Search

The effective radiative forcing (ERF) due to aerosol–cloud interactions (ACIs) and rapid adjustments (ERFaci) still causes the largest uncertainty in the assessment of climate change. It is understood only with medium confidence and is studied primarily for warm clouds. Here, we present a novel cloud-by-cloud (C×C) approach for studying ACI in satellite observations that combines the concentration of cloud condensation nuclei (nCCN) and ice nucleating particles (nINP) from polar-orbiting lidar measurements with the development of the properties of individual clouds by tracking them in geostationary observations. We present a step-by-step description for obtaining matched aerosol–cloud cases. The application to satellite observations over central Europe and northern Africa during 2014, together with rigorous quality assurance, leads to 399 liquid-only clouds and 95 ice-containing clouds that can be matched to surrounding nCCN and nINP respectively at cloud level. We use this initial data set for assessing the impact of changes in cloud-relevant aerosol concentrations on the cloud droplet number concentration (Nd) and effective radius (reff) of liquid clouds and the phase of clouds in the regime of heterogeneous ice formation. We find a Δln⁡Nd/Δln⁡nCCN of 0.13 to 0.30, which is at the lower end of commonly inferred values of 0.3 to 0.8. The Δln⁡reff/Δln⁡nCCN between −0.09 and −0.21 suggests that reff decreases by −0.81 to −3.78 nm per increase in nCCN of 1 cm−3. We also find a tendency towards more cloud ice and more fully glaciated clouds with increasing nINP that cannot be explained by the increasingly lower cloud top temperature of supercooled-liquid, mixed-phase, and fully glaciated clouds alone. Applied to a larger number of observations, the C×C approach has the potential to enable the systematic investigation of warm and cold clouds. This marks a step change in the quantification of ERFaci from space.

Abstract Background Coronavirus disease 2019 (COVID-19) results in debilitating long-term symptoms, often referred to as Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), in a substantial subgroup of patients. One of the most prevalent symptoms following COVID-19 is severe fatigue. Prompt delivery of cognitive behavioural therapy (CBT), an evidence-based treatment that has shown benefit in reducing severe fatigue in other conditions, may reduce post-COVID-19 fatigue. Based on an existing CBT protocol, a blended intervention of 17 weeks, Fit after COVID, was developed to treat severe fatigue after the acute phase of infection with SARS-CoV-2. Method The ReCOVer study is a multicentre 2-arm randomised controlled trial (RCT) to test the efficacy of Fit after COVID on severe post-infectious fatigue. Participants are eligible if they report severe fatigue 3 up to and including 12 months following COVID-19. One hundred and fourteen participants will be randomised to either Fit after COVID or care as usual (ratio 1:1). The primary outcome, the fatigue severity subscale of the Checklist Individual Strength (CIS-fatigue), is assessed in both groups before randomisation (T0), directly post CBT or following care as usual (T1), and at follow-up 6 months after the second assessment (T2). In addition, a long-term follow-up (T3), 12 months after the second assessment, is performed in the CBT group only. The primary objective is to investigate whether CBT will lead to a significantly lower mean fatigue severity score measured with the CIS-fatigue across the first two follow-up assessments (T1 and T2) as compared to care as usual. Secondary objectives are to determine the proportion of participants no longer being severely fatigued (operationalised in different ways) at T1 and T2 and to investigate changes in physical and social functioning, in the number and severity of somatic symptoms and in problems concentrating across T1 and T2. Discussion This is the first trial testing a cognitive behavioural intervention targeting severe fatigue after COVID-19. If Fit after COVID is effective in reducing fatigue severity following COVID-19, this intervention could contribute to alleviating the long-term health consequences of COVID-19 by relieving one of its most prevalent and distressing long-term symptoms. Trial registration Netherlands Trial Register NL8947 . Registered on 14 October 2020.

