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The wetting of soft polymer substrates brings in multiple complexities when compared with the wetting on rigid substrates. The contact angle of the liquid is no longer governed by Young’s Law, but is affected by the substrate’s bulk and surface deformations. On top of that, elastic interfaces exhibit a surface energy that depends on how much they are stretched—a feature known as the Shuttleworth effect (or as surface-elasticity). Here, we present two models through which we explore the wetting of drops in the presence of a strong Shuttleworth effect. The first model is macroscopic in character and consistently accounts for large deformations via a neo-Hookean elasticity. The second model is based on a mesoscopic description of wetting, using a reduced description of the substrate’s elasticity. While the second model is more empirical in terms of the elasticity, it enables a gradient dynamics formulation for soft wetting dynamics. We provide a detailed comparison between the equilibrium states predicted by the two models, from which we deduce robust features of soft wetting in the presence of a strong Shuttleworth effect. Specifically, we show that the (a)symmetry of the Shuttleworth effect between the ‘dry’ and ‘wet’ states governs horizontal deformations in the substrate. Our results are discussed in the light of recent experiments on the wettability of stretched substrates.

To facilitate the analysis of pattern formation and the related phase transitions in Bose–Einstein condensates, we present an explicit approximate mapping from the nonlocal Gross–Pitaevskii equation with cubic nonlinearity to a phase field crystal (PFC) model. This approximation is valid close to the superfluid–supersolid phase transition boundary. The simplified PFC model permits the exploration of bifurcations and phase transitions via numerical path continuation employing standard software. While revealing the detailed structure of the bifurcations present in the system, we demonstrate the existence of localized states in the PFC approximation. Finally, we discuss how higher-order nonlinearities change the structure of the bifurcation diagram representing the transitions found in the system.

In this work we describe an alternative strategy for the development of heat assisted magnetic recording (HAMR) media. In our approach the need for a storage material with a temperature dependent anisotropy and to provide a read out signal is separated so that each function can be optimised independently. This is achieved by the use of an exchange bias structure where a conventional CoCrPt-SiO2 recording layer is exchange biased to an underlayer of IrMn such that heating and cooling in the exchange field from the recording layer results in a shifted loop. This strategy requires the reorientation of the IrMn layer to allow coupling to the recording layer. This has been achieved by the use of an ultrathin (0.8nm) layer of Co deposited beneath the IrMn layer. In this system the information is in effect stored in the antiferromagnetic (AF) layer and hence there is no demagnetising field generated by the stored bits. A loop shift of 688 Oe has been achieved where both values of coercivity lie to one side of the origin and the information cannot be erased by a magnetic field.

Recently a novel media structure for thermally assisted magnetic recording was proposed consisting of a layer of FePt exchange coupled to a FeRh layer. The FePt forms a high magnetocrystalline anisotropy, high coercivity ferromagnetic layer. The FeRh layer is antiferromagnetic at room temperature, but upon heating above a transition temperature becomes ferromagnetic with a large magnetic moment and low magnetocrystalline anisotropy. The coupled ferromagnetic FePt and FeRh layers form an exchange-spring system significantly lowering the coercive field of the composite system compared to a single layer of FePt. This feature opens intriguing possibilities for media applications for thermally assisted magnetic recording where the ferromagnetic phase of FeRh is exploited to help write the media while the low-temperature antiferromagnetic phase supports the long-term stability. Here temperature-dependent structural and magnetic measurements of undoped and doped FeRh single layer and FePt-FeRh bilayer films are presented and the promises and challenges of the exchange spring media structure are discussed.

GRB 021004 is one of the best sampled gamma-ray bursts (GRB) to date, although the nature of its light curve is still being debated. Here we present a large amount (107) of new optical, near-infrared (NIR) and millimetre observations, ranging from 2 hours to more than a year after the burst. Fitting the multiband data to a model based on multiple energy injections suggests that at least 7 refreshed shocks took place during the evolution of the afterglow, implying a total energy release (collimated within an angle of 1.8 deg) of ~ 8x10^51 erg. Analysis of the late photometry reveals that the GRB 021004 host is a low extinction (Av ~ 0.1) starburst galaxy with M_B ~ -22.0., 9 pages, 5 figures, accepted for publication in A&Ax

