FFM noise characterization of phase-locked impatt diode oscillators

A technique has been developed to carefully measure the power-noise characteristics of IMPATT oscillators. The objective being to determine their suitability as power amplifiers in the transmitters of frequency modulated radio-relay systems

Der Adhäsions-GPCR CD97/ADGRE5 interagiert in adherens junctions mit β-catenin

CD97 ist ein G protein-coupled receptor der zu der Gruppe der Adhäsions-GPCRs zuzuordnen ist. CD97 ist im normalen humanen Darmepithel in lateralen Zellkontakten lokalisiert. In transgenen Mäusen, die CD97 selektiv in normalen intestinalen Epithelzellen überexprimieren, werden die adherens junctions durch Stabilisierung des nicht-phosphorylierten membran-gebundenen β-catenins verstärkt. Neben der Epithelzellverband-stabilisierenden Funktion von β-catenin in adherens junctions spielt β-catenin im Zellkern als Aktivator von Transkriptionsfaktoren eine entscheidende Rolle in der kolorektalen Karzinogenese. Diese unterschiedliche zelluläre Verteilung wird über den kanonischen Wnt-Signalweg reguliert. CD97 wird in kolorektalen Karzinomen hochreguliert. Steinert et al. beschrieben, dass insbesondere sogenannte scattered Tumorzellen an der Invasionsfront des kolorektalen Karzinoms CD97 im Vergleich zu Zellen im Tumorzentrum höher exprimieren. Dieses Phänomen geht mit einem höheren Tumorstadium und verstärkter Lymphgefäßinvasion einher. In diesen Zellen wird β-catenin verstärkt im Zytoplasma und im Zellkern exprimiert. Die histologische Lokalisation von CD97 im kolorektalen Normal- und Karzinomgewebe ließ zunächst vermuten, dass CD97 ein direktes β-catenin/Tcf-Zielgen im fehlregulierten Wnt-Signalweg ist. Es konnte jedoch gezeigt werden, dass CD97 kein Zielgen des kanonischen Wnt-Signalweges ist. In dieser Arbeit wird zum ersten Mal eine immunhistochemische Studie durchgeführt, die die Lokalisation von CD97 und β-catenin in normalem und malignem kolorektalem Gewebe parallel vergleichend analysiert. Bisher konnte CD97 nur im Kryostat-Schnitt immunhistochemisch dargestellt werden. Die immunhistochemische Darstellung der nukleären Expression von β-catenin ist jedoch nur in Paraffin-eingebetteten Geweben möglich. Somit etablierten wir erstmals eine immunhistochemische Färbemethode, die es erlaubt CD97 in Paraffin-eingebetteten humanen kolorektalen Geweben darzustellen. CD97 wird in allen Schnitten des kolorektalen Normalgewebes exprimiert. Sowohl CD97 als auch β-catenin sind dabei vorwiegend in den lateralen Zellkontakten aber auch im Zytoplasma der Zellen lokalisiert. Die Färbescores von CD97 und β-catenin in den lateralen Zellkontakten der normalen Enterozyten korrelieren signifikant miteinander. In kolorektalen Karzinomen verschwinden dann beide Moleküle simultan aus diesen lateralen Zellkontakten. Während β-catenin daraufhin im Zytoplasma und den Zellkernen der Karzinomzellen erscheint, ist die neu auftretende verstärkte Expression von CD97 auf das Zytoplasma der Karzinomzellen beschränkt. Dieses simultane Auftreten von CD97 im Zytoplasma und von β-catenin im Zellkern maligner kolorektaler Zellen korreliert mit dem Auftreten von scattered Tumorzellen. Die scattered Tumorzellen, auch als tumor buds bezeichnet, besitzen hypo-proliferative und apoptotische Eigenschaften. Diese scattered Tumorzellen an der Invasionsfront der kolorektalen Karzinome unseres Kollektivs exprimieren CD97 jedoch nicht stärker als Zellen im Karzinomzentrum. β-catenin hingegen wird in diesen scattered Tumorzellen vermehrt im Zytoplasma und in den Zellkernen exprimiert. Die Unterschiede der Färbeergebnisse im Vergleich zur Arbeit von Steinert et al. sind zum einen auf die Verwendung von Paraffin- statt Kryostat-Schnitten in unserer Studie und zum anderen auf die Nutzung verschiedener Antikörper gegen CD97, die unterschiedliche Epitope erkennen, zurückzuführen. Wir konnten einen