The Extreme Conditions Beamline P02.2 and the Extreme Conditions Science Infrastructure at PETRA III

A detailed description is presented of the Extreme Conditions Beamline P02.2 for micro X-ray diffraction studies of matter at simultaneous high pressure and high/low temperatures at PETRA III, in Hamburg, Germany. This includes performance of the X-ray optics and instrumental resolution as well as an overview of the different sample environments available for high-pressure studies in the diamond anvil cell. Particularly emphasized are the high-brilliance and high-energy X-ray diffraction capabilities of the beamline in conjunction with the use of fast area detectors to conduct time-resolved compression studies in the millisecond time regime. Finally, the current capability of the Extreme Conditions Science Infrastructure to support high-pressure research at the Extreme Conditions Beamline and other PETRA III beamlines is described.

Intensity interferometry of single x-ray pulses from a synchrotron storage ring

We report on measurements of second-order intensity correlations at the high-brilliance storage ring PETRA III using a prototype of the newly developed adaptive gain integrating pixel detector. The detector records individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV and repetition rate of about 5 MHz. The second-order intensity correlation function is measured simultaneously at different spatial separations, which allows us to determine the transverse coherence length at these x-ray energies. The measured values are in a good agreement with theoretical simulations based on the Gaussian Schell model.

Resonant scattering and diffraction beamline P09 at PETRA III

The resonant scattering and diffraction beamline P09 at PETRA III is designed for X-ray experiments requiring small beams, energy tunability, variable polarization and high photon flux. It is highly flexible in terms of beam size and offers full higher harmonic suppression. A state-of-the-art double phase-retarder set-up provides variable linear or circular polarization. A high-precision Psi-diffractometer and a heavy-load diffractometer in horizontal Psi-geometry allow the accommodation of a wide variety of sample environments. A 14 T cryo-magnet is available for scattering experiments in magnetic fields.

Performance of complex snow cover descriptions in a distributed hydrological model system: A case study for the high Alpine terrain of the Berchtesgaden Alps

[1] Runoff generation in Alpine regions is typically affected by snow processes. Snow accumulation, storage, redistribution, and ablation control the availability of water. In this study, several robust parameterizations describing snow processes in Alpine environments were implemented in a fully distributed, physically based hydrological model. Snow cover development is simulated using different methods from a simple temperature index approach, followed by an energy balance scheme, to additionally accounting for gravitational and wind-driven lateral snow redistribution. Test site for the study is the Berchtesgaden National Park (Bavarian Alps, Germany) which is characterized by extreme topography and climate conditions. The performance of the model system in reproducing snow cover dynamics and resulting discharge generation is analyzed and validated via measurements of snow water equivalent and snow depth, satellite-based remote sensing data, and runoff gauge data. Model efficiency (the Nash-Sutcliffe coefficient) for simulated runoff increases from 0.57 to 0.68 in a high Alpine headwater catchment and from 0.62 to 0.64 in total with increasing snow model complexity. In particular, the results show that the introduction of the energy balance scheme reproduces daily fluctuations in the snowmelt rates that trace down to the channel stream. These daily cycles measured in snowmelt and resulting runoff rates could not be reproduced by using the temperature index approach. In addition, accounting for lateral snow transport changes the seasonal distribution of modeled snowmelt amounts, which leads to a higher accuracy in modeling runoff characteristics.

Linking altitudinal gradients and temperature responses of plant phenology in the Bavarian Alps

Global climate change influences ecosystems across the world. Alpine plant communities have already experienced serious impacts, and will continue to do so as climate change continues. The aim of our study was to determine the sensitivity of woody and herbaceous species to shifts in temperature along an altitudinal gradient. Since 1994, park rangers have been making phenological observations at 24 sites from 680 to 1425 m a.s.l. Each year 21 plant species were observed once or twice weekly from March to July; with a main focus on flowering and leaf unfolding. Our study showed a very high degree of dependence of phenophases and species on inter-annual temperature variation and altitude. Averaged over all species and phenophases, there was a delay of 3.8 days with every 100 m increase in altitude and, across all elevations, an advance of phenophases of 6 days per 1 °C increase in temperature. Temperature lapse rates assessed indirectly by phenology, as the quotient of altitudinal to temperature response coefficients, were higher than directly calculated from March to July mean temperatures, most likely due to snow effects. Furthermore, a significant difference in sensitivity to temperature change was found between growth forms (herbs versus trees). Sensitivity was less pronounced in events occurring later in the season. Our results show that species reactions will differ in magnitude during global warming. Consequently, impacts of shifts in the timing of phenological events on plant migration and plant-pollinator interactions due to rising temperatures should be considered at the species level.