Amorphous hydrogenated carbon films were prepared by ion beam deposition. The degree of sp3 coordination and the density of the films were determined from ultraviolet photoelectron valence band spectra and electron energy loss spectra. The films prepared can be described as highly sp3 coordinated (about 80%) and of relatively high density (about 2.3 g/cm3). An indication of a negative electron affinity is found in the valence band spectra. In an attempt to lower the work function, lithium-containing a-C:H films were deposited by lithium evaporation from dispensers during deposition of the a-C:H films. Photoelectron spectra of these films reveal parallel shifts of the core levels and valence band to higher binding energies with respect to the spectra of pure amorphous hydrogenated carbon. These shifts can be attributed to a shift of the Fermi level due to a charge transfer from the lithium to the carbon matrix. From the onset of the valence band spectra at low kinetic energy and from total photoyield spect...

Undoped and doped tetrahedrally bonded amorphous carbon films (ta-C) were grown in UHV by alternating deposition of low energy mass separated 12 C + ions and dopant ions. For undoped ta-C the fraction of sp 3 -bonded carbon atoms was determined by EELS as a function of ion energy. The observed energy dependence is compared to data from vacuum arc-deposited ta-C and to existing nucleation models. With XPS and UPS measurements, the valence band structure and the chemical bonding of B- and N-doped as well as undoped ta-C films was characterized.

Lithium-containing amorphous hydrogenated carbon coatings (a-C:HLi) have been prepared by a modified plasma assisted chemical vapor deposition (rf-PACVD) technique. In order to investigate the interaction of energetic oxygen with these films they were irradiated with oxygen ions of 3 keV energy. Erosion and retention behavior was measured by direct detection of emitted particles using a differentially pumped line-of-sight quadrupole mass spectrometer. Results are compared to those of previous studies on pure and boron-containing carbon materials. Like in these materials, emission of reaction products from a-C:HLi is dominated by CO and CO2, to a smaller extent also emission of lithium oxide, Li2O, is observed. As compared to pure carbon the emission of reaction products is delayed, and the erosion yield after oxygen saturation of the surface layer is lower for lithium-containing films. Taking into account results of X-ray photoelectron spectroscopy, it can be concluded that the interaction of a-C:HLi with energetic oxygen follows the same general trends as observed for boron-containing carbon materials. However, chemical reactions and their dependence on conditions of irradiation are more complex in a-C:HLi than in boron-containing carbon.

Pure and Li-containing amorphous hydrogenated carbon films were deposited using an ion beam deposition technique. Depending on Li content and deposition conditions, differences in chemical structure are detected. Samples were irradiated at room temperature with energetic oxygen ions of 100 eV to 1 keV. Transient time during which layers retain oxygen is significantly longer for Li-containing as compared to pure amorphous hydrogenated carbon films. Oxygen uptake is found to be mainly determined by Li content. For lower contents (cLi 50 at.%) carbon is almost completely removed upon irradiation and the resulting composition of the films is found to be close to the stochiometry of Li oxide.

Amorphous hydrogenated carbon films (a-C: H) were deposited in a capacitively coupled r.f. discharge reactor. The precursor gas and the amount of doping and inert gas added during deposition were changed in a systematic manner. The d.c. conductivity was measured in the temperature range 80 to 500 K. The conductivity behaviour of the investigated samples, as well as to our knowledge that of all samples investigated by other authors, can be described in a uniform way by a characteristic temperature Θ (≊ 1500 K). At this temperature the extrapolated conductivity of all samples should be the same. This behaviour will be discussed in the context of different conductivity models as, for example the variable-range hopping, transport in band-tail states and hopping between graphite-like clusters, a statistical shift of the Fermi level, and the multiphonon tunnelling model. It is shown that only the latter model can, under certain conditions, satisfactorily explain the common behaviour of the samples inve...

Amorphous hydrogenated carbon coatings (a-C:H) containing different amounts of lithium have been prepared by a modified radio frequency-plasma assisted chemical vapour deposition (rf-PACVD) technique. They have been characterized in situ by X-ray (XPS) and ultraviolet photoelectron spectroscopy (UPS). The samples have been exposed to molecular oxygen as well as an oxygen plasma in order to obtain information about the reactivity of the coatings. The effect of the oxygen plasma on pure a-C:H is found to be a mere etching, the structure of the surface itself remaining essentially unchanged. In contrast, a transition from the carbidic carbon-lithium phase to a metal-carbonate like configuration, i.e. Li 2 CO 3 or LiHCO 3 , occurs in the lithium containing samples. These differences result in a much larger oxygen uptake at the surface of the lithium containing samples as compared to the pure a-C:H. Furthermore the rate of etching by the oxygen plasma is substantially lower for the lithium containing films.