Expressionsgradienten von CD97 entlang der Krypt-Villus-Achse, mit starker Expression im Kryptenbereich und schwächerer Expression in apikalen Bereichen, zeigen. Passend dazu wird nicht-phosphoryliertes membrangebundenes β-catenin in Kryptengrund-nahen Enterozyten stärker exprimiert. Dies ist ein weiterer Hinweis auf eine wahrscheinliche Interaktion von CD97 und nicht-phosphoryliertem membrangebundenem β-catenin. Ebenfalls passend zum hier gezeigten Expressionsgradienten von CD97 entlang der Krypt-Villus-Achse und der Regeneration der Enterozyten aus Kryptengrund-nahen undifferenzierten intestinalen Stammzellen konnte zuletzt gezeigt werden, dass der Vorgang der Apoptose durch CD97 inhibiert wird. Hier konnten wir nachweisen, dass in weiter luminal gelegenen Enterozyten die Expression von CD97 abnimmt. Diese Beobachtung harmoniert mit der Tatsache, dass apoptotische Zelluntergänge, im Sinne der Homöostase der intestinalen Selbsterneuerung, in diesen Enterozyten zunehmen. Dieses apoptotische Verhalten von CD97 könnte eine wichtige Rolle beim Überleben von Tumorzellen spielen. Kürzlich konnten wir in unserer Arbeitsgruppe zeigen, dass CD97 und β-catenin in den lateralen Zell-Zellkontakten miteinander interagieren. Passend dazu ko-immunpräzipitiert CD97 β-catenin in DLD-1-Zellen und transgenen (Tg-villin-CD97) Zellen und umgekehrt. Obwohl sich wie hier gezeigt die Expression von CD97 und β-catenin in den lateralen Zell-Zellkontakten simultan vermindert und es sich gleichzeitig eine parallele Zunahme der Expression von CD97 und β-catenin im Zytoplasma zeigt, kommt es zu keiner nachweisbaren Interaktion beider Moleküle im Zytoplasma. Passend dazu konnte auch nur in den lateralen Zellkontakten eine Kolokalisation beider Moleküle in der Immunfluoreszens gezeigt werden. Es konnte ebenfalls gezeigt werden, dass CD97 weder die Lokalisation noch die Expression von β-catenin beeinflusst. Wie beschrieben stabilisiert CD97 die lateralen Zell-Zellkontakte im normalen Epithelgewebe. Im Gegensatz dazu steht die Funktion von CD97 in malignen Geweben. Die Expression von CD97 korreliert mit dem Vermögen von kolorektalen Tumorzelllinien zur Serum-induzierten Migration und Invasion. Die Serumkomponente Lysophosphatidsäure (LPS) induziert Zellmigration durch eine Dämpfung der LPS-Rezeptor Signaltransduktion über Gα12/13 und RhoA auf das Zytoskelett durch eine Interaktion mit CD97. Für diese durch CD97 verstärkte Zellmigration ist das vollständige CD97-Molekül notwendig. Wie unlängst gezeigt, verhindert die Verkürzung des CTF von CD97 ebenfalls die Interaktion von CD97 und β-catenin. Noch ist unklar, ob die beiden Funktionen von CD97, Zelladhäsion und Regulation der Migration von Tumorzellen, miteinander im Zusammenhang stehen. Die Reduktion von CD97 in den lateralen Zell-Zellkontakten führt zum Auftreten von CD97 im Zytoplasma. Interessanterweise konnte zuletzt in unserer Arbeitsgruppe gezeigt werden, dass CD97 nach Zerstörung dieser Zell-Zellkontakte schneller im Zytoplasma erscheint als β-catenin. Dieser Fakt spricht mehr für eine Translokation als für eine Akkumulation bzw. Hinderung des Transports von CD97 zur Zellmembran in Tumorzellen. Es konnte gezeigt werden, dass nach dem Erscheinen von CD97 im Zytoplasma die Kolokalisation und somit auch die Interaktion mit β-catenin nicht mehr nachweisbar ist. Somit stimuliert CD97 nicht die β-catenin-abhängige TCF-vermittelte Aktivität von Transkriptionsfaktoren und es kommt nicht zur Aktivierung von Genen, die Proteine kodieren, welche u.a. die kolorektale Karzinogenese stimulieren. Zusammenfassend lässt sich sagen, dass CD97 ein multifunktionales Protein ist, dass über eine Interaktion mit β-catenin in adherens junctions in normalen Epithelzellen die Zell-Zelladhäsion reguliert und andererseits über eine Interaktion mit dem LPS-Rezeptor eine wichtige Rolle in Signaltransduktionswegen in Karzinomzellen spielt

