Flu and pertussis vaccination during pregnancy in Geneva during the COVID-19 pandemic: A multicentric, prospective, survey-based study.

OBJECTIVE: To determine pertussis and influenza vaccination coverage during pregnancy among women delivering in all the maternities of Geneva (Switzerland), during the COVID-19 pandemic. METHODS: All women delivering in all the maternity centres of the canton of Geneva from 1st November 2020 to 30th November 2020 (beginning of the flu vaccination season) and from 8th March 2021 to 7th April 2021 (end of the flu vaccination season) had their records checked upon admission to the labour ward regarding pertussis and influenza vaccination during pregnancy. Reasons for non-vaccination were recorded. Univariate and multivariate analyses were done to identify predictors of vaccine uptake. RESULTS: 951 women delivered in Geneva during the two study periods, of which 950 were included in the study. 86.2% were vaccinated against pertussis, with no significant difference between the study periods (87.5% vs 85% at the beginning and end of the flu vaccination season respectively). 49.8% were vaccinated against influenza, with no significant difference between the study periods (48.8% vs 50.7% beginning and end of the flu vaccination season respectively). The influenza vaccine was 5 times more likely not to be proposed (8.9% vs. 1.7%) and 3 times more likely to be refused (26.6% vs. 8%) than the pertussis vaccine. Main reason for refusal was a lack of maternal desire for both vaccines, but not vaccine fear. Maternal parity ≥ 1 was significantly associated with pertussis vaccine uptake at univariate analysis. Women were significantly more likely to accept the influenza vaccine if they had a university degree or if they did not deliver in a midwife-only run delivery unit in both univariate and multivariate analysis. CONCLUSIONS: In Geneva, most gynaecologists offer pertussis immunization during antenatal care and uptake is high, but more efforts must be done to increase influenza vaccination coverage. Education level impacts maternal flu vaccination uptake, but other social disparities did not.

Beneficial Effect of IL-4 and SDF-1 on Myogenic Potential of Mouse and Human Adipose Tissue-Derived Stromal Cells.

Under physiological conditions skeletal muscle regeneration depends on the satellite cells. After injury these cells become activated, proliferate, and differentiate into myofibers reconstructing damaged tissue. Under pathological conditions satellite cells are not sufficient to support regeneration. For this reason, other cells are sought to be used in cell therapies, and different factors are tested as a tool to improve the regenerative potential of such cells. Many studies are conducted using animal cells, omitting the necessity to learn about human cells and compare them to animal ones. Here, we analyze and compare the impact of IL-4 and SDF-1, factors chosen by us on the basis of their ability to support myogenic differentiation and cell migration, at mouse and human adipose tissue-derived stromal cells (ADSCs). Importantly, we documented that mouse and human ADSCs differ in certain reactions to IL-4 and SDF-1. In general, the selected factors impacted transcriptome of ADSCs and improved migration and fusion ability of cells in vitro. In vivo, after transplantation into injured muscles, mouse ADSCs more eagerly participated in new myofiber formation than the human ones. However, regardless of the origin, ADSCs alleviated immune response and supported muscle reconstruction, and cytokine treatment enhanced these effects. Thus, we documented that the presence of ADSCs improves skeletal muscle regeneration and this influence could be increased by cell pretreatment with IL-4 and SDF-1.

IL-4 and SDF-1 Increase Adipose Tissue-Derived Stromal Cell Ability to Improve Rat Skeletal Muscle Regeneration.

Skeletal muscle regeneration depends on the satellite cells, which, in response to injury, activate, proliferate, and reconstruct damaged tissue. However, under certain conditions, such as large injuries or myopathies, these cells might not sufficiently support repair. Thus, other cell populations, among them adipose tissue-derived stromal cells (ADSCs), are tested as a tool to improve regeneration. Importantly, the pro-regenerative action of such cells could be improved by various factors. In the current study, we tested whether IL-4 and SDF-1 could improve the ability of ADSCs to support the regeneration of rat skeletal muscles. We compared their effect at properly regenerating fast-twitch EDL and poorly regenerating slow-twitch soleus. To this end, ADSCs subjected to IL-4 and SDF-1 were analyzed in vitro and also in vivo after their transplantation into injured muscles. We tested their proliferation rate, migration, expression of stem cell markers and myogenic factors, their ability to fuse with myoblasts, as well as their impact on the mass, structure and function of regenerating muscles. As a result, we showed that cytokine-pretreated ADSCs had a beneficial effect in the regeneration process. Their presence resulted in improved muscle structure and function, as well as decreased fibrosis development and a modulated immune response.

