The Slowdown in Labour Productivity in the 1990s: The Impact of The Employment Policies

Labour productivity fell in France in the early 1990s. The annual growth rate in productivity per employee in the non-agricultural market sector fell from 2% per year over the 1982-1992 period to 0.7% over the 1993-2002 period. The drop in labour productivity gains in France is analysed here based on quarterly macroeconomic data for the non-agricultural market sector. An employment equation is estimated. A number of variables can explain this drop: the change in working hours, the cost of labour and the relative cost of inputs capital and skilled and unskilled labour and the proportion of part-time workers in employment. The shorter working week and reduction in the relative cost of unskilled labour compared with skilled labour both contributed to the downturn in labour productivity gains, which were probably accompanied by a slowdown in underlying productivity.Labor Productivity, Employment, Unskilled Workers and Skilled Workers, Cointegration

Excitable waves at the margin of the contact area between a cell and a substrate.

International audienceIn this paper, we study a new physical mechanism to generate an activator field which signals the extreme margin of the contact area between an adherent cell and the substrate. This mechanism is based on the coupling between the adhesive bridges connecting the substrate to the cytoskeleton and a cytosolic activator. Once activated by adhesion on the adhesive bridges, this activator is free to diffuse on the membrane. We propose that this activator is part of the mecano-transduction pathway which links adhesion to actin polymerization and, thus, to cellular motility. The consequences of our model are as follows: (a) the activator is localized at the rim of the contact area, (b) the adhesion is reinforced at the margin of the contact area between the cell and the substrate, (c) excitable waves of the activator can propagate along the adhesion rim

Parametric identification of elastic-plastic constitutive laws using spherical indentation

In this paper we present a methodology to characterize elastic-plastic constitutive law of metallic materials using spherical indentation tests and parametric identification coupled with finite elements model simulation. This procedure was applied to identify aluminium, copper and titanium mechanical properties and the identified models show difference that do not exceed 10% with experimental uniaxial tensile tests results. A sensitivity study according to a 2^k Design of Experience (DoE) was achieved to determine which data that can be extracted from pile-up is the most relevant to use in order to enhance the identification procedure. It appears that the maximum pile-up height seems to be the best suited for this purpose

Actin machinery and mechanosensitivity in invadopodia, podosomes and focal adhesions.

International audienceThe invasiveness of cells is correlated with the presence of dynamic actin-rich membrane structures called invadopodia, which are membrane protrusions that are associated with localized polymerization of sub-membrane actin filaments. Similar to focal adhesions and podosomes, invadopodia are cell-matrix adhesion sites. Indeed, invadopodia share several features with podosomes, but whether they are distinct structures is still a matter of debate. Invadopodia are built upon an N-WASP-dependent branched actin network, and the Rho GTPase Cdc42 is involved in inducing invadopodial-membrane protrusion, which is mediated by actin filaments that are organized in bundles to form an actin core. Actin-core formation is thought to be an early step in invadopodium assembly, and the actin core is perpendicular to the extracellular matrix and the plasma membrane; this contrasts with the tangential orientation of actin stress fibers anchored to focal adhesions. In this Commentary, we attempt to summarize recent insights into the actin dynamics of invadopodia and podosomes, and the forces that are transmitted through these invasive structures. Although the mechanisms underlying force-dependent regulation of invadopodia and podosomes are largely unknown compared with those of focal adhesions, these structures do exhibit mechanosensitivity. Actin dynamics and associated forces might be key elements in discriminating between invadopodia, podosomes and focal adhesions. Targeting actin-regulatory molecules that specifically promote invadopodium formation is an attractive strategy against cancer-cell invasion

Alvo hemodinâmico: uma ferramenta visual de terapia "goal-directed" para pacientes sépticos