Fatigue and progression of corpus callosum atrophy in multiple sclerosis

Fatigue is one of the most disabling symptoms in multiple sclerosis (MS) patients. There is no or only weak correlation between conventional magnetic resonance imaging (MRI) parameters and level of fatigue. The aim of this study was to investigate the relationship between progression of corpus callosum (CC) atrophy and fatigue in MS patients. This was a cohort study in 70 patients with relapsing form of MS (RRMS) and serial MRIs over a mean follow-up of 4.8years [67% female, mean age 42±11years, mean disease duration 9.7±7.6years, mean Expanded Disability Status Scale (EDSS) 2.8±1.6]. Fatigue was assessed by the Fatigue Severity Scale (FSS). CC size was measured with the CC index (CCI). In total, 40% of the patients suffered from fatigue (mean FSS score 5.3±1.1) and 60% patients had no fatigue (mean FSS score of 2.1±1). Patients with fatigue had higher EDSS scores (p=0.01) and CC atrophy was more pronounced in patients with fatigue (−21.8 vs. −12.1%, p=0.005). FSS correlated with CCI change over time (r=−0.33; p=0.009) and EDSS (p=0.008; r=0.361). The association between annualized CCI change and FSS was independent from EDSS, disease duration, gender and age in a multivariate linear regression analysis (p<0.001). Progression of CC atrophy may play a role in the evolution of MS-related fatigu

Corpus callosum index and long-term disability in multiple sclerosis patients

Prediction of long-term disability in patients with multiple sclerosis (MS) is essential. Magnetic resonance imaging (MRI) measurement of brain volume may be of predictive value but sophisticated MRI techniques are often inaccessible in clinical practice. The corpus callosum index (CCI) is a normalized measurement that reflects changes of brain volume. We investigated medical records and 533 MRI scans at diagnosis and during clinical follow-up of 169 MS patients (mean age 42±11years, 86% relapsing-remitting MS, time since first relapse 11±9years). CCI at diagnosis was 0.345±0.04 and correlated with duration of disease (p=0.002; r=−0.234) and expanded disability status scale (EDSS) score at diagnosis (r=−0.428; p<0.001). Linear regression analyses identified age, duration of disease, relapse rate and EDSS at diagnosis as independent predictors for disability after mean of 7.1years (Nagelkerkes' R:0.56). Annual CCI decrease was 0.01±0.02 (annual tissue loss: 1.3%). In secondary progressive MS patients, CCI decrease was double compared to that in relapsing-remitting MS patients (p=0.04). There was a trend of greater CCI decrease in untreated patients compared to those who received disease modifying drugs (p=0.2). CCI is an easy to use MRI marker for estimating brain atrophy in patients with MS. Brain atrophy as measured with CCI was associated with disability progression but it was not an independent predictor of long-term disabilit

Bedrock erosion by root fracture and tree throw: A coupled biogeomorphic model to explore the humped soil production function and the persistence of hillslope soils

In 1877, G. K. Gilbert reasoned that bedrock erosion is maximized under an intermediate soil thickness and declines as soils become thinner or thicker. Subsequent analyses of this “humped” functional relationship proposed that thin soils are unstable and that perturbations in soil thickness would lead to runaway thinning or thickening of the soil. To explore this issue, we developed a numerical model that simulates the physical weathering of bedrock by root fracture and tree throw. The coupled biogeomorphic model combines data on conifer population dynamics, rootwad volumes, tree throw frequency, and soil creep from the Pacific Northwest (USA). Although not hardwired into the model, a humped relationship emerges between bedrock erosion and soil thickness. The magnitudes of the predicted bedrock erosion rates and their functional dependency on soil thickness are consistent with independent field measurements from a coniferous landscape in the region. Imposed perturbations of soil erosion during model runs demonstrate that where bedrock weathering is episodic and localized, hillslope soils do not exhibit runaway thinning or thickening. The pit-and-mound topography created by tree throw produces an uneven distribution of soil thicknesses across a hillslope; thus, although episodes of increased erosion can lead to temporary soil thinning and even the exposure of bedrock patches, local areas of thick soils remain. These soil patches provide habitat for trees and serve as nucleation points for renewed bedrock erosion and soil production. Model results also suggest that where tree throw is a dominant weathering process, the initial mantling of bedrock is not only a vertical process but also a lateral process: soil mounds created by tree throw flatten over time, spreading soil over bedrock surfaces

