A monolithic HEMT-amplifier with feedback in coplanar waveguide technology

A monolithic integrated wide-band amplifier is presented, which consists of two 0.3 μm HEMT-stages in GaAs/GaAlAs-Technology. The main signal path consists of a coplanar waveguide, which interfaces conveniently to the HEMT-cells. A feedback circuit with R, L and C connects gate and drain. To close the feedback loop small scale microstrip lines were combined with CPW /1, 2, 4/. Matching is done with a LC circuit at the gate and a combination of transmission line and capacitor at the drain. In addition there are some other passive elements for biasing, which reduce external components to a minimum. All element models were checked with measured data and placed into a CAD-library for easy use in the design process

Molecular Characterization of Pneumococcal Isolates from Pets and Laboratory Animals

was isolated from nose, lung and respiratory tract, eye, ear and other sites. over a period of up to 22 weeks was shown for four mastomys. Forty-one animals showed disease symptoms. Pneumococcal isolates were characterized by optochin sensitivity, bile solubility, DNA hybridization, pneumolysin PCR, serotyping and multilocus sequence typing. Eighteen of the 32 mastomys isolates (56%) were optochin resistant, all other isolates were optochin susceptible. All mastomys isolates were serotype 14, all guinea pig isolates serotype 19F, all horse isolates serotype 3. Rats had serotypes 14 or 19A, mice 33A or 33F. Dolphins had serotype 23F, the gorilla serotype 14. Cats and dogs had many different serotypes. Four isolates were resistant to macrolides, three isolates also to clindamycin and tetracyclin. Mastomys isolates were sequence type (ST) 15 (serotype 14), an ST/serotype combination commonly found in human isolates. Cats, dogs, pet rats, gorilla and dolphins showed various human ST/serotype combinations. Lab rats and lab mice showed single locus variants (SLV) of human STs, in human ST/serotype combinations. All guinea pig isolates showed the same completely new combination of known alleles. The horse isolates showed an unknown allele combination and three new alleles.The isolates found in mastomys, mice, rats, cats, dogs, gorilla and dolphins are most likely identical to human pneumococcal isolates. Isolates from guinea pigs and horses appear to be specialized clones for these animals. Our data redraw attention to the fact that pneumococci are not strictly human pathogens. Pet animals that live in close contact to humans, especially children, can be infected by human isolates and also carriage of even resistant isolates is a realistic possibility

Pandemia de Influenza A (N1H1): O Que Aprender com Ela?

Influenza pandemics are natural events that occur periodically. The pandemic’s current agent, Influenza virus A (H1N1) was first identified in Mexico in April 2009, spread rapidly and has caused deaths mainly among young adults. The objective of this manuscript is to present the biological aspects involved in the outbreak of this pandemic, as well as population-control strategies for pandemic influenza. In addition to the population mitigation measures, whose efficacy has been described by theoretical models, today we also have drugs with efficacy valued in some patient groups. These drugs reduce moderately the duration and severity of symptoms, as long as they are started early. This pandemic, with a large number of cases, but caused by a virus of low lethality, could be managed preferably in Units of Primary Health Care, that would treat the wild cases and forward the severe ones to the hospitals. However, what occurred in numerous cities was the burden on emergency care with triage situations, forcing managers to improvise field hospitals, tents and containers to house the extra work in services that were already at the limit of physical infrastructure and human resources. Pandemic Influenza exposed the fragility of our network of primary care and lack of ICU beds.Pandemias de gripe são eventos naturais que ocorrem periodicamente. O agente da pandemia atual, o vírus Influenza A (H1N1), foi identificado primeiramente no México em abril de 2009, disseminou-se rapidamente e tem causado óbitos principalmente entre adultos jovens. O objetivo deste manuscrito é apresentar os aspectos biológicos envolvidos na eclosão desta pandemia, bem como as estratégias de contenção populacional da pandemia de Influenza. Além das medidas populacionais, cuja eficácia tem sido descrita através de modelos teóricos, atualmente também dispomos de medicamentos com eficácia avaliada em alguns grupos de pacientes. Estes medicamentos reduzem moderadamente o tempo de duração e a gravidade dos sintomas, desde que iniciados precocemente. Esta pandemia, com um grande número de casos, mas causada por um vírus de baixa letalidade, poderia ser manejada preferentemente em Unidades de Atenção Primária à Saúde, que tratariam os casos leves e encaminhariam os graves aos hospitais. Contudo, o que ocorreu em inúmeras cidades foi a sobrecarga das emergências com situações de triagem, forçando os gestores a improvisar hospitais de campanha, containeres e tendas para abrigar o trabalho extra em serviços que já operavam no limite de estrutura física e de recursos humanos. A pandemia de Influenza expôs a fragilidade da nossa rede de atenção básica e a falta de leitos de UTI