Transient MicroRNA Expression Enhances Myogenic Potential of Mouse Embryonic Stem Cells.

MicroRNAs (miRNAs) are known regulators of various cellular processes, including pluripotency and differentiation of embryonic stem cells (ESCs). We analyzed differentiation of two ESC lines-D3 and B8, and observed significant differences in the expression of miRNAs and genes involved in pluripotency and differentiation. We also examined if transient miRNA overexpression could serve as a sufficient impulse modulating differentiation of mouse ESCs. ESCs were transfected with miRNA Mimics and differentiated in embryoid bodies and embryoid body outgrowths. miRNAs involved in differentiation of mesodermal lineages, such as miR145 and miR181, as well as miRNAs regulating myogenesis (MyomiRs)-miR1, miR133a, miR133b, and miR206 were tested. Using such approach, we proved that transient overexpression of molecules selected by us modulated differentiation of mouse ESCs. Increase in miR145 levels upregulated Pax3, Pax7, Myod1, Myog, and MyHC2, while miR181 triggered the expression of such crucial myogenic factors as Myf5 and MyHC2. As a result, the ability of ESCs to initiate myogenic differentiation and form myotubes was enhanced. Premature expression of MyomiRs had, however, an adverse effect on myogenic differentiation of ESCs. Stem Cells 2018;36:655-670.

Percepción factores psicosociales y del entorno relacionados con el desplazamiento activo / Perception of psychosocial and environmental factors related to active displacement

El desplazamiento activo, bien caminando o en bicicleta, contribuye a incrementar el nivel de actividad física de las personas. Este hábito podría favorecerse actuando sobre ciertos factores psicosociales, y creando entornos próximos propicios. El propósito del presente trabajo fue determinar la percepción de los factores individuales y del entorno próximo, relacionados de forma especial, con cada una de las dos modalidades de desplazamiento, en una muestra poblacional de las personas adultas que residen en el área metropolitana de Pamplona. Se realizó un estudio transversal basado en la metodología propuesta por el Internacional Physical Activity and the Environment Network Adult Group, que estudia la relación entre los factores del entorno y la actividad física que practican las personas adultas. Los resultados obtenidos muestran que la falta de tiempo para practicar actividad física se asoció con mayor probabilidad con el grupo que menos se desplazó caminando, OR 1.23(1.08-1,.40), y la falta de disfrute de la actividad física con el que menos se desplazó en bicicleta, OR 1.29(1.04-1.61). Asimismo, la existencia de arbolado en las calles se asoció con mayor probabilidad de desplazarse caminando, OR 1.23(1.03-1.46), mientras que la presencia de señales o pasos, que ayudaran a cruzar a los peatones, se relacionó con mayor probabilidad de utilizar bicicleta, OR 1.42(1.08 -1.87). En conclusión, determinadas características individuales y del entorno se asocian particularmente con los desplazamientos caminando mientras que otras, lo hacen con el uso de bicicleta. Así, las personas que dedican menos tiempo a caminar para desplazase señalan la falta de tiempo como el motivo que les impide realizar actividad física, mientras que el grupo que menos usa la bicicleta para desplazarse indica la falta de disfrute. Además, la presencia de árboles en las aceras favorece y anima a las personas a realizar los desplazamientos caminando y la percepción de tráfico intenso se asocia con el grupo que menos tiempo dedica a caminar para desplazarse de un lugar a otro. Sin embargo, el desarrollo de infraestructuras que faciliten la movilidad de los peatones se asocia con mayor uso de la bicicleta para los desplazamientos