Age-Dependent Changes in the Proteome Following Complete Spinal Cord Transection in a Postnatal South American Opossum (Monodelphis domestica)

Recovery from severe spinal injury in adults is limited, compared to immature animals who demonstrate some capacity for repair. Using laboratory opossums (Monodelphis domestica), the aim was to compare proteomic responses to injury at two ages: one when there is axonal growth across the lesion and substantial behavioural recovery and one when no axonal growth occurs. Anaesthetized pups at postnatal day (P) 7 or P28 were subjected to complete transection of the spinal cord at thoracic level T10. Cords were collected 1 or 7 days after injury and from age-matched controls. Proteins were separated based on isoelectric point and subunit molecular weight; those whose expression levels changed following injury were identified by densitometry and analysed by mass spectrometry. Fifty-six unique proteins were identified as differentially regulated in response to spinal transection at both ages combined. More than 50% were cytoplasmic and 70% belonged to families of proteins with characteristic binding properties. Proteins were assigned to groups by biological function including regulation (40%), metabolism (26%), inflammation (19%) and structure (15%). More changes were detected at one than seven days after injury at both ages. Seven identified proteins: 14-3-3 epsilon, 14-3-3 gamma, cofilin, alpha enolase, heart fatty acid binding protein (FABP3), brain fatty acid binding protein (FABP7) and ubiquitin demonstrated age-related differential expression and were analysed by qRT-PCR. Changes in mRNA levels for FABP3 at P7+1day and ubiquitin at P28+1day were statistically significant. Immunocytochemical staining showed differences in ubiquitin localization in younger compared to older cords and an increase in oligodendrocyte and neuroglia immunostaining following injury at P28. Western blot analysis supported proteomic results for ubiquitin and 14-3-3 proteins. Data obtained at the two ages demonstrated changes in response to injury, compared to controls, that were different for different functional protein classes. Some may provide targets for novel drug or gene therapies

Cognition-enabled robotic wiping: Representation, planning, execution, and interpretation

Advanced cognitive capabilities enable humans to solve even complex tasks by representing and processing internal models of manipulation actions and their effects. Consequently, humans are able to plan the effect of their motions before execution and validate the performance afterwards. In this work, we derive an analog approach for robotic wiping actions which are fundamental for some of the most frequent household chores including vacuuming the floor, sweeping dust, and cleaning windows. We describe wiping actions and their effects based on a qualitative particle distribution model. This representation enables a robot to plan goal-oriented wiping motions for the prototypical wiping actions of absorbing, collecting and skimming. The particle representation is utilized to simulate the task outcome before execution and infer the real performance afterwards based on haptic perception. This way, the robot is able to estimate the task performance and schedule additional motions if necessary. We evaluate our methods in simulated scenarios, as well as in real experiments with the humanoid service robot Rollin’ Justin

Quantification of methane emissions in Hamburg using a network of FTIR spectrometers and an inverse modeling approach

Methane (CH4) is a potent greenhouse gas, and anthropogenic CH4 emissions contribute significantly to global warming. In this study, the CH4 emissions of the second most populated city in Germany, Hamburg, were quantified with measurements from four solar-viewing Fourier transform infrared (FTIR) spectrometers, mobile in situ measurements, and an inversion framework. For source type attribution, an isotope ratio mass spectrometer was deployed in the city. The urban district hosts an extensive industrial and port area in the south as well as a large conglomerate of residential areas north of the Elbe River. For emission modeling, the TNO GHGco (Netherlands Organisation for Applied Scientific Research greenhouse gas and co-emitted species emission database) inventory was used as a prior for the inversion. In order to improve the inventory, two approaches were followed: (1) the addition of a large natural CH4 source, the Elbe River, which was previously not included in the inventory, and (2) mobile measurements were carried out to update the spatial distribution of emissions in the TNO GHGco gridded inventory and derive two updated versions of the inventory. The addition of the river emissions improved model performance, whereas the correction of the spatial distribution with mobile measurements did not have a significant effect on the total emission estimates for the campaign period. A comparison of the updated inventories with emission estimates from a Gaussian plume model (GPM) showed that the updated versions of the inventory match the GPM emissions estimates well in several cases, revealing the potential of mobile measurements to update the spatial distribution of emission inventories. The mobile measurement survey also revealed a large and, at the time of the study, unknown point source of thermogenic origin with a magnitude of 7.9 ± 5.3 kg h-1 located in a refinery. The isotopic measurements show strong indications that there is a large biogenic CH4 source in Hamburg that produced repeated enhancements of over 1 ppm which correlated with the rising tide of the river estuary. The CH4 emissions (anthropogenic and natural) of the city of Hamburg were quantified as 1600 ± 920 kg h-1, 900 ± 510 kg h-1 of which is of anthropogenic origin. This study reveals that mobile street-level measurements may miss the majority of total methane emissions, potentially due to sources located within buildings, including stoves and boilers operating on natural gas. Similarly, the CH4 enhancements recorded during the mobile survey from large-area sources, such as the Alster lakes, were too small to generate GPM emission estimates with confidence, but they could nevertheless influence the emission estimates based on total column measurements