Agriculture’s primary function is the production of food, feed, fibre and fuel for the fast-growing world population. However, it also affects human health and ecosystem integrity. Policymakers make policies in order to avoid harmful impacts. How to assess such policies is a challenge. In this paper, we propose a conceptual framework to help evaluate the impacts of agricultural policies on the environment. Our framework represents the global system as four subsystems and their interactions. These four components are the cells of a 2 by 2 matrix [Agriculture, Rest of the word]; [Socio-eco system, Ecological system]. We then developed a set of indicators for environmental issues and positioned these issues in the framework. To assess these issues, we used four well-known existing approaches: Life Cycle Assessment, Ecosystem Services Analysis, Yield Gap Analysis and Agro-Environmental Indicators. Using these four approaches together provided a more holistic view of the impacts of a given policy on the system. We then applied our framework on existing cover crop policies using an extensive literature survey and analysing the different environmental issues mobilised by the four assessment approaches. This demonstration case shows that our framework may be of help for a full systemic assessment. Despite their differences (aims, scales, standardization, data requirements, etc.), it is possible and profitable to use the four approaches together. This is a significant step forward, though more work is needed to produce a genuinely operational tool.

Based on the notion that the local dark-matter field of axions or axionlike particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we establish the feasibility of a new method to search for ALPs in storage rings. Based on previous work that allows us to maintain the in-plane polarization of a stored deuteron beam for a few hundred seconds, we perform a first proof-of-principle experiment at the Cooler Synchrotron (COSY) to scan momenta near 970 MeV/c. This entails a scan of the spin-precession frequency. At resonance between the spin-precession frequency of deuterons and the ALP-induced electric dipole moment (EDM) oscillation frequency, there is an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and, consequently, the spin-precession frequency are ramped to search for a vertical polarization change that occurs when the resonance is crossed. At COSY, four beam bunches with different polarization directions are used to make sure that no resonance is missed because of the unknown relative phase between the polarization precession and the axion or ALP field. A frequency window of 1.5 kHz width around the spin-precession frequency of 121 kHz is scanned. We describe the experimental procedure and a test of the methodology with the help of a radio-frequency Wien filter located on the COSY ring. No ALP resonance is observed. As a consequence, an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.

Abstract Creativity is an essential cognitive ability linked to all areas of our everyday functioning. Thus, finding a way to enhance it is of broad interest. A large number of anecdotal reports suggest that the consumption of psychedelic drugs can enhance creative thinking; however, scientific evidence is lacking. Following a double-blind, placebo-controlled, parallel-group design, we demonstrated that psilocybin (0.17 mg/kg) induced a time- and construct-related differentiation of effects on creative thinking. Acutely, psilocybin increased ratings of (spontaneous) creative insights, while decreasing (deliberate) task-based creativity. Seven days after psilocybin, number of novel ideas increased. Furthermore, we utilized an ultrahigh field multimodal brain imaging approach, and found that acute and persisting effects were predicted by within- and between-network connectivity of the default mode network. Findings add some support to historical claims that psychedelics can influence aspects of the creative process, potentially indicating them as a tool to investigate creativity and subsequent underlying neural mechanisms. Trial NL6007; psilocybin as a tool for enhanced cognitive flexibility; https://www.trialregister.nl/trial/6007 .

The observation that mountain regions generally display higher diversity than tropical regions has recently been presented as a puzzle or “enigma”, since it seems to contradict the normal belief that the highest diversity on Earth occurs in the rain forest ecosystems around the equator. The observation seems to be well supported by data gathered for several animal and plant communities, and thus deserves further attention, including investigation of how it arises. However, re-interpretation of the enigma in the light of ecosystem theory serves to resolve the problem, explaining the increased diversity as the result of the presence of a larger set of thermodynamic and thermo-chemical variables, which vary in quantity, quality, time, and space, together with the forcing functions usually present. This permits a more intensive exploitation of the gradients in an oscillating environment as formulated for instance in the intermediate disturbance hypothesis combined with the niche construction concept. Put simply, mountain regions offer an environment with a greater and more variable set of gradients, in terms of both quantity and quality, than occur in the more stable environments found in relatively flat areas. This gives an extra stimulus to speciation processes, resulting in the elevated diversity observed.

