414 research outputs found
Working time accounts and firm performance in Germany
This study investigates whether working time accounts affect the performance of German establishments based on the Establishment Panel from the Institute for Employment Research. The major results are: productivity and investments are positively correlated with working time accounts. No significant effects of working time accounts can be detected on wages and on operating surplus. On average, we find a tendency towards negative effects on profits. This result is less likely in phases of low product demand and for export-oriented, large establishments with a high share of skilled workers. Under strong sales fluctuations, we find positively significant effects on the operating surplus. JEL: C22, D21, J21, J22, J2
Der Bruch der Theorie in der Praxis durch Not
Some Remarks on Lujo Brentano's View of Labor Market Problems
Lujo Brentano (1844-1931) aimed for "realism" in economics. Regarding labor market theory, two topics are of particular interest: His investigations on "Hours and Wages in Relation to Production" (Scribner's 1894) and his analysis "On the History and Development of Gilds and the Origins of Trade Unions" (Trubner 1870). The topics of are discussed with a view on recent developments in labor economics.Lujo Brentano (1844-1931) hat sich als "realistischen" Ökonomen verstanden. Im Bereich der Arbeitsmarkttheorie sind zwei Bereiche von besonderem Interesse: Seine Untersuchungen über den Zusammenhang zwischen Lohn, Arbeitszeit und Arbeitsleistung und seine Überlegungen zur Bildung von kollektiven Formen der Lohnsetzung. Diese beiden Themen werden unter Einbeziehung gesamtwirtschaftlicher und methodischer Aspekte und einiger moderner Gesichtspunkte diskutiert
Reassessing the Impact of High Performance Workplaces
High performance workplace practices were extolled as an efficient means to increase firm productivity. The empirical evidence is disputed, however. To assess the productivity effects of a broad variety of measures, we simultaneously account for both unobserved heterogeneity and endogeneity using establishment panel data for Germany. We show that increasing employee participation enhances firm productivity in Germany, whereas incentive systems do not foster productivity. Our results further indicate that firms with structural productivity problems tend to introduce organisational changes that increase employee participation whereas well performing firms are more likely to offer incentives
Optogenetic control of Drosophila using a red-shifted channelrhodopsin reveals experience-dependent influences on courtship
Optogenetics allows the manipulation of neural activity in freely moving animals with millisecond precision, but its application in Drosophila melanogaster has been limited. Here we show that a recently described red activatable channelrhodopsin (ReaChR) permits control of complex behavior in freely moving adult flies, at wavelengths that are not thought to interfere with normal visual function. This tool affords the opportunity to control neural activity over a broad dynamic range of stimulation intensities. Using time-resolved activation, we show that the neural control of male courtship song can be separated into (i) probabilistic, persistent and (ii) deterministic, command-like components. The former, but not the latter, neurons are subject to functional modulation by social experience, which supports the idea that they constitute a locus of state-dependent influence. This separation is not evident using thermogenetic tools, a result underscoring the importance of temporally precise control of neuronal activation in the functional dissection of neural circuits in Drosophila
Oral particle uptake and organ targeting drives the activity of amphotericin B nanoparticles
There are very few drug delivery
systems that target key organs
via the oral route, as oral delivery advances normally address gastrointestinal
drug dissolution, permeation, and stability. Here we introduce a nanomedicine
in which nanoparticles, while also protecting the drug from gastric
degradation, are taken up by the gastrointestinal epithelia and transported
to the lung, liver, and spleen, thus selectively enhancing drug bioavailability
in these target organs and diminishing kidney exposure (relevant to
nephrotoxic drugs). Our work demonstrates, for the first time, that
oral particle uptake and translocation to specific organs may be used
to achieve a beneficial therapeutic response. We have illustrated
this using amphotericin B, a nephrotoxic drug encapsulated within <i>N</i>-palmitoyl-<i>N</i>-methyl-<i>N</i>,<i>N</i>-dimethyl-<i>N</i>,<i>N</i>,<i>N</i>-trimethyl-6-<i>O</i>-glycol chitosan
