Chromosomal aneuploidies are known for being the main cause of abnormal development of embryos with normal morphology, their implantation failure and early reproductive losses in IVF treatments. Preimplantation genetic screening (PGS) allows selecting embryos with normal chromosomal content and increases IVF treatment efficiency due to higher implantation rates and less frequent early pregnancy losses. New technologies used for PGS allow making genome-wide analysis of the presence of all chromosomes in embryos. This article presents our study of evaluation of two techniques used for PGS: previously developed and used in our laboratory a-CGH assay based on Agilent technology and newly tested semi-conductive NGS technique (Torrent technology).

Duchenne muscular dystrophy and Becker muscular dystrophy (DMD and BMD) are caused by mutations in the dystrophin gene (Xp21). In two-thirds of DMD/BMD cases, the mutation is a large deletion of one or several exons. We have established PGD for DMD/BMD using interphase fluorescence in situ hybridization (FISH) analysis on single nuclei from blastomeres for the detection of deletions of specific exons in the dystrophin gene. We performed PGD for two carrier females; one had a deletion of exons 45-50 (DMD), and the other had a deletion of exons 45-48 (BMD). An exon 45-specific probe was used in combination with probes for the X and Y centromeres. Using this straightforward approach, we can distinguish affected and unaffected male embryos as well as carrier female and normal female embryos. Three cycles were performed for each patient, which resulted in a pregnancy and the birth of a healthy girl. To the best of our knowledge, this approach for PGD has not been previously reported. The use of interphase FISH is an attractive alternative to sexing or PCR-based mutation detection for PGD patients with known deletions of the dystrophin gene.

Different cloud schemes are compared using the single column model (SCM) version of the general circulation model of the Canadian Centre for Climate Modelling and Analysis. Emphasis is placed on the differences between a statistical cloud scheme and an explicit one, two approaches commonly used in GCMs. The micro-physical processes are identical in both schemes so that the differences can be attributed to cloud formation and dissipation only. Two case studies are chosen, one for a day during the European Cloud and Radiation Experiment (EUCREX) and one for a day during the North Atlantic Regional Experiment (NARE). During the EUCREX case study the SCM is forced by advection from the mesoscale model GESIMA (Geesthacht Simulation Model of the Atmosphere). The comparison of ice water content as a function of height shows that the SCM cannot reproduce the observed nearly linear decrease with height as well as GESIMA does above 8.5 km. If temperature, specific humidity: and cloud ice advection are used to force the SCM, the explicit scheme simulates a coherent thick cirrus cloud, which is in better agreement with observations than the separate cloud layers simulated with the statistical scheme. Sensitivity studies show that cloud ice advection is crucial for the formation of the cirrus deck in this case study, but omitting specific humidity advection improves the agreement with observations. During the NARE case study four sequential vertical profiles are available so that wind, temperature, and moisture of the SCM can be nudged toward their observed values. The observed lifting of the boundary layer cloud with time is captured best by the statistical scheme when adjusted toward observations with a relaxation timescale of one hour or less.

Models of the radiative transport through clouds in most applications use the assumption of horizontally plane-parallel and homogeneous clouds. In fact, as shown for example by this study, real clouds are not homogeneous. They possess strong vertical and horizontal inhomogeneities. This feature is demonstrated with in-situ data from Arctic stratus clouds and midlatitude cirrus clouds. In cirrus clouds, not only variations of bulk quantities such as number density or ice water content are observed but also those of particle size distributions on a horizontal scale of a few hundred meters. Such inhomogeneities of size spectra are also found in simulations with a mesoscale model when cloud microphysical processes are considered in great detail. Furthermore, this paper discusses the different results on cloud structures which would be observed by ground-based or space-borne radar and lidar. The backscatter intensity is calculated from the measured in-situ data, showing that cloud inhomogeneities cannot be neglected for the interpretation of remote sensing data.

A new scheme for simulating clouds, which considers subgrid temperature and humidity fluctuations, is proposed. This is done by using local estimates of first and second moments of the joint specific humidity–potential temperature-distribution in a Monte-Carlo-integration of the relevant processes. Simulation of cirrus and low level cloudiness has been done within the frame of EUCREX (European Cloud and Radiation Experiment). With the new scheme, a part of the given grid volume can be supersaturated and condensation or ice formation occurs without a supersaturation of the entire volume to be realized. This produces more frequent and earlier cloud water (ql) and cloud ice (qi) and results in an increase in time-average cloud activity. The domain averaged values ql and qi using the new scheme remain larger most of the time and are appreciable after the time they are approximately zero when no subgrid fluctuations are considered. The assumption that local condensation can occur in the presence of turbulent fluctuations, even though the average state is below saturation, is part of a general effort to improve sub-scale cloud modeling. It appears to be necessary for a model which uses a larger grid volume and therefore needs more accurate predictions for the subgrid turbulence.