The active transport, whether walking or cycling, contributes to increasing the level of physical activity of people. This habit could be favoured by acting on certain psychosocial factors, and by creating favourable environments. The purpose of the present study was to determine the perception of individual factors and of the nearby environment, related in a special way to each of the two modalities of active transport, in a population sample of the adults living in the metropolitan area of Pamplona. A cross-sectional study was conducted based on the methodology suggested by the International Physical Activity and the Environment Network Adult Group, which studies the relationship between environmental factors and physical activity practiced by adults. The results showed that the lack of time to practice physical activity was more likely to be associated with the group that walked less, OR 1.23 (1.08-1.40), and the lack of enjoyment of the physical activity with those who transport by bicycle less, OR 1.29 (1.04-1.61). Also, the existence of trees in the streets was associated with a greater probability of transport by walking, OR 1.23 (1.03-1.46), while the presence of signs or zebra crossings, which helped pedestrians to cross, was related to a wider use of the bycicle, OR 1.42 (1.08 -1.87). In conclusion, certain characteristics of the individual and the environment are particularly associated with walking while others are with the use of the bicycle. Thus, people who spend less time walking to go from one place to another indicate lack of time as the reason that prevents them from carrying out some physical activity, while the group that uses the bicycle less to transport indicates lack of enjoyment. In addition, the presence of trees on the pavements favours and encourages people to travel by walking and the perception of intense traffic is associated with the group that dedicates less time to walking in order to go from one place to another. However, developing infrastructures that facilitate the mobility of pedestrians is associated with a greater use of the bicycle for active transport

Myogenic potential of mouse embryonic stem cells lacking functional Pax7 tested in vitro by 5-azacitidine treatment and in vivo in regenerating skeletal muscle.

Regeneration of skeletal muscle relies on the presence of satellite cells. Satellite cells deficiency accompanying some degenerative diseases is the reason for the search for the "replacement cells" that can be used in the muscle therapies. Due to their unique properties embryonic stem cells (ESCs), as well as myogenic cells derived from them, are considered as a promising source of therapeutic cells. Among the factors crucial for the specification of myogenic precursor cells is Pax7 that sustains proper function of satellite cells. In our previous studies we showed that ESCs lacking functional Pax7 are able to form myoblasts in vitro when differentiated within embryoid bodies and their outgrowths. In the current study we showed that ESCs lacking functional Pax7, cultured in vitro in monolayer in the medium supplemented with horse serum and 5azaC, expressed higher levels of factors associated with myogenesis, such as Pdgfra, Pax3, Myf5, and MyoD. Importantly, skeletal myosin immunolocalization confirmed that myogenic differentiation of ESCs was more effective in case of cells lacking Pax7. Our in vivo studies showed that ESCs transplanted into regenerating skeletal muscles were detectable at day 7 of regeneration and the number of Pax7-/- ESCs detected was significantly higher than of control cells. Our results support the concept that lack of functional Pax7 promotes proliferation of differentiating ESCs and for this reason more of them can turn into myogenic lineage.

Cell cycle regulation of embryonic stem cells and mouse embryonic fibroblasts lacking functional Pax7.

The transcription factor Pax7 plays a key role during embryonic myogenesis and in adult organisms in that it sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Recently we have shown that lack of Pax7 does not prevent the myogenic differentiation of pluripotent stem cells. In the current work we show that the absence of functional Pax7 in differentiating embryonic stem cells modulates cell cycle facilitating their proliferation. Surprisingly, deregulation of Pax7 function also positively impacts at the proliferation of mouse embryonic fibroblasts. Such phenotypes seem to be executed by modulating the expression of positive cell cycle regulators, such as cyclin E.

Influence of Urbanistic Characteristics in the Level of Physical Activity in People Aged 18 to 65 of the Metropolitan Area Pamplona, Spain. / Influencia de las características urbanísticas ambientales en el nivel de actividad física de la población de 18 a 65 años del área metropolitana de Pamplona. rorzancg@cfnavarra.es.