The high-resolution diffraction beamline P08 at PETRA III

The new third-generation synchrotron radiation source PETRA III located at the Deutsches Elektronen-Synchrotron DESY in Hamburg, Germany, has been operational since the second half of 2009. PETRA III is designed to deliver hard X-ray beams with very high brilliance. As one of the first beamlines of PETRA III the high-resolution diffraction beamline P08 is fully operational. P08 is specialized in X-ray scattering and diffraction experiments on solids and liquids where extreme high resolution in reciprocal space is required. The resolving power results in the high-quality PETRA III beam and unique optical elements such as a large-offset monochromator and beryllium lens changers. A high-precision six-circle diffractometer for solid samples and a specially designed liquid diffractometer are installed in the experimental hutch. Regular users have been accepted since summer 2010.

Small Angle Scattering from Nanocrystalline Pd

The microstructure of nanocrystalline Pd was investigated by small angle scattering of neutrons and X-rays. The samples were prepared by compacting small crystallites produced by evaporation and condensation in an inert gas atmosphere. The strong scattering signal is interpreted to arise from crystallites embedded in a matrix of incoherent interfaces. Size distributions were deduced from the scattering curves. They consist of two parts: the crystallite size distribution dictated by the production process, and a structureless contribution due to the correlation in the spatial arrangement of the crystallites. The crystallite size distribution may be described by a log-normal distribution centred at R=2nm. The characteristic form of the correlation contribution arises from the dense packing of non-spherical crystallites. From the scattering cross-section in absolute units the volume fraction vc of crystallites was obtained as vc≈0.3, and the mean atomic density ρi in the interfaces as ρi≈0.52. The change of structural parameters during thermal annealing of the samples was studied. Up to high temperatures an appreciable volume fraction of crystallites with nearly unchanged size remains along with large particles.

Dynamics at the liquid-vapor interface of a supercooled organic glass former

We investigated the dynamics near the liquid-vapor interface of the supercooled model organic glass former dibutyl phthalate by using surface-sensitive x-ray scattering techniques. Our results reveal significant enhancement of the relaxation rate over a wide length-scales range. The analysis of the dispersion relation of long-wavelength surface fluctuations yields a nonzero value of the share modulus near the free surface. At the molecular level, the dynamics in the near surface region (10-15 nm) is inhomogeneous. The mobility is decreasing with increasing distance from the free surface. Below the bulk glass transition, two distinct relaxation times were observed differing by 1 order of magnitude. The observed fast relaxation proves the existence of a high mobility liquidlike surface layer of 10 nm thickness on top of a frozen in bulk system.

Modelling the atomic structure of Al92U8 metallic glass

The local atomic structure of the glassy Al(92)U(8) alloy was modelled by the reverse Monte Carlo (RMC) method, fitting x-ray diffraction (XRD) and extended x-ray absorption fine structure (EXAFS) signals. The final structural model was analysed by means of partial pair correlation functions, coordination number distributions and Voronoi tessellation. In our study we found that the most probable atomic separations between Al-Al and U-Al pairs in the glassy Al(92)U(8) alloy are 2.7 Å and 3.1 Å with coordination numbers 11.7 and 17.1, respectively. The Voronoi analysis did not support evidence of the existence of well-defined building blocks directly embedded in the amorphous matrix. The dense-random-packing model seems to be adequate for describing the connection between solvent and solute atoms.

Age and sex as predictors of biochemical activity in acromegaly: analysis of 1485 patients from the German Acromegaly Register

OBJECTIVE

We evaluated the German Acromegaly Register for clinical variables associated with the initial biochemical activity of patients with acromegaly.

DESIGN

Retrospective analysis of data in the registry.

PATIENTS

A total of 1485 patients with acromegaly (males 45.6%, females 54.4%) were treated in 42 German endocrine centres until November 2005. Linear regression models were used to estimate the influence of various parameters on biochemical activity.

RESULTS

Male patients with acromegaly were significantly younger at the time of diagnosis than female patients (41 vs. 47 years, P < 0.0001) and had significantly higher random GH levels than females (21 vs. 14 ng/ml, P < 0.005) and IGF-1 levels (773 vs. 679 ng/ml, P < 0.0001), respectively. Age at initial presentation turned out to be the most important independent risk factor associated with random GH levels, oral glucose tolerance test-suppressed GH levels, IGF-1 levels, body mass index (BMI), tumour size and prevalence of hypopituitarism. Sex was an independent risk factor for IGF-1 levels, BMI and prevalence of hypopituitarism. Tumour size was an independent risk factor for both GH and IGF-1 levels.