In this study the formation of a contrail from an aircraft flying near the tropopause is simulated using a three-dimensional mesoscale atmospheric model including a very complex scheme of parameterized cloud microphysical processes. The model predicted ice concentrations are in very good agreement with data measured during the International Cirrus Experiment (ICE), 1989. Sensitivity simulations were run to determine humidity forcing on the life time of contrails.

The physical parameterizations implemented in the reference version of the non-hydrostatic mesoscale model GESIMA (=Geesthacht Simulation Model of the Atmosphere) are presented and discussed, namely the turbulent diffusion, the cloud physics, the radiative transfer, and the lower boundary treatment (energy budget). Three different applications show satisfactory agreement with either measurements or physical reasoning

Different ice nucleation algorithms are implemented in a cloud microphysical scheme and numerical simulations of clouds are performed using a three-dimensional mesoscale model. The predicted ice crystal fields are found to be sensitive to the different modes of calculation of the number of deposition/condensation freezing nuclei and contact freezing nuclei. Also a time and supercooling dependence of this sensitivity is established.The general features of the cirrus clouds observed by the research aircraft Falcon during the 1989 ICE (International Cirrus Experiment) mission ICE212 are compared to those of the cirrus clouds generated by the model. The cloud top height, the cloud ice content and the ice number concentrations seem to be reproduced well.

In this study, the formation of a contrail from an aircraft flying near the tropopause is simulated using a three-dimensional mesoscale atmospheric model including a very complex scheme of parameterized cloud microphysical processes. Two different primary ice nucleation parameterizations for deposition nucleation, condensation freezing, and contact freezing are applied. The model-predicted ice concentrations are compared to data measured during the International Cirrus Experiment (ICE), 1989.

Recently available algorithms describing (parameterizing) the cloud microphysics are combined and implemented in the three dimensional non-hydrostatic mesoscale model GESIMA (GEesthachter SImulationsModell der Atmosphare). All three water phases are taken into account. Clouds are represented by two groups of prognostic equations describing the changes in cloud mass and particle number concentration. The radiation scheme uses the mass and the particle number concentration to compute the optical cloud properties

A three-dimensional mesoscale model with parameterized microphysics of clouds and precipitation has been extended to include wet scavenging and deposition of trace metals from the atmosphere. As a sample case the wet removal of atmospheric lead has been chosen. Simulations were carried out in a domain of 200 × 200 km2 in the southeastern part of the North Sea including many clouds in various stages of development. The basic assumption is that the particles acting as host for the lead particles are cloud condensation nuclei (CCN) calculated in the model as part of aerosol particles in the air. The variation of the average concentration of aerosol particles with height as a function of size is based on data given in Pruppacher and Klett (1978, Microphysics of Clouds and Precipitation, Reidel, Dordrecht). Both calculated (long range transport model) and measured atmospheric monthly mean concentration of lead at the German coast of North Sea and Baltic Sea given by Petersen et al. (1989, NATO) and Stöβel (1987, Ext. Rep. GKSS 87/E/34) are used as an input pollution level by calculation of the vertical profile of the initial mean mass lead concentration in the air. The lead is assumed to be distributed uniformly on the aerosol particles, and the vertical profile of the initial mass concentration of lead in the air is assumed to be proportional to the vertical profile of number of aerosol particles as a function of size with height. In other words, in the model we deal with that fraction of lead, which can enter cloud water mainly through nucleation scavenging (in-cloud scavenging, ‘rainout’).

Levkov, L., Jacob, D., Eppel, D. and Grassl, H., 1989. Test of a parametrization scheme for cloud microphysical processes in a 3-D mesoscale model. Atmos. Res., 24: 193-208. A parametrization scheme for the simulation of ice in clouds is incorporated into the hydrostatic version of the FZG (Forschungszentrum Geesthacht) three-dimensional mesoscale model. Numerical simulations of precipitation are performed for observed meteorological conditions over the North Sea. Major features of convective structures have been simulated. Also a scheme for cloud aerosol interaction has been developed, however, it could not be compared to measurements due to the lack of observed aerosol parameters.