(GCPQ) nanoparticles, and have evidenced our approach in three separate
disease states (visceral leishmaniasis, candidiasis, and aspergillosis)
using industry standard models of the disease in small animals. The
oral bioavailability of AmB-GCPQ nanoparticles is 24%. In all disease
models, AmB-GCPQ nanoparticles show comparable efficacy to parenteral
liposomal AmB (AmBisome). Our work thus paves the way for others to
use nanoparticles to achieve a specific targeted delivery of drug
to key organs via the oral route. This is especially important for
drugs with a narrow therapeutic index
A new body mass estimation of <i>Brachiosaurus brancai</i> Janensch, 1914 mounted and exhibited at the Museum of Natural History (Berlin, Germany)
A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (me/cfs) and sickness behavior
It is of importance whether myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a variant of sickness behavior. The latter is induced by acute infections/injury being principally mediated through proinflammatory cytokines. Sickness is a beneficial behavioral response that serves to enhance recovery, conserves energy and plays a role in the resolution of inflammation. There are behavioral/symptomatic similarities (for example, fatigue, malaise, hyperalgesia) and dissimilarities (gastrointestinal symptoms, anorexia and weight loss) between sickness and ME/CFS. While sickness is an adaptive response induced by proinflammatory cytokines, ME/CFS is a chronic, disabling disorder, where the pathophysiology is related to activation of immunoinflammatory and oxidative pathways and autoimmune responses. While sickness behavior is a state of energy conservation, which plays a role in combating pathogens, ME/CFS is a chronic disease underpinned by a state of energy depletion. While sickness is an acute response to infection/injury, the trigger factors in ME/CFS are less well defined and encompass acute and chronic infections, as well as inflammatory or autoimmune diseases. It is concluded that sickness behavior and ME/CFS are two different conditions
Translational toxicology in setting occupational exposure limits for dusts and hazard classification – a critical evaluation of a recent approach to translate dust overload findings from rats to humans
Background
We analyze the scientific basis and methodology used by the German MAK Commission in their recommendations for exposure limits and carcinogen classification of “granular biopersistent particles without known specific toxicity” (GBS). These recommendations are under review at the European Union level. We examine the scientific assumptions in an attempt to reproduce the results. MAK’s human equivalent concentrations (HECs) are based on a particle mass and on a volumetric model in which results from rat inhalation studies are translated to derive occupational exposure limits (OELs) and a carcinogen classification.
Methods
We followed the methods as proposed by the MAK Commission and Pauluhn 2011. We also examined key assumptions in the metrics, such as surface area of the human lung, deposition fractions of inhaled dusts, human clearance rates; and risk of lung cancer among workers, presumed to have some potential for lung overload, the physiological condition in rats associated with an increase in lung cancer risk.
Results
The MAK recommendations on exposure limits for GBS have numerous incorrect assumptions that adversely affect the final results. The procedures to derive the respirable occupational exposure limit (OEL) could not be reproduced, a finding raising considerable scientific uncertainty about the reliability of the recommendations. Moreover, the scientific basis of using the rat model is confounded by the fact that rats and humans show different cellular responses to inhaled particles as demonstrated by bronchoalveolar lavage (BAL) studies in both species.
Conclusion
Classifying all GBS as carcinogenic to humans based on rat inhalation studies in which lung overload leads to chronic inflammation and cancer is inappropriate. Studies of workers, who have been exposed to relevant levels of dust, have not indicated an increase in lung cancer risk. Using the methods proposed by the MAK, we were unable to reproduce the OEL for GBS recommended by the Commission, but identified substantial errors in the models. Considerable shortcomings in the use of lung surface area, clearance rates, deposition fractions; as well as using the mass and volumetric metrics as opposed to the particle surface area metric limit the scientific reliability of the proposed GBS OEL and carcinogen classification.International Carbon Black Associatio
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