Miniaturized Laser Altimeter for Small Satellite Applications

Laser Altimetry is a powerful tool to create absolutely calibrated digital terrain maps of planetary surfaces, to analyze their surface geology, and to get insight into the interior structure of planetary bodies by measuring tidal elevations and libration amplitudes and frequencies. The recent ESA missions BepiColombo and the Jupiter Icy Moons Explorer (JUICE) carry the first European laser altimeter instruments, i.e., the BepiColombo Laser Altimeter (BELA) and the Ganymede Laser Altimeter (GALA), the latter of which has a strong contribution from JAXA teams. The measurement principle of a laser altimeter is very simple. It is based on the time-of-flight measurement of an optical pulse. BELA, which is now on the way to Mercury orbit, applies a diode-laser pumped Nd:YAG laser sending pulses with an energy of 50 mJ, a width of about 5 ns, and a repetition rate of 10 Hz. Over typical ranging distances of 400 km to more than 1000 km, the BELA telescope collects pulses with a few hundred photons and a width of about 25 ns where the time of arrival gives the mean topographic altitude of the area illuminated by the 5 to 40 m diameter laser beam. The return pulse width further gives information on slope and roughness within this area. GALA is a similar instrument with 17 mJ pulse energy but 30 Hz repetition rate and was launched in April 2023 to enter the Jovian system after a eight-year cruise to fly-by at Europa and Callisto and finally orbit the Jovian moon Ganymede at an altitude of about 500 km above its icy surface. BELA and GALA are instruments that consume about 50 W and have a mass of close to 15 kg and 25 kg, respectively. The instrument dimensions are largely determined by the telescope diameter of about 30 cm. In order to enable the use of these instruments on small satellites the size, weight and power (SWaP) budgets need to be drastically reduced. This can be achieved by deriving the time-of-flight information from just a single return photon. The reduction factor of about 100 in the detected photon number can be shared by a reduction in laser energy and a reduction of telescope aperture diameter. Our aim is to reduce laser pulse energy from 17 mJ to 1 mJ and telescope diameter from 22 cm (for GALA) to 8 cm which implies in total a reduction factor about 130. GALA typically detects 700 photons per pulse at an altitude of 500 km which leads to about 5 photons to be analyzed per event by a single photon detection laser altimeter. The major challenges for a single photon detection laser altimeter are the reduction of the background photon rate by reducing the field-of-view of the telescope as well as better spectral filtering. We present first results from a conceptual experimental study of such a system designed for use on small satellites applying a newly developed detection scheme using a Single Photon Avalanche Diode (SPAD) and a diode-laser pumped microchip Nd:YAG laser emitting 1 mJ pulses with a pulse width of 1 ns. The reductions in dimension, mass, and power consumption of this instrument are discussed, and the scientific performance is simulated based on first experimental results. The feasibility of accommodating the instrument on the modular TUBiX20 microsatellite platform developed by Technische Universität Berlin is explored and the necessary requirements for attitude and orbit determination and control as well as SWaP budgets are derived

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

The Pierre Auger Observatory: Contributions to the 34th International Cosmic Ray Conference (ICRC 2015)

Contributions of the Pierre Auger Collaboration to the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The NetherlandsComment: 24 proceedings, the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands; will appear in PoS(ICRC2015

Development and analysis of the Soil Water Infiltration Global database.

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements (~76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type (~40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it