Observational constraints on methane emissions from Polish coal mines using a ground-based remote sensing network

Given its abundant coal mining activities, the Upper Silesian Coal Basin (USCB) in southern Poland is one of the largest sources of anthropogenic methane (CH$_{4}$) emissions in Europe. Here, we report on CH$_{4}$emission estimates for coal mine ventilation facilities in the USCB. Our estimates are driven by pairwise upwind–downwind observations of the column-average dry-air mole fractions of CH$_{4}$ (XCH$_{4}$) by a network of four portable, ground-based, sun-viewing Fourier transform spectrometers of the type EM27/SUN operated during the CoMet campaign in May–June 2018. The EM27/SUN instruments were deployed in the four cardinal directions around the USCB approximately 50 km from the center of the basin. We report on six case studies for which we inferred emissions by evaluating the mismatch between the observed downwind enhancements and simulations based on trajectory calculations releasing particles out of the ventilation shafts using the Lagrangian particle dispersion model FLEXPART. The latter was driven by wind fields calculated by WRF (Weather Research and Forecasting model) under assimilation of vertical wind profile measurements of three co-deployed wind lidars. For emission estimation, we use a Phillips–Tikhonov regularization scheme with the L-curve criterion. Diagnosed by the emissions averaging kernels, we find that, depending on the catchment area of the downwind measurements, our ad hoc network can resolve individual facilities or groups of ventilation facilities but that inspecting the emissions averaging kernels is essential to detect correlated estimates. Generally, our instantaneous emission estimates range between 80 and 133 kt CH$_{4}$ a$^{-1}$ for the southeastern part of the USCB and between 414 and 790 kt CH$_{4}$a$^{-1}$ for various larger parts of the basin, suggesting higher emissions than expected from the annual emissions reported by the E-PRTR (European Pollutant Release and Transfer Register). Uncertainties range between 23 % and 36 %, dominated by the error contribution from uncertain wind fields

GEMINI 3D spectroscopy of BAL+IR+Fe II QSOs: II. IRAS 04505-2958 an explosive QSO with hypershell and a new scenario for galaxy formation and galaxy end

From a study of BAL + IR + Fe II QSOs (using deep Gemini GMOS-IFU spectroscopy) new results are presented: for IRAS 04505-2958. Specifically, we have studied in detail the out flow (OF) process and their associated structures, mainly at two large galactic scales: (i) two blobs/shells (S1, S2) at radius r = 1.1 and 2.2 kpc; and (ii) an external hypergiant shell (S3) at r = 11 kpc. In addition, the presence of two very extended hypergiant shells (S4, S5) at r = 80 kpc is discussed. From this GMOS study the following main results were obtained: (i) For the external hypergiant shell S3 the kinematics GMOS maps of the ionized gas show very similar features to those observed for the prototype of exploding external supergiant shell: in NGC 5514. (ii) The main knots K1, K2 and K3 -of this hypergiant shell S3- show a stellar population and emission line ratios associated with the presence of a starburst + OF/shocks. (iii) The internal shells S1 and S2 show structures, OF components and properties very similar to those detected in the nuclear shells of Mrk 231. (iv) The shells S1+S2 and S3 are aligned at PA = 131: i.e. suggesting that the OF process is in the blow-out phase with bipolar structure. In addition, the shells S4 and S5 (at 80-100 kpc scale) are aligned at PA = 40, i.e.: a bipolar OF perpendicular to the internal OF. Finally, the generation of UHE cosmic rays and neutrino/ dark-matter -associated with HyNe in BAL + IR + Fe II QSOs- is discussed.Comment: Submitted MNRAS, 81 pages, 25 Figure