Amorphous hydrogenated carbon (a-C:H) coatings containing different amounts of lithium have been prepared by a modified radio frequency-Plasma Assisted Chemical Vapour Deposition technique. Films ranging from pure a-C:H to a-C:H containing up to 45 at.% lithium have been synthesized. The resulting layers have been characterized in-situ by X-ray and ultraviolet photoelectron spectroscopy. Carbidic bonds between lithium and part of the carbon are formed. Shift of the a-C:H related component of the C 1s core line and displacement of the valence band in dependence of the lithium content of the films indicate a charge transfer. Lithium therefore seems to be incorporated into different carbon environments. However, the samples neither contain clusters of metallic lithium nor the carbidic compound formed is metallic.

Amorphous hydrogenated carbon (a-C:H) films prepared by plasma-assisted chemical vapor deposition were investigated with respect to their possible semiconducting properties, especially their changes upon doping. Compared with pure a-C:H films, it was found that in films containing nitrogen, phosphorus or boron, both the electrical conductivity and the optical properties of the films were changed—the conductivity and the relative density of states at the Fermi level increased, while the optical bandgap decreased. For films prepared with various concentrations of dopants, as well as under various conditions of preparation, there was always found to be a strong correlation between the conductivity and the optical properties; only for very low concentrations of the dopants did the conductivity of the films increase slightly without a simultaneous decrease in the optical bandgap. Together with the temperature dependence of the conductivity—which for all films was in accordance with a variable range hopping mechanism in the temperature range 80–300 K—these results give no evidence for a shift of the Fermi level with respect to the bandgap of the material. Therefore, we conclude that no doping effect in a classical sense is achieved by the incorporation of nitrogen, phosphorus or boron into a-C:H.

A conducting plasma polymer has been found by plasma polymerization of tetracyanoquinodimethane (TCNQ) with quinoline. Plasma-polymerized quinoline and plasma-polymerized TCNQ alone each exhibit a very low conductivity ( −12 Ω −1 cm −1 for quinoline and 10 −9 Ω −9 cm −1 for TCNQ), whereas a value of about 10 −5 Ω −1 cm −1 has been measured for plasma polymers prepared from a mixture of TCNQ and quinoline. The electronic structure of these plasma polymers has been characterized in situ by ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). The electrical conductivity at room temperature of these plasma polymers was measured by the four-probe method. The temperature dependence of the conductivity was measured by the two-probe method.

Recent redshift surveys of the Nilson-, Zwicky-, and ESO-Uppsala galaxy catalogues revealed that the bright galaxies in these catalogues follow a spatial distribution where large empty regions are surrounded by sheet-like structures of galaxies and clusters (e.g. Giovanelli & Haynes 1991). From an observer's point of view, one may simply ask if the voids in the above-mentioned galaxy maps are real or if they reflect special observational selection effects, e.g. in surface brightness, integral magnitude or diameter. These catalogues contain many bright galaxies (MB ∼ M∗ B), but only very few faint objects (MB ≥ M∗B + 3 m ). Older work on the distribution of intrinsically faint galaxies, like irregular dwarfs, claimed that the dwarfs follow the distribution which is outlined by the giant galaxies.

The exchange stiffness constants of chemically disordered ${\text{Fe}}_{x}{\text{Pt}}_{1\ensuremath{-}x}$ films with thickness around 50 nm were determined by means of ferromagnetic resonance. It was found to increase with increasing Fe content from $6\ifmmode\pm\else\textpm\fi{}4\text{ }\text{pJ}/\text{m}$ for $x=0.27$ to $15\ifmmode\pm\else\textpm\fi{}4\text{ }\text{pJ}/\text{m}$ for $x=0.67$. Theoretical results from fully relativistic and scalar-relativistic band-structure calculations using the Korringa-Kohn-Rostoker method confirm the experimentally obtained values. In addition, determination of the magnetocrystalline anisotropy by angular-dependent measurements of the ferromagnetic resonance gave the possibility to estimate the exchange length that was found to be 40--50 nm for all compositions investigated in this work.

CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs) is a next-generation instrument to be built for the 3.5m telescope at the Calar Alto Observatory by a consortium of Spanish and German institutions. Conducting a five-year exoplanet survey targeting ~ 300 M stars with the completed instrument is an integral part of the project. The CARMENES instrument consists of two separate spectrographs covering the wavelength range from 0.52 to 1.7 μm at a spectral resolution of R = 85, 000, fed by fibers from the Cassegrain focus of the telescope. The spectrographs are housed in a temperature-stabilized environment in vacuum tanks, to enable a 1m/s radial velocity precision employing a simultaneous ThAr calibration.

11 pages, 6 figures, 4 tables.-- ArXiv pre-print available at: http://arxiv.org/abs/0809.4988, We present the characterization of additional properties of the night sky at the Calar Alto observatory, following the study started by Sánchez et al. in 2007. We focus here on the night-sky brightness at the near-infrared, the telescope seeing, and the fraction of useful time at the observatory. For this study we have collected a large data set comprising 7311 near-infrared images taken regularly along the last four years for the ALHAMBRA survey (J, H, and Ks bands), together with a more reduced data set of additional near-infrared images taken for the current study. In addition, we collected the information derived by the meteorological station at the observatory during the last 10 yrs, together with the results from the cloud sensor for the last ~2 yr. We analyze the dependency of the near-infrared night-sky brightness with the air mass and the seasons, studying its origins and proposing a zenithal correction. A strong correlation is found between the night-sky brightness in the Ks band and the air temperature, with a gradient of ~ -0.08 mag per 1°C. The typical (darkest) night-sky brightness in the J, H, and Ks-band are 15.95 mag (16.95 mag), 13.99 mag (14.98 mag), and 12.39 mag (13.55 mag), respectively. These values have been derived for the first time for this observatory, showing that Calar Alto is as dark in the near-infrared as most of the other astronomical sites in the world with which we could compare it. Only Mauna Kea is clearly darker in the Ks band, but not only compared to Calar Alto but to any other observatory in the world. The typical telescope seeing and its distribution were derived on the basis of the FWHM of the stars detected in the considered near-infrared images. This value, ~1.0" when converted to the V band, is only slightly larger than the atmospheric seeing measured at the same time by the seeing monitor, ~0.9". Therefore, the effects different from the atmosphere produce a reduced degradation on the telescope seeing, of the order of ~10%. Finally we estimate the fraction of useful time based on the relative humidity, gust wind speed, and presence of clouds. This fraction, ~72%, is very similar to the one derived in 2007, based on the fraction of time when the extinction monitor is working., SFS thanks the Spanish Plan Nacional de Astronomía program AYA2005-09413-C02-02, of the Spanish Ministry of Education and Science and the Plan Andaluz de Investigación of Junta de Andalucía as research group FQM322. We acknowledge Dr. M.Moles, PI of the ALHAMBRA survey, for allowing us the access to the data of this project.

Doping Ni80Fe20 by heavy rare earth atoms alters the magnetic relaxation properties of this material drastically. We show that this effect can be well explained by the slow relaxing impurity mechanism. This process is a consequence of the anisotropy of the on site exchange interaction between the 4f magnetic moments and the conduction band. As expected from this model the magnitude of the damping effect scales with the anisotropy of the exchange interaction and increases by an order of magnitude at low temperatures. In addition, our measurements allow us to determine the relaxation time of the 4f electrons as a function of temperature.

We present an update of the lunar occultation program which is routinely carried out in the near-IR at the Calar Alto Observatory. A total of 350 events were recorded since our last report (Fors et al. 2004). In the course of eight runs we have observed, among others, late-type giants, T-Tauri stars, and infrared sources. Noteworthy was a passage of the Moon close to the galactic center, which produced a large number of events during just a few hours in July 2004. Results include the determinations of the angular diameter of RZ Ari, and the projected separations and brightness ratios for one triple and 13 binary stars, almost all of which representing first time detections. Projected separations range from 0.09arcsec to 0.007arcsec. We provide a quantitative analysis of the performance achieved in our observations in terms of angular resolution and sensitivity, which reach about 0.003arcsec and K~8.5mag, respectively. We also present a statistical discussion of our sample, and in particular of the frequency of detection of binaries among field stars., 8 pages, 2 figures. Accepted for publication in A&A

An overview of media properties and their influence on the recording process in thermally assisted magnetic recording (TAR) will be given. A novel media scheme using exchange coupled FePt/FeRh bi-layers that attempts to circumvent some of the limitations encountered by 'simple' ferromagnetic media will be discussed. Utilizing the exchange spring behavior of the bi-layer above T/sub AF-FM/, this concept allows reversal of the magnetization of the FePt layer in fields comparable to those provided by current write heads at temperatures considerably lower than T/sub C/ of FePt without compromising the thermal stability of the storage layer.