Analysis of Earth system dynamics in the Anthropocene requires explicitly taking into account the increasing magnitude of processes operating in human societies, their cultures, economies and technosphere and their growing feedback entanglement with those in the physical, chemical and biological systems of the planet. However, current state-of-the-art Earth system models do not represent dynamic human societies and their feedback interactions with the biogeophysical Earth system and macroeconomic integrated assessment models typically do so only with limited scope. This paper (i) proposes design principles for constructing world–Earth models (WEMs) for Earth system analysis of the Anthropocene, i.e., models of social (world)–ecological (Earth) coevolution on up to planetary scales, and (ii) presents the copan:CORE open simulation modeling framework for developing, composing and analyzing such WEMs based on the proposed principles. The framework provides a modular structure to flexibly construct and study WEMs. These can contain biophysical (e.g., carbon cycle dynamics), socio-metabolic or economic (e.g., economic growth or energy system changes), and sociocultural processes (e.g., voting on climate policies or changing social norms) and their feedback interactions, and they are based on elementary entity types, e.g., grid cells and social systems. Thereby, copan:CORE enables the epistemic flexibility needed for contributions towards Earth system analysis of the Anthropocene given the large diversity of competing theories and methodologies used for describing socio-metabolic or economic and sociocultural processes in the Earth system by various fields and schools of thought. To illustrate the capabilities of the framework, we present an exemplary and highly stylized WEM implemented in copan:CORE that illustrates how endogenizing sociocultural processes and feedbacks such as voting on climate policies based on socially learned environmental awareness could fundamentally change macroscopic model outcomes.

Abstract We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the synergy and complementarity of the different colliders, which will contribute to a uniquely coherent and ambitious research programme, providing an unmatchable combination of precision and sensitivity to new physics.

The global climate change calls for more environmentally friendly use of energy and has led to stricter limits and regulations for the emissions of various greenhouse gases. Consequently, there is nowadays an increasing need for the detection of exhaust and natural gases. This need leads to an ever-growing market for gas sensors, which, at the moment, is dominated by chemical sensors. Yet, the increasing demands to also measure under harsh environmental conditions pave the way for non-invasive measurements and thus optical detection techniques. Here, we present the development of two optical detection systems using non-dispersive infrared absorption spectroscopy (NDIR). One system is intended for civilian use, capable of detecting both CO as well as CO2 in the range of 4–5 µm. Furthermore, restrictions regarding size and economic viability are put on this sensor so it can compete with existing sensors. For CO2, an estimated resolution of 444 ppm is achieved, which is competitive with established sensors on the market. For CO an estimated resolution of 1401 ppm was achieved, rendering it necessary to improve this sensor to be competitive with other available sensors. The second system is used in an exhaust system and is capable of detecting CO2 at 3.2 µm facing cross-sensitivity with H2O. A data analysis method is described to separate the CO2 and H2O signals, revealing a time resolution of 33 µs.

Flexible tactile pressure sensor arrays based on multiwalled carbon nanotubes (MWCNT) and polydimethylsiloxane (PDMS) are gaining importance, especially in the field of robotics because of the high demand for stable, flexible and sensitive sensors. Some existing concepts of pressure sensors based on nanocomposites exhibit complicated fabrication techniques and better sensitivity than the conventional pressure sensors. In this article, we propose a nanocomposite-based pressure sensor that exhibits a high sensitivity of 25 % N−1, starting with a minimum load range of 0–0.01 N and 46.8 % N−1 in the range of 0–1 N. The maximum pressure sensing range of the sensor is approximately 570 kPa. A concept of a 4×3 tactile sensor array, which could be integrated to robot fingers, is demonstrated. The high sensitivity of the pressure sensor enables precision grasping, with the ability to sense small objects with a size of 5 mm and a weight of 1 g. Another application of the pressure sensor is demonstrated as a gait analysis for humanoid robots. The pressure sensor is integrated under the foot of a humanoid robot to monitor and evaluate the gait of the robot, which provides insights for optimizing the robot's self-balancing algorithm in order to maintain the posture while walking.