OBJECTIVE: To improve understanding of the hemodynamic status of patients with sepsis by nursing teams through the attainment of hemodynamic parameters using a pentaxial "target" diagram as a clinical tool. Parameters include cardiac index (CI), arterial oxygen saturation (SaO2), mean arterial pressure (MAP), arterial blood lactate, and central venous oxygen saturation (ScvO2). METHODS: Design: Prospective descriptive study. Setting: The intensive care unit of a university hospital. Patients: During a 6-month period, 38 intubated septic shock patients were included in the study. Survivors and nonsurvivors were compared. Interventions: MAP, CI, SaO2, ScvO2 and lactate were measured at 0, 6, 12, 24, 36, and 48 h. Measurements were recorded on the target diagram along with the norepinephrine infusion rate and the hemoglobin (Hb) level. The number of lactate and ScvO2 measurements achieved during the target period were compared to a 6-month retrospective control period just before starting the protocol. We assessed the nurse knowledge status prior to the introduction of target diagram. We then performed a post-test after implementing the new recording technique. MEASUREMENTS AND RESULTS: The nursing team expressed a positive attitude toward the target concept. The mean number of lactate and ScvO2 measurements performed for each patient during the control period was significantly lower than during the target period, and those values were rarely used as goal values before the introduction of the target diagram. At 24 hours, 46% of the survivors had achieved all the goal parameter values of the target diagram, compared to only 10% of nonsurvivors (P = .01). CONCLUSION: The target diagram is a visual multiparametric tool involving all the medical and nursing team that helps achieve goal-directed therapy for septic patients. The number of goal values reached at each time point during the first 48 hours was closely linked to mortality.OBJETIVO: Melhorar a compreensão do "status" hemodinâmico de pacientes em sepse pelas equipes de enfermagem através da obtenção de parâmetros hemodinâmicos usando um diagrama-alvo pentaxial como ferramenta clínica. Os parâmetros usados foram índice cardíaco, saturação arterial de oxigênio, pressão arterial media, lactato sangüíneo arterial e saturação venosa central de oxigênio. MÉTODOS: Estudo descritivo prospectivo, realizado na Unidade de Terapia Intensiva de um Hospital Universitário. Pacientes: Durante um período de 6 meses, 38 pacientes intubados em choque séptico foram incluídos no estudo. Foram comparados sobreviventes vs. não sobreviventes. Intervenções: Os cinco parâmetros referidos foram medidos nas horas 0, 6, 12, 24, 36 e 48. As medidas foram registradas no diagrama alvo, juntamente com a velocidade de infusão de norepinefrina e nível de hemoglobina. O número de medidas de lactato e saturação venosa central de oxigênio realizado durante o período de estudo foi comparado com um período retrospectivo de 6 meses imediatamente precedendo a introdução do protocolo. Avaliamos o nível de conhecimento das equipes de enfermagem antes da introdução do diagrama-alvo. Após a realização do protocolo realizamos uma nova avaliação. MEDIDAS E RESULTADOS: A equipe de enfermagem exprimiu uma atitude positiva em relação ao conceito de diagrama alvo. O número de medidas de lactato e saturação venosa central de oxigênio foi significativamente menor durante o período controle anterior ao protocolo. E os valores medidos raramente foram empregados como valores meta antes da introdução do diagrama-alvo. Na medida de 24 horas, 46% dos sobreviventes haviam atingido todas as metas do diagrama-alvo, contra apenas 10% dos não sobreviventes (P = 0,01). CONCLUSÃO. O diagrama-alvo é uma ferramenta visual multiparamétrica envolvendo, as equipes médicas e de enfermagem, que auxilia a obtenção de uma estratégia terapêutica para pacientes sépticos. O número de valores meta atingidos a cada momento durante as primeiras 48 horas relaciona-se à mortalidade

Validation of mechanical damage monitoring on aluminium freestanding thin films using electrical measurements

This paper describes a new technique allowing the monitoring of damage in metallic freestanding thin films during micro-tensile test by using electrical characterization. After a presentation of the set-up, results obtained on aluminium thin coatings by using two calculation methods for damage variable are presented and commented

PeroxisomeDB: a database for the peroxisomal proteome, functional genomics and disease

Peroxisomes are essential organelles of eukaryotic origin, ubiquitously distributed in cells and organisms, playing key roles in lipid and antioxidant metabolism. Loss or malfunction of peroxisomes causes more than 20 fatal inherited conditions. We have created a peroxisomal database () that includes the complete peroxisomal proteome of Homo sapiens and Saccharomyces cerevisiae, by gathering, updating and integrating the available genetic and functional information on peroxisomal genes. PeroxisomeDB is structured in interrelated sections ‘Genes’, ‘Functions’, ‘Metabolic pathways’ and ‘Diseases’, that include hyperlinks to selected features of NCBI, ENSEMBL and UCSC databases. We have designed graphical depictions of the main peroxisomal metabolic routes and have included updated flow charts for diagnosis. Precomputed BLAST, PSI-BLAST, multiple sequence alignment (MUSCLE) and phylogenetic trees are provided to assist in direct multispecies comparison to study evolutionary conserved functions and pathways. Highlights of the PeroxisomeDB include new tools developed for facilitating (i) identification of novel peroxisomal proteins, by means of identifying proteins carrying peroxisome targeting signal (PTS) motifs, (ii) detection of peroxisomes in silico, particularly useful for screening the deluge of newly sequenced genomes. PeroxisomeDB should contribute to the systematic characterization of the peroxisomal proteome and facilitate system biology approaches on the organelle