International audience; The main atmospheric optical parameters have been measured at the Calar Alto Observatory simultaneously using the Generalized Seeing Monitor (GSM) and a Differential Image Motion Monitor (DIMM) during several nights in 2002 May. The temporal evolution of the seeing, the outer scale, the isoplanatic angle and the coherence time have been analysed. There is excellent agreement between the seeing measurements provided by the two instruments, particularly when the turbulence is slow. Indeed, the GSM measurements are corrected from the exposure time when the DIMM data were recorded for at least 5 ms. From almost three years of DIMM (at 5 m height above ground) data, a seeing of 0.92 arcsec with a standard deviation of 0.31 arcsec has been obtained for this site

We report rapid follow-up K'-band observations of the error box of the bright High Energy Transient Explorer burst GRB 020819. We find that any afterglow was fainter than K' = 19 only 9 hr after the burst. Because no optical afterglow was found, GRB 020819 represents a typical "dark burst.'' At first, we discuss if extinction by cosmic dust in the GRB host galaxy could explain the faintness of the afterglow of GRB 020819. We then turn to the entire ensemble of K-band dark afterglows. We find that extinction by cosmic dust in the GRB host galaxies is still a possible explanation for the faintness of many afterglows. In all investigated cases a combination of only a modest extinction with a modest redshift can explain the observations. However, the required extinction is very high if these bursts occurred at redshifts smaller than unity, perhaps arguing for alternative models to explain the nature of the dark bursts.

Impacts of meteoroids on the Moon should cause detectable optical flashes1, but the population of objects that are big enough is very low, and hitherto no unambiguous impact flashes have been recorded. The flux of meteoroids associated with the Leonid meteor shower of 18 November 1999 was predicted to produce observable flashes on the night side of the Moon2. Here we report the unambiguous detection of five such impact flashes, three of which were seen simultaneously by other observers3. We also observed a possible impact flash on 16 July 1999. All of the flashes were of very brief duration (

We present here CAFE, the Calar Alto Fiber-fed Echelle spectrograph, a new instrument built at the Centro Astronomico Hispano Alem\'an (CAHA). CAFE is a single fiber, high-resolution ($R\sim$70000) spectrograph, covering the wavelength range between 3650-9800\AA. It was built on the basis of the common design for Echelle spectrographs. Its main aim is to measure radial velocities of stellar objects up to $V\sim$13-14 mag with a precision as good as a few tens of $m s^{-1}$. To achieve this goal the design was simplified at maximum, removing all possible movable components, the central wavelength is fixed, so the wavelentgth coverage; no filter wheel, one slit and so on, with a particular care taken in the thermal and mechanical stability. The instrument is fully operational and publically accessible at the 2.2m telescope of the Calar Alto Observatory. In this article we describe (i) the design, summarizing its manufacturing phase; (ii) characterize the main properties of the instrument; (iii) describe the reduction pipeline; and (iv) show the results from the first light and commissioning runs. The preliminar results indicate that the instrument fulfill the specifications and it can achieve the foreseen goals. In particular, they show that the instrument is more efficient than anticipated, reaching a $S/N\sim$20 for a stellar object as faint as $V\sim$14.5 mag in $\sim$2700s integration time. The instrument is a wonderful machine for exoplanetary research (by studying large samples of possible systems cotaining massive planets), galactic dynamics (high precise radial velocities in moving groups or stellar associations) or astrochemistry., Comment: 12 pages, 23 figures; Acepted for publishing in A&A, 2013