CONCLUSIONS

In summary, initial biochemical activity of acromegaly is influenced by patient's age and to a lesser degree by patient's sex. Male patients are on an average 6 years younger than females.

Results of surgical and somatostatin analog therapies and their combination in acromegaly: a retrospective analysis of the German Acromegaly Register

BACKGROUND

Data on surgical and medical treatment outcomes in acromegaly mostly originate from specialized centers. We retrospectively analyzed the data on surgery, primary somatostatin analog (SSA) therapy, surgery preceded by SSA, and SSA preceded by surgery in 1485 patients from the German Acromegaly Register.

METHODS

Two trained nurses visited all centers (N=42) for data acquisition.

RESULTS

Primary surgery: out of 889 patients, 554 yielded analyzable data (microadenomas 22.9%, macroadenomas 77.1%). GH and IGF1 normalized in 54.3 and 67.2%. Partial or total pituitary insufficiency occurred in 28.6% initially and 41.2% post-surgery. Primary SSA (>or=3 months): out of 329 patients, 145 yielded analyzable data (microadenomas 26.7%, macroadenomas 73.3%). GH and IGF1 normalized in 36.3 and 30.5%, increasing to 40.8 and 41.5% with longer SSA (>or=360 days) in 54 patients. Pituitary function did not change. SSA (>or=3 months) prior to surgery: out of 234 patients, 93 yielded analyzable data. Post-surgery GH and IGF1 was normalized in 62.9 and 68.4%. GH improvement was slightly, but significantly better after SSA pretreatment. Surgery followed by SSA: out of 122 patients, 34 yielded analyzable data. GH and IGF1 normalized during SSA in 24.1 and 45.5%. Relative GH decrease was significantly larger compared with primary SSA.

CONCLUSIONS

Pituitary surgery was more effective to lower GH and IGF1 concentrations than primary SSA. Primary SSA may be an option in selected patients. SSA prior to surgery only marginally improved surgical outcome. Debulking surgery may result in better final outcome in patients with a high GH concentration and a large tumor.

New class of plastic bulk metallic glass

An intrinsic plastic Cu(45)Zr(46)Al(7)Ti(2) bulk metallic glass (BMG) with high strength and superior compressive plastic strain of up to 32.5% was successfully fabricated by copper mold casting. The superior compressive plastic strain was attributed to a large amount of randomly distributed free volume induced by Ti minor alloying, which results in extensive shear band formation, branching, interaction and self-healing of minor cracks. The mechanism of plasticity presented here suggests that the creation of a large amount of free volume in BMGs by minor alloying or other methods might be a promising new way to enhance the plasticity of BMGs.

The influence of short-time ball-milling on the stability of amorphous CoFeB alloys

The influence of short-time milling on the atomic structure of amorphous Co(70.3)Fe(4.7)B(25) has been investigated by differential scanning calorimetry (DSC), x-ray powder diffraction (XRD), vibrating sample magnetometer (VSM) and x-ray absorption fine-structure (XAFS) techniques. Our results prove that the milling process crystallizes the initially amorphous sample and that the degree of inherent crystallization is inversely proportional to the powder particle size. The investigation of the local atomic structure documents very similar environments around the Co and Fe atoms. The high-energy ball-milling of amorphous precursor represents a practical way to prepare powders having the desired amorphous/nanocrystalline microstructure.

