A dynamic heterogeneous labour demand model for German manufacturing

This paper presents an application of the Generalised Error Correction Model (GECM) for heterogeneous factor demands based on the quadratic cost function. Using data for 26 West German manufacturing industries over the period 1976-1995, it turns out that less general specifications such as the partial adjustment and the static AR(1) model are rejected. Furthermore, both shortrun and long-run labour demands of different skill classes are inelastic. Unskilled labour is found to have a somewhat higher wage elasticity in absolute terms than medium-skilled labour. A small part of shift in demand away from unskilled labour can be explained by the substitutability relationship between intermediate materials and unskilled labour. Between 6 and 13 percent of the observed shift towards high-skilled labour can be explained by capital accumulation. --heterogeneous labour demand,dynamics,price elasticities

The Demand of Heterogeneous Labour in Germany

In this paper, four commonly provided explanations for the shift in labour demand for different skill groups are investigated: the substitutability of inputs; the own-price sensitivity for different types of labour; the effect of economic growth and the impact of technological change. In general, the shift of demand away from unskilled labour can be explained by the large own-price elasticity of unskilled labour and by biased technological change. During the period of 19771994, the rate of biased technological progress against unskilled workers seems to be as large in the traded as in the non-traded goods industries. Furthermore, in three out of five sectors considered, technological change is biased towards high-skilled labour. --technological change,heterogeneous labour

Curvature conditions and substitution pattern among capital, energy, materials and heterogeneous labour

This study deals with the determinants of factor demand in 27 industries of the manufacturing sector during the period 1978 to 1990. Using a quadratic cost function, six production factors are distinguished : capital, energy, three types of labour and intermediate materials. A parametric test of the concavity of the cost function in prices is provided and price elasticities are compared when curvature conditions are imposed or not. The result show, firstly, that in general estimates do not appear very sensitive to imposing theoretical restrictions implied by optimising behaviour. Secondly, demand for unskilled and medium skilled labour than any other pairs of inputs. --curvature conditions,elasticities of substitution,skill structure

Outsourcing of services, imported materials and the demand for heterogeneous labour : an application of a generalised box-cox function

This paper examines the effects that purchased services and imported intermediate materials have on the labour demand for different skills in the manufacturing sector. We derive and estimate a factor demand system based on the generalised Box-Cox cost function nesting both the normalised quadratic and the translog functional form. We find that the impacts of output and capital growth are more important in explaining the demand for heterogeneous labour than substitution effects between labour and non-labour inputs. Similarly, the increasing use of both imported materials and purchased services is rather a consequence of output growth than input substitution. --Outsourcing of services,intermediate imports,heterogeneous labour,Box-Cox cost function

Imposing and testing curvature conditions on a Box-Cox function

We present a new method for imposing and testing concavity of a cost function using asymptotic least squares, which can easily be implemented even for cost functions which are nonlinear in parameters. We provide an illustration on the basis of a (generalized) Box-Cox cost function with six inputs: capital, labor disaggregated in three skill levels, energy, and intermediate materials. A parametric test of the concavity of the cost function in prices is presented, and price elasticities are compared when curvature conditions are imposed and when they are not. The results show that, although concavity is statistically rejected, the estimates are not very sensitive to its imposition. We find that substitution is stronger between the different types of labor than between any other pair of inputs. --input demands,concavity,inequality restrictions,Box-Cox

Development of an Efficient Genome Editing Method by CRISPR/Cas9 in a Fish Cell Line

This project was carried out during CD’s BBSRC Eastbio PIPS placement at Marine Scotland. The authors are grateful to Dr Milena Monte (University of Aberdeen) for help with the FACS analysis. The authors wish to thank Dr Filippo Del Bene (Neuronal Circuit Development, Institut Curie) and Dr Wenbiao Chen (School of Medicine, Vanderbilt University) for the Addgene plasmids, #61051 and #47929, respectively, and Prof. Nancy C. Reich Marshall (Department of Molecular Genetics and Microbiology, Stony Brooks University) for the plasmid pmEGFP-N1.Peer reviewedPublisher PD

fMRI visualization of transient activations in the rat olfactory bulb using short odor stimulations