Recent redshift surveys of the Nilson-, Zwicky-, and ESO-Uppsala galaxy catalogues revealed that the bright galaxies in these catalogues follow a spatial distribution where large empty regions are surrounded by sheet-like structures of galaxies and clusters (e.g. Giovanelli & Haynes 1991). From an observer’s point of view, one may simply ask if the voids in the above-mentioned galaxy maps are real or if they reflect special observational selection effects, e.g. in surface brightness, integral magnitude or diameter. These catalogues contain many bright galaxies (M B ∼ M B * ), but only very few faint objects (M B , ≥ M B * + 3m). Older work on the distribution of intrinsically faint galaxies, like irregular dwarfs, claimed that the dwarfs follow the distribution which is outlined by the giant galaxies

Natural and recombinant variants of the cysteine proteinase inhibitors chicken cystatin and human stefin B were characterized by determination of their inhibition constants for papain, actinidin and human cathepsins B and H. The individual contributions of the three contact regions to the binding energy of the chicken cystatin-papain complex were calculated as 36% for the N-terminal segment, 51% for the first and 13% for the second hairpin loop. Removal of the N-terminal contact region of chicken cystatin resulted in a 10000-fold lower affinity for papain. In contrast, stefin B remained a tight-binding inhibitor of papain and actinidin without its N-terminal segment. Affinity of stefin B for papain was only slightly affected by exchange of the residue predicted to bind in the S2 subsite of papain. The essential contribution of the first hairpin loop to inhibitor binding was confirmed by the 240-fold lower affinity for papain of a Val48----Asp mutant of stefin B. Inhibition of cathepsin B by stefins A and B is slow-binding. Binding of stefin B, not of stefin A, follows a two-step mechanism involving a slow isomerisation of the enzyme-inhibitor complex.

We present the data and initial results from a combined Hubble Space Telescope (HST)/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-1989. IUE spectra were obtained once every 2 days for a period of 74 days beginning on 1993 March 14. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October-1993 September, although many of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies.

Measurements of optical emission-line flux variations based on spectra of the Seyfert galaxy NGC 5548 obtained between December 1988 and October 1989 are reported. All of the measured optical emission lines, H-alpha, H-beta, H-gamma, He I 5876, and He II 4686, exhibit the same qualitative behavior as the UV and optical continua, but with short time delays, or lags, which are different for the various lines. Cross-correlation analysis is applied to measure the lags between the various lines and the continuum. Similar lags are found with respect to the UV continuum for H-alpha and H-beta, 17 and 19 d, respectively. The lag for H-gamma is shorter (13 d), only somewhat larger than the lag measured for Ly-alpha (about 10 d). The helium lines respond to continuum variations more rapidly than the hydrogen lines, with lags of about 7 d for He II 4686 and 11 d for He I 5876.

We present measurements of the Balmer continuum/Fe II emission blend between 2160 and 4130 A in the Seyfert galaxy NGC 5548. The measurements are from spectra obtained as part of the combined space-based and ground-based monitoring program of this object in 1988-1989. An iterative scheme is used to determine and subtract the continuum emission underlying the emission blend so as to obtain a light curve sampled once every four days. The small blue bump is an important component of the emission-line cooling, constituting about one third of the line flux in this object. Its flux varies with an amplitude of approximately +/- 20 percent about the mean, similar to the amplitude of the Balmer line variations during the same period. Its light curve resembles that of Ly-alpha, with a lag of about 10 days behind the continuum variations. The bump variation amplitude is independent of the wavelength interval where it is measured, which indicates that both the Balmer continuum and Fe II emission have comparable variation amplitudes. These results suggest that the Fe II UV multiplets and the Balmer continuum are emitted in the same parts of the broad-line region as most other broad emission lines in this object.

A large, international program of ground-based optical spectroscopy and photometry of the variable Seyfert 1 galaxy NGC 5548 undertaken in support of an IUE monitoring campaign is described. This contribution presents the data base and describes the methods used to correct for systematic differences between spectra from different sources. Optical continuum and H-beta emission-line light curves are derived from the spectra. The behavior of the optical continuum is qualitatively the same as the behavior of the ultraviolet continuum. Cross-correlation of the ultraviolet and optical continuum measurements does not reveal any significant lag between them. The h-beta emission-line variations show the same basic pattern as seen in the continuum and ultraviolet emission lines, with H-beta lagging behind the continuum by about 20 days. This is significantly larger than the about 10 day lag deduced for Ly-alpha.

