Significant main effects were present for color-diagnosticity  and priming . HCD and primed items resulted in more positive waveforms compared to LCD and unprimed items. Further, there was an interaction between color-diagnosticity, priming, and laterality . Particularly at central electrodes, there was a larger difference between primed, HCD  and unprimed, HCD conditions  than there was between primed  and unprimed  LCD conditions.250–380 ms: In this time-window, the ANOVA yielded main effects of color-diagnosticity . At left electrode sites, HCD items  were particularly affected by priming compared to LCD items , primed items resulting in a larger negativity than unprimed items.F = 5.761, p = 0.023, η2 = 0.157] and priming . HCD conditions elicited more positive waveforms compared to LCD conditions. We also observed an interaction between priming and laterality , the difference between primed and unprimed items being most pronounced at central electrodes. Further, there was an interaction between color-diagnosticity, priming and laterality , showing that at central electrodes, priming had a stronger effect on HCD items  than it had on LCD items .180–300 ms: We found significant main effects of color-diagnosticity [In Experiment 2, we found a behavioral effect of color-diagnosticity (HCD items were produced on average 31 ms slower than LCD items), but no effect of priming. The ERPs revealed an early interaction between color-diagnosticity and priming in the 100–140 ms time-window, where ERPs elicited for primed HCD items elicited the most pronounced P1. In the three following time-windows, both priming and HCD resulted in a more positive waveform. We observed further interactions between color-diagnosticity and priming on the P2 at fronto-central electrodes (180–300 ms), and a trend for an interaction in the same direction at posterior electrodes (200–250 ms). The P2, which has been shown to be an index of difficulty of lexical retrieval by, e.g., Strijkers et al. , was mosOur behavioral results in Experiment 1 showed that achromatic versions of HCD objects were named more slowly than colored versions of HCD objects, whereas no such difference was found between colored and achromatic presentations of LCD objects. In Experiment 2, HCD resulted not only in slower object naming, but also a more positive P2 component. Priming also elicited a more pronounced P2 component, but had no effect on naming latencies. Lastly, the effect of priming was stronger for HCD objects than for LCD objects, as revealed by an interaction between priming and color-diagnosticity in early (P1) and later processing stages (P2 and N300). The interaction between color-diagnosticity and priming on the P1 held irrespective of whether electrodes on the whole scalp were considered or only electrodes belonging to either frontal and central or posterior sites. The interaction effect on the P2 was most evident in the whole scalp analysis in the 180–300 ms time-window and on frontal and central electrode sites. The effect also approached significance when we analyzed the isolated P2 peak on posterior sites. In all three time-windows, waveforms for HCD items were more pronounced for primed compared to unprimed conditions, whereas smaller differences between primed and unprimed LCD items were found.The P1-N1 complex has been associated with visual processing  items where there are fewer visual similarities . This difference might have consequences for lexical access: More competing lemmas are activated for HCD objects, making selection of the right lemma more difficult. For LCD objects, there are less competitors, or their competitors are not as strongly activated . Therefore, activation levels of competitors for lexical access are not increased as much for LCD items. Thus, similar to previous studies . It is also possible that color priming can be detrimental to picture naming if the color chosen as visual prime does not fully correspond to the individual participant's specific representation of the color in the object's frame. The color shown to pre-activate the target strawberry, for instance, might correspond more closely to the value of the color feature present in the individual participant's frame for tomato, thus activating the concept tomato . This increase of competition at the conceptual level would consequently influence lexical retrieval at a later stage as reflected in a more pronounced P2 for primed items. This interpretation is, of course, contingent upon the magnitude of the P2 being an index of the effort involved in the lexical retrieval process, which is well supported by the currently available literature . Subtle differences between primed and unprimed conditions may, thus, be lost due to a ceiling effect and might only be visible in the ERPstomato, strawberry, raspberry, or cherry). Alternatively, if we interpret the main effect of priming as a result of a discrepancy between the color prime and the mental representation of the color feature, this could also account for the interaction between color-diagnosticity and priming. The difference between the color of the prime and the represented color might place additional processing demands on lexical retrieval of HCD objects, for which color is an important visual cue. Consequently, the lexical representations of HCD objects would be more difficult to retrieve compared to those of LCD objects. The present data, however, cannot distinguish between these lines of explanation.Following the interpretation of the main effects of priming and color-diagnosticity outlined above, it seems plausible that the interaction between color-diagnosticity and priming on the P2 indicates that priming has an influence on lexical access of, in particular, HCD objects. This could be explained by increased lexical competition: priming with a color box creates lexical competition by activating concepts associated with that particular color. This competition is largest in the case of HCD items, where the competition between similar concepts activated by a particular color prime might be stronger than for LCD items  matched the typical color of the target picture , Bramão et al. , participants may, for instance, attempt a matching between the prime's color and the target's color attribute as an additional conceptual monitoring process . This is to be distinguished from processes operating at the lemma level as such (which we consider to be indexed by the P2).In summary, previous research suggests that the N300 reflects the processing of visual semantic features. These findings fit well with the interaction between color-diagnosticity, priming and laterality that we found in the N300 time-window. HCD, primed items elicited the most positive-going waveform compared to our other experimental conditions, suggesting that the additional color information provided by the color prime places greater demands on visual semantic processing for, in particular, HCD items. Further studies are necessary to determine the exact locus of the N300 component within the language production process but, whether or not the N300 reflects lexical or post-lexical processing, the observed interactions between color-diagnosticity and priming on the N300 and the earlier P2 have interesting implications for how we conceive of color representations in object frames.lemon. Further experiments testing the second explanation might therefore adjudicate on the necessity of frame-theoretical representations.Following decompositional views of semantic representations, conceptual features (such as a particular color in the case of HCD objects) should have access to the lemma node of the corresponding concept. Thus, activation of these features would be beneficial for lexical retrieval. This account would predict a facilitatory effect of priming on HCD objects, for which color is a relevant feature. LCD objects, which do not have a typical color, should not be affected by color priming. These predictions do not fit with our results, which showed a detrimental, rather than facilitatory, effect of priming on HCD objects. Our results are compatible with a classic non-decompositional view or with a frame-theoretical view, in which an object's attributes are only accessed via its corresponding conceptual node and cannot themselves activate the object's lexical lemma. Both accounts would not predict a facilitatory effect of color primes because only concept nodes  have access to the relevant lemma. Although both accounts as such would not predict the observed inhibitory effect of color primes on HCD objects, the interaction between priming and color-diagnosticity found in the ERPs could be explained (1) by additional lexical competition or (2) by interference with the activation of HCD concepts due to a mismatch between stored and perceived color. Based on the present data, it is not possible to distinguish between these two possible explanations. Note, however, that the second explanation relies on frame-theoretical conceptual representations allowing for a specification of the particular shade of a color of a particular concept, e.g., the yellow of a Taken together, our results show that lexical access of, in particular, HCD objects, is hindered by the presence of a color prime. This finding indicates that, contrary to decompositional accounts of semantic representations, there is no direct link between the conceptual features of an object (such as color) and its corresponding lemma node. Our findings have consequences for frame-theoretical accounts of conceptual representations, namely that only the central node of a concept should be used for lexical access. Further, the interaction between priming and color-diagnosticity in the N300 time-window might suggest the additional involvement of a monitoring process that assesses the fit of available visual semantic features.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.