Objective: Previous research has reported associations between Helicobacter pylori and hyperemesis gravidarum (hyperemesis). Whether the human gastrointestinal microbiota is associated with hyperemesis has not been studied. The aim of the present study was to explore gut microbiota among women with and without hyperemesis. In addition, we also studied the consequence of the absence or presence of H. pylori on the metagenomics of intestinal microbiota. Patients and Methods: Faecal samples were collected from immigrant pregnant women in Norway hospitalized due to hyperemesis (n=52) and pregnant women without hyperemesis (n=161). DNA extraction, 16S rRNA gene amplification and sequencing, and H. pylori PCR were conducted. Data on maternal age, parity, number of pregnancies, or patient history regarding hyperemesis was registered. Furthermore, information on country of birth and length of stay in Norway was also recorded. Additionally, use of antibiotics during the last 2 months before inclusion in the study was registered. Results: Results from the H. pylori specific PCR demonstrated a lower carriage rate among pregnant women without hyperemesis (23.5%) compared to the hyperemesis-positive group (26.9%). However, the difference between the two groups was not significant (p>0.05). Faeces from hyperemesis-negative women were comprised of the following groups of bacteria (N=9): Actinobacteria (2 groups), Bifidobacteriales, Bifidobacteriaeae, Bifidobacterium, Bulleidia, Clostridiacae, Clostridiae div, and Unclassified Clostridiaceae. A higher number of groups (N=20) was detected in faeces from hyperemesis patients (viz., Alcaligenacae, Bacterioidaceae, Bacterioides, Betaproteobacteria, Burkholderidales, Clostridia, Clostridiales other types, Firmicutes, Ocillospira other types, Parabacteroides, Porphyromonadaceae, Rikenellaceae, Rikenellaceae other types, Ruminococcacae, Ruminococcacae, Ruminococcaceae other types, Ruminococcus, Sutterella, unclassified Lachnospiraceae, and unclassified Rikenellaceae). Conclusions: In hyperemesis-positive women, gut microbiota displayed higher alpha diversity than hyperemesis-negative women (p=0.0015). Clostridiales were present in women with and without hyperemesis. However, more groups were observed in the hyperemesis group (viz., Bacteriodaceae, Bacteroides, Firmicutes, Clostridia and Betaproteobacteria).

Abstract Background The interpretation of previous studies on the association of physical activity and sedentary behaviour with psychological health is limited by the use of mostly self-reported physical activity and sedentary behaviour, and a focus on Western populations. We aimed to explore the association of self-reported and devise-based measures of physical activity and sedentary behaviour domains on psychological distress in an urban multi-ethnic Asian population. Methods From a population-based cross-sectional study of adults aged 18–79 years, data were used from an overall sample (n = 2653) with complete self-reported total physical activity/sedentary behaviour and domain-specific physical activity data, and a subsample (n = 703) with self-reported domain-specific sedentary behaviour and accelerometry data. Physical activity and sedentary behaviour data were collected using the Global Physical Activity Questionnaire (GPAQ), a domain-specific sedentary behaviour questionnaire and accelerometers. The Kessler Screening Scale (K6) and General Health Questionnaire (GHQ-12) were used to assess psychological distress. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals, adjusted for socio-demographic and lifestyle characteristics. Results The sample comprised 45.0% men (median age = 45.0 years). The prevalence of psychological distress based on the K6 and GHQ-12 was 8.4% and 21.7%, respectively. In the adjusted model, higher levels of self-reported moderate-to-vigorous physical activity (MVPA) were associated with significantly higher odds for K6 (OR = 1.47 [1.03–2.10]; p-trend = 0.03) but not GHQ-12 (OR = 0.97 [0.77–1.23]; p-trend = 0.79), when comparing the highest with the lowest tertile. Accelerometry-assessed MVPA was not significantly associated with K6 (p-trend = 0.50) nor GHQ-12 (p-trend = 0.74). The highest tertile of leisure-time physical activity, but not work- or transport-domain activity, was associated with less psychological distress using K6 (OR = 0.65 [0.43–0.97]; p-trend = 0.02) and GHQ-12 (OR = 0.72 [0.55–0.93]; p-trend = 0.01). Self-reported sedentary behaviour was not associated with K6 (p-trend = 0.90) and GHQ-12 (p-trend = 0.33). The highest tertile of accelerometry-assessed sedentary behaviour was associated with significantly higher odds for K6 (OR = 1.93 [1.00–3.75]; p-trend = 0.04), but not GHQ-12 (OR = 1.34 [0.86–2.08]; p-trend = 0.18). Conclusions Higher levels of leisure-time physical activity and lower levels of accelerometer-based sedentary behaviour were associated with lower psychological distress. This study underscores the importance of assessing accelerometer-based and domain-specific activity in relation to mental health, instead of solely focusing on total volume of activity.