15 Carabiden-Arten von Uferstandorten (7 Arten den Auwalder, 8 Arten der freien Uferflachen) wurden experimentell auf Helligkeits-und Temperaturpraferenz gepruft. Die Untersuchung erfolgte in isolierten Helligkeits- und Temperaturgradienten und in zwei verschiedenen Kombinationen von Temperatur- und Helligkeitsgefalle. Wald- und Freilandtiere unterscheiden sich in charakteristischer Weise. Bei der Kombination verschiedenen Gradienten orientieren sich 5 von 7 Waldtieren gemas ihrer Helligkeitspraferenz, 5 von 8 Freilandtieren gemas ihrer Temperaturpraferenz. Nur wenige Arten zeigen in den Kombinationsversuchen ein intermediares, von beiden Faktoren bestimmtes Orientierungsverhalten.

In answer to Mansingh’s criticism the value of Müller’s system of dormancies is emphasized. It gives especially a clear differentiation between the obligatory dormancy called parapause, which is under the control of only one environmental factor, and the facultative eudiapause, where different factors are working respectively as inducing and terminating. The carabid beetles are an example that illustrates that no narrow correlation can be found between the distribution of dormancy types and the climatic zones on the earth they live in.

Larven von Pterostichus vulgaris verfallen bei Temperaturen von mehr als etwa 15° am Ende des 2. Larvenstadiums in eine Diapause. Diese wird durch Einwirkung niedriger Temperatur auf das 2. Stadium wenig beeinflust. Behandlung des 3. Stadiums mit niedriger Temperatur fuhrt dagegen zur Uberwindung der Diapause, wobei 6-monatige Behandlung bei + 4 bis 5° in nachfolgender Warme hohere Metamorphoseraten (14–18%) bewirkt als 4-monatige Einwirkung von +6 bis 7° (2–4%). Die hochsten Metamorphoseraten (24–28%) erhalt man nach dem Einflus der naturlichen Winterkalte im Freiland. Die Photoperiode beeinflust die Entwicklung von P. vulgaris nicht. Bei gleichem Temperatureinflus zeigten unter Kurztag und Langtag behandelte Versuchstiergruppen die gleiche Mortalitat und Metamorphoserate. Es wird vorgeschlagen, den Entwicklungsgang von P. vulgaris als “thermisch gesteuerte Parapause” in das System der Dormanztypen von Muller einzuordnen.

The crystal structure of chicken egg white cystatin has been solved by X-ray diffraction methods using the multiple isomorphous replacement technique. Its structure has been refined to a crystallographic R value of 0.19 using X-ray data between 6 and 2.0A. The molecule consists mainly of a straight five-turn alpha-helix, a five-stranded antiparallel beta-pleated sheet which is twisted and wrapped around the alpha-helix and an appending segment of partially alpha-helical geometry. The 'highly conserved' region from Gln53I to Gly57I implicated with binding to cysteine proteinases folds into a tight beta-hairpin loop which on opposite sides is flanked by the amino-terminal segment and by a second hairpin loop made up of the similarly conserved segment Pro103I - Trp104I. These loops and the amino-terminal Gly9I - Ala10I form a wedge-shaped 'edge' which is quite complementary to the 'active site cleft' of papain. Docking experiments suggest a unique model for the interaction of cystatin and papain: according to it both hairpin loops of cystatin make major binding interactions with the highly conserved residues Gly23, Gln19, Trp177 and Ala136 of papain in the neighbourhood of the reactive site Cys25; the amino-terminal segment Gly9I - Ala10I of bound cystatin is directed towards the substrate subsite S2, but in an inappropriate conformation and too far away to be attacked by the reactive site Cys25. As a consequence, the mechanism of the interaction between cysteine proteinases and their cystatin-like inhibitors seems to be fundamentally different from the 'standard mechanism' defined for serine proteinases and most of their protein inhibitors.

CCD images and photographic spectra of Seyfert galaxies have been recently obtained by the authors at the Cassegrain focus of the 2.2m, F/8 telescope of the Calar Alto Observatory (D.S.A.Z.). The main purposes of the observing programme were essentially three: 1) To obtain medium resolution spectra and high quality images of interacting active nuclei in order to study in detail their physical and morphological features and to verify whether nuclear activity can be related to some external disturbances. 2) To monitor some previously observed Seyfert-1 galaxies in order to detect changes in their emission line spectra. 3) To verify the spectral features of some objects remarkable within the Seyfert class for their peculiar line profiles and/or intensity line ratios.