The German Acromegaly Registry: Description of the Database and Initial Results

Patient registries are valuable tools to study long-term morbidity and mortality of rare diseases. Acromegaly is rare (incidence 3-4/mill/year, prevalence 40-70/mill; approx. 300 new patients/yr and up to 5700 patients in Germany). Diagnostic and therapeutic possibilities have considerably improved, but treatment results remain often unsatisfactory. The main cause is residual disease activity after surgery, most importantly due to invasive macroadenomas. The German Acromegaly Registry is an initiative of the Pituitary Study Group of the German Endocrine Society (DGE). Formally established in January 2003 by the Board of the DGE, long-term financial support is guaranteed by an unrestricted grant from Novartis Pharma GmbH to the DGE. The registry cooperates closely with the United Kingdom and the Austrian registries. The aim of the German Acromegaly Registry is to establish a database of sufficient epidemiological strength in order to (1) document co-morbidity and mortality, (2) provide data on diagnostic and therapeutic procedures/effectiveness, (3) enable comparison of procedures in different national centres, (4) provide information for patient support groups/interaction with health care providers, (5) enable comparison with other national registries within Europe. The registry has at present 82 participating centres, and 42 have included patients (20 university clinics, 8 non-university hospitals, 14 centres in private practice). The database aims to include all acromegalic patients in Germany who are cared for and treated at present. Up to December 2005 1543 patients have been entered in a retrospective manner. Data collection is by external monitoring by highly trained study nurses who visit the individual centres. Inclusion is planned to continue at a rate of 500 per year. Starting in 2005 centres are revisited every 3 years at a rate of 500 per year (prospective phase of the registry). Quality of the data has been validated by an independent monitoring team which demonstrated high data concordance.

CONCLUSIONS

Initial results of the German Acromegaly Registry show that it was possible to include a large number of patients within 3 years into the registry. Data quality has been validated and shown to be satisfactory. Therefore, the registry will be a useful tool to study long-term morbidity and mortality in a large series of patients.

Amorphouslike diffraction pattern in solid metallic titanium

Amorphouslike diffraction patterns of solid elemental titanium have been detected under high pressure and high temperature using in situ energy-dispersive x-ray diffraction and a multianvil press. The onset pressure and the temperature of formation of amorphous titanium is found to be close to the alpha-beta-omega triple point in the P-T phase diagram. Amorphous Ti has been found to be thermally stable up to 1250 degrees C for at least 3 min at some pressures. By analyzing the conditions for producing amorphous elemental Zr and Ti, we observed a multi-phase-point amorphization phenomenon for preparing single-element bulk amorphous metals. The results reported may open a new way to preparing single-element bulk amorphous metals with a high thermal stability.

Innervation zones of the external anal sphincter in healthy male and female subjects. Preliminary results

OBJECTIVES

The objective of this work was to investigate the distribution of the innervation zones of the motor units that make up the external anal sphincter (EAS) in healthy males and females.

METHODS

A cylindrical probe carrying a circumferential array of 16 electrodes was used to detect the generation, propagation and extinction of individual motor unit action potentials (MUAPs) at 1, 2, and 3 cm depth from the orifice of the anal canal during maximal voluntary contractions of the EAS. Fifteen healthy males and 37 healthy nulliparous females were investigated.

RESULTS

IZs could be detected in all males and in 34 out of 37 females. In the males, the IZs are scattered in the right and left hemisphincter at each of the three levels and their distribution is not affected by depth. In the females, the distribution is also concentrated in the right and left hemisphincter at depth 1 cm but is more uniform at depth 2 cm and more concentrated in the dorsal and ventral regions at depth 3 cm. ANOVA shows a statistically significant dependence of the IZ distribution on depth only in females and not in males.

CONCLUSIONS

It is concluded that (a) IZs of the EAS can indeed be detected with a circumferential array placed at different depths along the anal canal; (b) large individual variability is observed, and (c) IZs show similar distribution at the three depth levels in males and different distributions in females.

Confined phonons in glasses. A study by nuclear inelastic absorption and Raman scattering

We have applied nuclear inelastic absorption (NIA) to the molecular glass former dibutyl phthalate/ferrocene, both in bulk and in nanoporous matrices having pore sizes of 50 and 25 A. The quantity g(E)/E(2), where g(E) is the vibrational density of states (VDOS) of the iron atoms, exhibits a pronounced maximum around 2 meV. Confinement in pores leads to a suppression of the VDOS below 1.5 meV, independent of the pore size. The influence of local interactions at the pore wall was assessed using Raman scattering. Our observations are discussed in the light of experimental and theoretical results on nanoparticles and for the Boson peak.

Visual discrimination learning of group-housed goats at an automated learning device

Abstract. A general purpose computer system for behavioral conditioning experiments, the "Fields-Monitor", was developed and has been in use for several years. The set-up allows flexible stimulus presentations and rewards for different kinds of learning behavior in animals. It enables training and testing of animals even under group housing conditions which prevent the social isolation and possible distorting influences resulting from the experimenter or from the time of the day (the test animals visit the learning device whenever they want). Thus, it eliminates most of the stress factors known to decrease learning success. Using this device, 160 dwarf goats were trained for visual discrimination of four stimulus patterns (simple geometric figures, Roman letters) presented simultaneously. One of these patterns was rewarded with a small portion of water after each correct choice. A comparison of mean learning curves in the three consecutive tests showed that in the second and third test successful learning started earlier and reached a higher level (70–80% correct choices as early as the 5–6th Test Day) than in Test 1 (about 60% correct choices at the 10th Test Day). The coefficient of variation of average learning success for 10 days was 28.4, 18.7, 16.8 % in Test 1–3 respectively, indicating great differences between the animals. All animals could use the learning equipment voluntarily over several weeks, without any social deprivation.