Abstract Interactions of long non-coding RNAs (lncRNA) with proteins play important roles in the regulation of many cellular processes. PANDAR (Promotor of CDKN1A Antisense DNA damage Activated RNA) is a lncRNA that is transcribed in a p53-dependent manner from the CDKN1A promoter and is involved in the regulation of proliferation and senescence. Overexpression of PANDAR has been observed in several tumor species and correlated with a poor prognosis for patient survival rate. Depending on the cellular state, PANDAR is known to interact with proteins such as the nuclear transcription factor Y subunit A (NF-YA) and the scaffold attachment factor A (SAF-A). However, a comprehensive analysis of the PANDAR interactome was missing so far. Therefore, we applied peptide nucleic acid (PNA)-based pull-downs combined with quantitative mass spectrometry to identify new protein binding partners. We confirmed potential candidates like U2AF65 and PTBP1, known to be involved in RNA processing. Furthermore, we observed that overexpression of PANDAR leads to a reduced level of the short pro-apoptotic BCL-X splice variant (BCL-XS) which is regulated by PTBP1. Simultaneous overexpression of PTBP1 was able to rescue this effect. Overall, our data suggest a role for PANDAR in the regulation of splicing events via its interaction partner PTBP1.

Today, humans have a critical impact on the Earth system and vice versa, which can generate complex feedback processes between social and ecological dynamics. Integrating human behavior into formal Earth system models (ESMs), however, requires crucial modeling assumptions about actors and their goals, behavioral options, and decision rules, as well as modeling decisions regarding human social interactions and the aggregation of individuals' behavior. Here, we review existing modeling approaches and techniques from various disciplines and schools of thought dealing with human behavior at different levels of decision making. We demonstrate modelers' often vast degrees of freedom but also seek to make modelers aware of the often crucial consequences of seemingly innocent modeling assumptions. After discussing which socioeconomic units are potentially important for ESMs, we compare models of individual decision making that correspond to alternative behavioral theories and that make diverse modeling assumptions about individuals' preferences, beliefs, decision rules, and foresight. We review approaches to model social interaction, covering game theoretic frameworks, models of social influence, and network models. Finally, we discuss approaches to studying how the behavior of individuals, groups, and organizations can aggregate to complex collective phenomena, discussing agent-based, statistical, and representative-agent modeling and economic macro-dynamics. We illustrate the main ingredients of modeling techniques with examples from land-use dynamics as one of the main drivers of environmental change bridging local to global scales.

Changes in land-use systems in tropical regions, including deforestation, are a key challenge for global sustainability because of their huge impacts on green-house gas emissions, local climate and biodiversity. However, the dynamics of land-use and land-cover change in regions of frontier expansion such as the Brazilian Amazon are not yet well understood because of the complex interplay of ecological and socioeconomic drivers. In this paper, we combine Markov chain analysis and complex network methods to identify regimes of land-cover dynamics from land-cover maps (TerraClass) derived from high-resolution (30 m) satellite imagery. We estimate regional transition probabilities between different land-cover types and use clustering analysis and community detection algorithms on similarity networks to explore patterns of dominant land-cover transitions. We find that land-cover transition probabilities in the Brazilian Amazon are heterogeneous in space, and adjacent subregions tend to be assigned to the same clusters. When focusing on transitions from single land-cover types, we uncover patterns that reflect major regional differences in land-cover dynamics. Our method is able to summarize regional patterns and thus complements studies performed at the local scale.