International audienceOdor-evoked activity in the olfactory bulb displays both spatial and temporal organization. The difficulty when assessing spatio-temporal dynamics of olfactory representation is to find a method that reconciles the appropriate resolution for both dimensions. Imaging methods based on optical recordings can reach high temporal and spatial resolution but are limited to the observation of the accessible dorsal surface. Functional magnetic resonance imaging (fMRI) may be useful to overcome this limitation as it allows recording from the whole brain. In this study, we combined ultra fast imaging sequence and short stimulus duration to improve temporal resolution of odor-evoked BOLD responses. Short odor stimulations evoked high amplitude BOLD responses and patterns of activation were similar to those obtained in previous studies using longer stimulations. Moreover, short odor exposures prevented habituation processes. Analysis of the BOLD signal time course in the different areas of activation revealed that odorant response maps are not static entities but rather are temporally dynamic as reported by recent studies using optical imaging. These data demonstrated that fMRI is a non-invasive method which could represent a powerful tool to study not only the spatial dimension of odor representation but also the temporal dimension of information processing

Causal impact analysis for app releases in google play

App developers would like to understand the impact of their own and their competitors' software releases. To address this we introduce Causal Impact Release Analysis for app stores, and our tool, CIRA, that implements this analysis. We mined 38,858 popular Google Play apps, over a period of 12 months. For these apps, we identified 26,339 releases for which there was adequate prior and posterior time series data to facilitate causal impact analysis. We found that 33% of these releases caused a statistically significant change in user ratings. We use our approach to reveal important characteristics that distinguish causal significance in Google Play. To explore the actionability of causal impact analysis, we elicited the opinions of app developers: 56 companies responded, 78% concurred with the causal assessment, of which 33% claimed that their company would consider changing its app release strategy as a result of our findings

The validity and reliability of a novel indoor player tracking system for use within wheelchair court sports

The aim of the current study was to investigate the validity and reliability of a radio- frequency based system for accurately tracking athlete movement within the wheelchair court sports. Four wheelchair specific tests were devised to assess the system during i) static measurements ii) incremental fixed speeds iii) peak speeds, and iv) multi-directional movements. During each test, three sampling frequencies (4, 8 & 16 Hz) were compared to a criterion method for distance, mean and peak speeds. Absolute static error remained between 0.19-0.32 m across the session. Distance values (test ii) showed greatest relative error in 4 Hz tags (1.3%), with significantly lower errors seen in higher frequency tags (< 1.0%). Relative peak speed errors of < 2.0% (test iii) were revealed across all sampling frequencies in relation to the criterion (4.00 ± 0.09 m·sˉ¹). Results showed 8 and 16 Hz sampling frequencies displayed the closest to criterion values, whilst intra-tag reliability never exceeded 2.0% coefficient of variation (% CV) during peak speed detection. Minimal relative distance errors (< 0.2%) were also seen across sampling frequencies (test iv). To conclude, the indoor tracking system is deemed an acceptable tool for tracking wheelchair court match-play using a tag frequency of 8 or 16 Hz

Exact, E=0, Solutions for General Power-Law Potentials. I. Classical Orbits

For zero energy, $E=0$, we derive exact, classical solutions for {\em all} power-law potentials, $V(r)=-\gamma/r^\nu$, with $\gamma>0$ and $-\infty <\nu<\infty$. When the angular momentum is non-zero, these solutions lead to the orbits $\r(t)= [\cos \mu (\th(t)-\th_0(t))]^{1/\mu}$, for all $\mu \equiv \nu/2-1 \ne 0$. When $\nu>2$, the orbits are bound and go through the origin. This leads to discrete discontinuities in the functional dependence of $\th(t)$ and $\th_0(t)$, as functions of $t$, as the orbits pass through the origin. We describe a procedure to connect different analytic solutions for successive orbits at the origin. We calculate the periods and precessions of these bound orbits, and graph a number of specific examples. Also, we explain why they all must violate the virial theorem. The unbound orbits are also discussed in detail. This includes the unusual orbits which have finite travel times to infinity and also the special $\nu = 2$ case.Comment: LaTeX, 27 pages with 12 figures available from the authors or can be generated from Mathematica instructions at end of the fil