Zum Einfluss der Trainingsmethode auf das Lernverhalten von Zwergziegen am Computer

Abstract. Title of the paper: The Influence of training methods on learning behaviour of dwarf goats on an automatic learning device In learning experiments with 67 Dwarf Goat kids on a general purpose Computer system for behavioural conditioning experiments, named "Field Monitor", it was tested, how to train successful animals on automated learning devices. Using 4 simultaneously offered visual Stimuli whose arrangement varies randomly in consecutive offers, a substantial side preference (a subject chose one side more frequently than the other) was frequently developed by the test animals. Such behavioural strategy could be effectively overcome by a special Software which presented for some test intervals only the non rewarded S- patterns on the preferred side.

Ein Vergleich des Lernerfolges von Zwergziegen bei simultaner Zweifach- oder Vierfachwahlmöglichkeit in visuellen Differenzierungsaufgaben

Abstract. Title of the paper: A comparison of learning Performance of dwarf goats in Visual discrimination tasks with two or four simultaneously offered Stimuli A comparison of learning Performance of dwarf goats in visual discrimination tasks with two or four simultaneously offered Stimuli (two-choice and four-choice design) was carried out with the automatic learning device 'Field Monitor'. One S+ Stimulus and three identical S- Stimuli by the four-choice design, and one S+ Stimulus and one S− Stimulus (the same patterns as by four choice) by two-choice design were offered. In both experimental designs the positions of Stimuli (simple geometric figures) on the screen changed pseudo-randomly after each choice. Since the seventh test day the proportion of successfully learning kids by the four-choice design was substantially higher than that for the two-choice design. Our finding makes it questionable whether the internationally accepted two-choice design is really optimal. In our further experiments in which over 200 animals have been examined for several months the four-choice design has been involved providing a very successful learning.

Direct determination of metastable phase diagram by synchrotron radiation experiments on undercooled metallic melts

The phase selection process during the crystallization of undercooled metallic melts is studied in situ by combining the electromagnetic levitation technique with energy dispersive x-ray diffraction of synchrotron radiation. The crystallization of metastable bcc phase in binary Ni-V alloys was identified. A metastable phase diagram of Ni-V alloy is constructed, which shows the primarily solidifying phase as a function of composition and undercooling. The analysis within nucleation theory emphasizes the important role of metal oxide as a heterogeneous nucleation site controlling the phase selection.

Effect of melatonin and pineal extracts on human ovarian and mammary tumor cells in a chemosensitivity assay

Pinealectomy enhances tumor growth and metastatic spread in experimental animals. This effect is only in part due to melatonin since melatonin-free pineal extracts containing yet unidentified pineal substances have also shown tumor inhibiting activity. Despite numerous reports suggesting melatonin as a potential anti-cancer agent there have not been sufficient clinical trials to define the actual therapeutic potential of melatonin for the treatment of human cancers. To help fill this gap, we used a chemosensitivity assay designed to test the sensitivity of tumors from individual patients towards chemotherapeutic drugs for assessing the effect of melatonin and pineal extracts on primary human tumor cells. Primary cell cultures from seven ovarian and six mammary tumors were incubated with melatonin, the pineal extract YC05R (containing substances between 500 and 1000 daltons) and chemotherapeutic drugs. The pineal extract YC05R inhibited growth of all tumors in a dose-dependent manner. Physiological concentrations of melatonin (10(-8)-10(-10) M) inhibited the growth of one out of six mammary carcinomas in a dose-dependent manner. Primary cell cultures from three ovarian tumors were affected by melatonin in different ways, i.e., two were inhibited and one was slightly stimulated. There was no correlation between sensitivity towards melatonin and sex steroid receptor status, stage or grade of the tumor. It is concluded that, 1), melatonin may be an inhibitor of human mammary and ovarian carcinoma in individual cases and, 2), the pineal gland contains very active anti-tumor substances inhibiting both, the mammary and ovarian tumors, tested. These substances require chemical and biological identification.