BACKGROUND: A suitable environment can encourage the practice of physical activity, being an easy option for the population, for this reason the main objective was to determine the influence of the urban environmental characteristics relate with the physical activity on adult people living on the Pamplona Area. METHODS: Cross-sectional study based on the International Physical Activity and the Environment Network (IPEN Adult). Participants were selected in random and stratified from the Basic areas of health attached to resident's population in the Pamplona area, aged ranged between 18-65years old. A self-administered questionnaire was used, including a complete version of the Neighborhood Environment Walkability Scale scale, to evaluate the perception of the urban environmental factors. In addition, the extended version of International Physical Activity Questionnaire for the physical activity data collection was employed. Chi square test was calculated and a multi variable analysis using non-conditional logistic regression. RESULTS: The representative sample was composed of 905 subjects, [54,70% female]. The perception of having footpaths near to their place of resident or workplace was greater in the group that practice moderated physical activity OR: 3,86 [CI95% 1.70-8.74] and greater total physical activity (the summary of vigorous, moderated physical activity and walking) (OR: 2,61 [CI95% 1.24-5.45]). The people perception of having many places for walk in the neighborhood was associated with major habit of taking a walk (OR: 1,26 [IC95% 1.01-1.58]. Having sport spaces close to the workplace or place of resident was associated with major practice of vigorous physical s activity, OR: 1,46 [CI95% 1.01-2.12]. CONCLUSIONS: There is a direct association between the practice of physical activity and environmental urban characteristics, such as the existence of paths of walk or sports facilities.

OBJETIVO: Un entorno adecuado puede favorecer la práctica de la actividad física, siendo una opción fácil para la población. El objetivo fue determinar la influencia de la percepción de los factores urbanísticos ambientales en el nivel de actividad física de las personas adultas. METODOS: Estudio transversal basado en el International Physical Activity and the Environment Network. Las personas participantes fueron seleccionadas de forma aleatoria y estratificada de la población de las zonas básicas de salud del Área Metropolitana de Pamplona entre las que tenían edad de 18 a 65 años. Se utilizó un cuestionario autoadministrado que incluyó la versión completa de la escala Neighborhood Environment Walkability Scale para valorar la percepción de los factores urbanísticos ambientales y la versión larga del International Physical Activity Questionnaire para recoger datos de actividad física. Se calculó la chi2 y se realizó un análisis multivariable mediante regresión logística no condicional. RESULTADOS: Participaron 905 sujetos (54,70% mujeres). Tener sendas de paseo próximas al domicilio o lugar de trabajo se relacionó con practicar actividad física moderada OR: 3,86 (IC 95% 1,70-8,74)] y actividad física total (suma de actividad física vigorosa, moderada y caminar) OR: 2,61 (IC 95% 1,24-5,45)]. La presencia en el barrio de lugares a los que podían ir caminando se asoció con dedicar más tiempo a caminar [OR: 1,26 (IC 95% 1,01-1,58)] y disponer cerca del domicilio o lugar de trabajo de espacios deportivos se asoció con practicar más actividad física vigorosa [OR: 1,46 (IC 95% 1,01 - 2,12). CONCLUSIONES: Existe asociación directa entre la práctica de la actividad física y las características urbanísticas ambientales, como la existencia de sendas de paseo o instalaciones deportivas.

Myogenic Differentiation of Mouse Embryonic Stem Cells That Lack a Functional Pax7 Gene.

The transcription factor Pax7 plays a key role during embryonic myogenesis and sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Overexpression of Pax7 has been shown to promote the myogenic differentiation of pluripotent stem cells. However, the effects of the absence of functional Pax7 in differentiating embryonic stem cells (ESCs) have not yet been directly tested. Herein, we studied mouse stem cells that lacked a functional Pax7 gene and characterized the differentiation of these stem cells under conditions that promoted the derivation of myoblasts in vitro. We analyzed the expression of myogenic factors, such as myogenic regulatory factors and muscle-specific microRNAs, in wild-type and mutant cells. Finally, we compared the transcriptome of both types of cells and did not find substantial differences in the expression of genes related to the regulation of myogenesis. As a result, we showed that the absence of functional Pax7 does not prevent the in vitro myogenic differentiation of ESCs.

Influencia de las características urbanísticas ambientales en el nivel de actividad física de la población de 18 a 65 años del área metropolitana de Pamplona / Influence of urbanistic characteristics in the level of physical activity in people aged 18 to 65 of the metropolitan area Pamplona, Spain