Within a national funded Brazilian-German cooperation project ASHES, the thermal utilization of bagasse and other residuals from the sugar processing industry was examined. The characterization of the ashes was also performed but it is not in the focus of this paper. To determine the relevant combustion parameters, tests were carried out in a laboratory-scale, fixed bed reactor (KLEAA) at KIT-ITC. Subsequently, Fraunhofer UMSICHT carried out tests in continuously operated combustion plants with different plant sizes of 30 kW, 100 kW, and 440 kW. All relevant compositions were analyzed by CUTEC. The primary objective was to gain knowledge regarding the combustion and emission behavior of the fuels. These findings were used to identify optimization potentials at various points and elaborate concepts for their improvement. In the next steps of the project, optimization of these concepts will be the focus. In cooperation with the Brazilian project partners, several of them should be implemented into practice after the project.

The outlet glaciers to the embayment of the Larsen-B Ice Shelf started to accelerate soon after the ice shelf disintegrated in March 2002. We analyse high resolution radar images of the TerraSAR-X satellite, launched in June 2007, to map the motion of outlet glaciers in detail. The frontal velocities are used to estimate the calving fluxes for 2008/2009. As reference for pre-collapse conditions, when the glaciers were in balanced state, the ice fluxes through the same gates are computed using ice motion maps derived from interferometric data of the ERS-1/ERS-2 satellites in 1995 and 1999. Profiles of satellite laser altimetry from ICESat, crossing the terminus of several glaciers, indicate considerable glacier thinning between 2003 and 2007/2008. This is taken into account for defining the calving cross sections. The difference between the pre- and post-collapse fluxes provides an estimate on the mass imbalance. For the Larsen-B embayment the 2008 mass deficit is estimated at 4.34 ± 1.64 Gt a−1, significantly lower than previously published values. The ice flow acceleration follows a similar pattern on the various glaciers, gradually decreasing in magnitude with distance upstream from the calving front. This suggests stress perturbation at the glacier front being the main factor for acceleration. So far there are no signs of slow-down indicating that dynamic thinning and frontal retreat will go on.

This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV/c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles.

Precision experiments, such as the search for electric dipole moments of charged particles using storage rings, demand for an understanding of the spin dynamics with unprecedented accuracy. The ultimate aim is to measure the electric dipole moments with a sensitivity up to 15 orders in magnitude better than the magnetic dipole moment of the stored particles. This formidable task requires an understanding of the background to the signal of the electric dipole from rotations of the spins in the spurious magnetic fields of a storage ring. One of the observables, especially sensitive to the imperfection magnetic fields in the ring is the angular orientation of stable spin axis. Up to now, the stable spin axis has never been determined experimentally, and in addition, the JEDI collaboration for the first time succeeded to quantify the background signals that stem from false rotations of the magnetic dipole moments in the horizontal and longitudinal imperfection magnetic fields of the storage ring. To this end, we developed a new method based on the spin tune response of a machine to artificially applied longitudinal magnetic fields. This novel technique, called spin tune mapping, emerges as a very powerful tool to probe the spin dynamics in storage rings. The technique was experimentally tested in 2014 using polarized deuterons stored in the cooler synchrotron COSY, and for the first time, the angular orientation of the stable spin axis at two different locations in the ring has been determined to an unprecedented accuracy of better than 2.8 μ rad.

The difference products (DP) of representational difference analyses (RDA) were used as hybridization probes on cDNA arrays. The effectivity of RDA products obtained with increasing driver/tester ratios (DP 1 = 100:1, DP 2 = 800:1 and DP 3 = 400000:1) to isolate differentially expressed genes was compared with the effectivity of conventional differential hybridizations. Pacreatic cancer and control tissues were used as a test system to isolate differentially expressed genes. The use of RDA products as hybridization probes showed two major advantages: (i) a reliable identification of true differential signals; and (ii) only one autoradiograph had to be analyzed, which eliminated the need for a laborious subtraction of signal intensities obtained with different cDNA probes. Increasing driver/tester ratios in iterative rounds of RDA delivered more specific results, though the total yield of differential clones was gradually reduced. In this situation, the intermediate RDA product DP 2 provided the best compromise.