Fundamentos: Un entorno adecuado puede favorecer la práctica de la actividad física, siendo una opción fácil para la población. El objetivo fue determinar la influencia de la percepción de los factores urbanísticos ambientales en el nivel de actividad física de las personas adultas. Métodos: Estudio transversal basado en el International Physical Activity and the Environment Network. Las personas participantes fueron seleccionadas de forma aleatoria y estratificada de la población de las zonas básicas de salud del Área Metropolitana de Pamplona entre las que tenían edad de 18 a 65 años. Se utilizó un cuestionario autoadministrado que incluyó la versión completa de la escala Neighborhood Environment Walkability Scale para valorar la percepción de los factores urbanísticos ambientales y la versión larga del International Physical Activity Questionnaire para recoger datos de actividad física. Se calculó la chi2 y se realizó un análisis multivariable mediante regresión logística no condicional. Resultados: Participaron 905 sujetos (54,70% mujeres). Tener sendas de paseo próximas al domicilio o lugar de trabajo se relacionó con practicar actividad física moderada OR: 3,86 (IC 95% 1,70-8,74)] y actividad física total (suma de actividad física vigorosa, moderada y caminar) OR: 2,61 (IC 95% 1,24-5,45)]. La presencia en el barrio de lugares a los que podían ir caminando se asoció con dedicar más tiempo a caminar [OR: 1,26 (IC 95% 1,01-1,58)] y disponer cerca del domicilio o lugar de trabajo de espacios deportivos se asoció con practicar más actividad física vigorosa [OR: 1,46 (IC 95% 1,01 - 2,12). Conclusiones: Existe asociación directa entre la práctica de la actividad física y las características urbanísticas ambientales, como la existencia de sendas de paseo o instalaciones deportivas (AU)

Background: A suitable environment can encourage the practice of physical activity, being an easy option for the population, for this reason the main objective was to determine the influence of the urban environmental characteristics relate with the physical activity on adult people living on the Pamplona Area. Methods: Cross-sectional study based on the International Physical Activity and the Environment Network (IPEN Adult). Participants were selected in random and stratified from the basic areas of health attached to resident’s population in the Pamplona area, aged ranged between 18-65years old. A self-administered questionnaire was used, including a complete version of the Neighborhood Environment Walkability Scale scale, to evaluate the perception of the urban environmental factors. In addition, the extended version of International Physical Activity Questionnaire for the physical activity data collection was employed. Chi2 test was calculated and a multi variable analysis using non-conditional logistic regression. Results: The representative sample was composed of 905 subjects, [54,70% female]. The perception of having footpaths near to their place of resident or workplace was greater in the group that practice moderated physical activity OR: 3,86 [CI95% 1.70-8.74] and greater total physical activity (the summary of vigorous, moderated physical activity and walking) (OR: 2,61 [CI95% 1.24-5.45]). The people perception of having many places for walk in the neighborhood was associated with major habit of taking a walk (OR: 1,26 [IC95% 1.01-1.58]. Having sport spaces close to the workplace or place of resident was associated with major practice of vigorous physical s activity, OR: 1,46 [CI95% 1.01-2.12]. Conclusions: There is a direct association between the practice of physical activity and environmental urban characteristics, such as the existence of paths of walk or sports facilities (AU)

Adhesion proteins--an impact on skeletal myoblast differentiation.

Formation of mammalian skeletal muscle myofibers, that takes place during embryogenesis, muscle growth or regeneration, requires precise regulation of myoblast adhesion and fusion. There are few evidences showing that adhesion proteins play important role in both processes. To follow the function of these molecules in myoblast differentiation we analysed integrin alpha3, integrin beta1, ADAM12, CD9, CD81, M-cadherin, and VCAM-1 during muscle regeneration. We showed that increase in the expression of these proteins accompanies myoblast fusion and myotube formation in vivo. We also showed that during myoblast fusion in vitro integrin alpha3 associates with integrin beta1 and ADAM12, and also CD9 and CD81, but not with M-cadherin or VCAM-1. Moreover, we documented that experimental modification in the expression of integrin alpha3 lead to the modification of myoblast fusion in vitro. Underexpression of integrin alpha3 decreased myoblasts' ability to fuse. This phenomenon was not related to the modifications in the expression of other adhesion proteins, i.e. integrin beta1, CD9, CD81, ADAM12, M-cadherin, or VCAM-1. Apparently, aberrant expression only of one partner of multiprotein adhesion complexes necessary for myoblast fusion, in this case integrin alpha3, prevents its proper function. Summarizing, we demonstrated the importance of analysed adhesion proteins in myoblast fusion both in vivo and in vitro.

Sdf-1 (CXCL12) improves skeletal muscle regeneration via the mobilisation of Cxcr4 and CD34 expressing cells.

BACKGROUND INFORMATION: The regeneration of skeletal muscles involves satellite cells, which are muscle-specific precursor cells. In muscles, injured either mechanically or as a consequence of a disease, such as muscular dystrophy, local release of the growth factors and cytokines leads to satellite cells activation, proliferation and differentiation of the resulting myoblasts, followed by the formation of new myofibres. Various cell types, such as stem and progenitor cells, originating from other tissues different than the muscle, are also able to follow a myogenic program. Participation of these cells in the repair process depends on their precise mobilisation to the site of the injury. RESULTS: In this study, we showed that stromal-derived factor-1 (Sdf-1) impacts on the mobilisation of CXC chemokine receptor (Cxcr)4-positive cells and improves skeletal muscle regeneration. Analysis of isolated and in vitro cultured satellite cells showed that Sdf-1 did not influence myoblasts proliferation and expression of myogenic regulatory transcription factors but induced migration of the myoblasts in Cxcr4-dependent ways. This phenomenon was also associated with the increased activity of crucial extracellular matrix modifiers, i.e. metalloproteases Mmp-2 and Mmp-9. CONCLUSIONS: Thus, positive impact of Sdf-1 on muscle regeneration is related to the mobilisation of endogenous cells, that is satellite cells and myoblasts, as well as non-muscle stem cells, expressing Cxcr4 and CD34.

Mouse gastrocnemius muscle regeneration after mechanical or cardiotoxin injury.

The goal of our study was to compare the skeletal muscle regeneration induced by two types of injury: either crushing, that causes muscle degeneration as a result of mechanical devastation of myofibers, or the injection of a cardiotoxin that is a myotoxic agent causing myolysis of myofibers leading to muscle degeneration. Regenerating muscles were analyzed at selected intervals, until the 14th day following the injury. We analyzed their weight and morphology. We also studied the expression of different myosin heavy chain isoforms as a molecular marker of the regeneration progress. Histological analysis revealed that inflammatory response and myotube formation in crushed muscles was delayed compared to cardiotoxin-injected ones. Moreover, the expression of myosin heavy chain isoforms was observed earlier in cardiotoxin-injured versus crushed muscles. We conclude that the dynamics of skeletal muscle regeneration depends on the method of injury.

Effect of pulmonary perfusion on the slopes of single-breath test of CO2.

The objective of this study was to evaluate the effects of lung perfusion on the slopes of phases II (S(II)) and III (S(III)) of a single-breath test of CO(2) (SBT-CO(2)). Fourteen patients submitted to cardiac surgery were studied during weaning from cardiopulmonary bypass (CPB). Pump flow was decreased in 20% steps, from 100% (total CPB = 2.5 l.min(-1).m(-2)) to 0%. This maneuver resulted in a progressive and opposite increase in pulmonary blood flow (PBF) while maintaining ventilator settings constant. SBT-CO(2), respiratory, and hemodynamic variables remained unchanged before and after CPB, reflecting a constant condition at those stages. S(III) was similar before and after CPB (19.6 +/- 2.8 and 18.7 +/- 2.1 mmHg/l, respectively). S(III) was lowest during 20% PBF (8.6 +/- 1.9 mmHg/l) and increased in proportion to PBF until exit from CPB (15.6 +/- 2.2 mmHg/l; P < 0.05). Similarly, S(II) and the CO(2) area under the curve increased from 163 +/- 41 mmHg/l and 4.7 +/- 0.6 ml, respectively, at 20% PBF to 313 +/- 32 mmHg/l and 7.9 +/- 0.6 ml (P < 0.05) at CPB end. When S(II) and S(III) were normalized by the mean percent expired CO(2), they remained unchanged during the protocol. In summary, the changes in PBF affect the slopes of the SBT-CO(2). Normalizing S(II) and S(III) eliminated the effect of changes in the magnitude of PBF on the shape of the SBT-CO(2) curve.

[Representation of physiologic functions in the modulation domain ]. / Representación de funciones fisiológicas en el Dominio de la Modulación.

The axes: amplitude, frequency, time, define a trihedral where the most usual representations occur in time domain (plane defined by the axes amplitude-time). The frequency of an action with respect to time is represented in the plane defined by the axes frequency-time in the so called "Modulation Domain", it is being considered very useful, expressive and easy to construct in the automatic treatment of signals.