We express a matrix version of the self-induced transparency (SIT) equations in the bidifferential calculus framework. An infinite family of exact solutions is then obtained by application of a general result that generates exact solutions from solutions of a linear system of arbitrary matrix size. A side result is a solution formula for the sine-Gordon equation.

Basic fibroblast growth factor (FGF-2) has been shown to enhance the survival and neurite extension of various types of neurons including spinal ganglion neurons. In addition, endogenous FGF-2 and FGF receptors are upregulated following peripheral nerve lesion in ganglia and at the lesion site. FGF-2 protein is expressed in different isoforms (18 kDa, 21 kDa, 23 kDa) and differentially regulated after nerve injury. In the rat we analyzed the regenerative capacity of the high molecular weight (HMW) FGF-2 isoforms (21/23 kDa) to support the regeneration of the axotomized adult sciatic nerve across long gaps. The nerve stumps were inserted into the opposite ends of a silicone chamber resulting in an interstump gap of 15 mm. Silicone tubes were filled with Matrigel or a mixture of Schwann cells (SC) and Matrigel. SC were prepared from newborn rats and transfected to overexpress HMW FGF-2. Four weeks after the operation procedure, channels were analyzed with regard to tissue cables bridging both nerve stumps and myelinated axons distal to the original proximal nerve stump. Peripheral nerves interposed with HMW Schwann cells displayed significantly enhanced nerve regeneration, with the greatest number of tissue cables containing myelinated axons and the highest number of myelinated axons. These results suggest that a cellular substrate together with a source of a trophic factor could be a promising tool to promote nerve regeneration and, therefore, become useful also for a clinical approach to repair long gaps.

Electro-optical detection of THz coherent synchrotron radiation is a nondestructive method for measuring subpicosecond electron bunches or subpicosecond substructures on otherwise longer electron bunches. With a new diagnostic setup at the Swiss Light Source, which combines an amplified Yb fiber laser and a suitable GaP crystal, we demonstrate sampling as well as spectrally resolved single-shot measurements of sliced electron bunches containing as little as a few pC of charge. The single-shot measurements not only allow for a precise electric field characterization but also for a detailed analysis of the timing jitter between the electron bunch and the synchronized Yb fiber laser. The measurements of subsequent turns in the storage ring show distinct deviations from the simulations and we find strong indications that this discrepancy is caused by radiation loss through coherent synchrotron radiation itself, which is not included in many of today’s simulation codes.

Experimental results concerning the dependence of the sheet resistivity and the noise coefficient on the grain size and the volume fraction, respectively, of the metallic-like component in Bi2Ru2O7-based thick-film resistors are presented. The results are compared with current models for the electrical conduction mechanism in these resistors.

No abstract available.

No abstract available.

No abstract available.

Auf Empfehlung der UNESCO sollen während der Internationalen Hydrologischen Dekade (IHD) sämtliche Süßwasservorkommen der Welt erfaßt werden. Als Beitrag zu diesen Bemühungen wird gegenwärtig am Geographischen Institut der ETHZ ein Schweizerisches Gletscherinventar aufgestellt. Die Arbeiten am Inventar werfen einige Probleme auf, die im folgenden dargestellt werden. Das gesammelte Datenmaterial bildet Grundlage für ein Forschungsprojekt, welches weitere Erkenntnisse über die Beziehung zwischen Gletscher und Klima liefern soll.

No abstract available.

No abstract available.

The heterogeneous structure of TFR's results in high resistivities and high current noise. Accepting models of conduction in TFR's, according to which the resistivity is determined by a resistance independent of bulk-resistivity of a metallic-like component, it will be shown, that R□ and Ceff*(describing current noise behaviour) increase with d and d3, respectively, when d is the grain size. On the other hand, both quantities depend on the volume fraction of the metallic component in the same manner. This leads to the conclusion, that a general dependence in the form Ceff*= f(R□) cannot exist.