Treatment modalities of chronic plaque psoriasis have dramatically changed over the past ten years with a still continuing shift from inpatient to outpatient treatment. This development is mainly ...caused by outpatient availability of highly efficient and relatively well-tolerated systemic treatments, in particular BioLogicals. In addition, inpatient treatment is time- and cost-intense, conflicting with the actual burst of health expenses and with patient preferences. Nevertheless, inpatient treatment with dithranol and UV light still is a major mainstay of psoriasis treatment in Germany. The current study aims at comparing the total costs of inpatient treatment and outpatient follow-up to mere outpatient therapy with different modalities (topical treatment, phototherapy, classic systemic therapy or BioLogicals) over a period of 12 months. To this end, a retrospective cost-of-illness study was conducted on 120 patients treated at the University Medical Centre Mannheim between 2005 and 2006. Inpatient therapy caused significantly higher direct medical, indirect and total annual costs than outpatient treatment (13,042 € versus 2,984 €). Its strong influence on cost levels was confirmed by regression analysis, with total costs rising by 104.3% in case of inpatient treatment. Patients receiving BioLogicals produced the overall highest costs, whereas outpatient treatment with classic systemic antipsoriatic medications was less cost-intense than other alternatives.
We present an algorithm based on Self‐Organizing Maps (SOM) and k‐means clustering to recognize patterns in a continuous 12.5‐year tremor time series recorded at Whakaari/White Island volcano, New ...Zealand (hereafter referred to as Whakaari). The approach is extendable to a variety of volcanic settings through systematic tuning of the classifier. Hyperparameters are evaluated by statistical means, yielding a combination of “ideal” SOM parameters for the given data set. Extending from this, we applied a Kernel Density Estimation approach to automatically detect changes within the observed seismicity. We categorize the Whakaari seismic time series into regimes representing distinct volcano‐seismic states during recent unrest episodes at Whakaari (2012/2013, 2016, and 2019). There is a clear separation in classification results between background regimes and those representing elevated levels of unrest. Onset of unrest is detected by the classifier 6 weeks before the August 2012 eruption, and ca. 3.5 months before the December 2019 eruption, respectively. Regime changes are corroborated by changes in commonly monitored tremor proxies as well as with reported volcanic activity. The regimes are hypothesized to represent diverse mechanisms including: system pressurization and depressurization, degassing, and elevated surface activity. Labeling these regimes improves visualization of the 2012/2013 and 2019 unrest and eruptive episodes. The pre‐eruptive 2016 unrest showed a contrasting shape and nature of seismic regimes, suggesting differing onset and driving processes. The 2016 episode is proposed to result from rapid destabilization of the shallow hydrothermal system, while rising magmatic gases from new injections of magma better explain the 2012/2013 and 2019 episodes.
Plain Language Summary
Volcanoes produce different patterns and intensities of ground motions prior to eruptions, detectable in seismic signals. In this study, we investigate how the seismic signals recorded at Whakaari, New Zealand evolved between 2008 and 2020. We test an approach based on Artificial Intelligence (AI) to distinguish and classify seismic signals. Since classification results strongly depend on how the classifier is tuned, we investigate how it is best set up using test data sets. The classification provides a set of so‐called “seismic regimes,” which represent the relative dominance of different types of earthquake activity over time. To interpret how these regimes relate to volcanic processes, we compared them against reported volcanic activity. We show that the classifier distinguishes between normal and elevated seismic activity, possibly associated with increasing gas pressure within the volcano. This pressurization is a possible eruption precursor. We observe that the 2012/2013 and 2019 volcanic episodes at Whakaari have similar regime progression patterns, likely reflecting arrival of increased fluxes of magmatic gas at shallow depths. By contrast a shorter‐lived progression to an eruption in 2016 likely resulted from enhanced shallow trapping of background gas supply.
Key Points
Our algorithm automatically classifies tremor data from Whakaari/White Island using Self‐Organizing Maps
Statistical tests help us to select appropriate classification hyperparameters depending on input data
We attribute the detected changes in volcanic tremor to pressurization and depressurization of the volcanic system
In recent years, substantial efforts have been made to understand the implications of climate change on Antarctic krill,
Euphausia superba
, because of their pivotal role in the Southern Ocean food ...web and in biogeochemical cycling. Winter is one of the least studied seasons in Antarctica and we have limited understanding about the strategies Antarctic krill use to survive the winter. In particular, data on the winter physiology and condition of juvenile Antarctic krill are severely lacking. From May to September (the austral autumn-winter) of 2019, we maintained juvenile Antarctic krill in large (1,330 L) aquarium tanks at Palmer Station, Antarctica and, at monthly time intervals, measured their physiology and condition. Each tank served as a “food environment scenario”, representing possible food environments the krill may encounter during winter along the Western Antarctic Peninsula. We found that, unlike adults, juvenile krill maintain relatively high respiration rates through the winter and respond positively to increased food concentrations by increasing their ingestion rates. Unlike larval krill, juveniles use lipid stores accumulated during the summer and autumn to sustain themselves through periods of starvation in the winter. We used our empirically derived measurements of physiology and condition to estimate the energy budget and growth potential of juvenile krill during the winter. We found that, given their comparatively high respiration rates, small juvenile krill (20 mg dry weight) would need to encounter food at concentrations of ~ 0.15 mg C L
-1
daily to avoid loss of body carbon. Without sufficient lipid reserves, this value increases to ~ 0.54 mg C L
-1
, daily. The health of juvenile krill in the wintertime is dependent on their ability to accumulate lipid stores in the summer and autumn and to find sufficient food during the winter. Changes in food availability to Antarctic krill throughout the year may become problematic to juvenile krill in the future. Understanding the variability in the winter energy budget of juvenile Antarctic krill will allow us to improve population models that make assumptions on seasonal growth patterns.
The northwestern Antarctic Peninsula is an important spawning, recruitment, and overwintering ground for Antarctic krill. The region is warming rapidly, and the current impacts of climate and ...environmental variability on the reproductive cycle of krill remain unclear. Here, we examine the reproductive stage of female krill in the austral winter from 2012 to 2016 in relation to climate and environmental data to assess what factors influence the timing of reproductive development. We observed significant interannual variability in the degree of maturation in female krill, ranging from 48% of female krill measured at a station in 2016 to a maximum of 94% of female krill measured at a station in 2014. On average, across all five years, three-quarters of the female krill sampled were in the stage known as previtellogenesis, the point at which the onset of sexual maturity begins. The preceding spring, summer, and autumn Southern Annular Mode and the Multivariate El Niño Index explained most of the variance in the data and indicated a strong, preconditioning storm-related effect on environmental conditions leading up to winter, affecting krill maturation status at the end of the winter season. Results from our study can be used to improve krill population models that are necessary for the management of the krill fishery and for conservation at the northwestern Antarctic Peninsula.
The overwinter survival mechanisms of Antarctic krill,
Euphausia superba
, are poorly characterized, especially for juveniles. It has been suggested that juveniles adopt a mix of strategies ...characteristic of both larvae and adults. Like larvae, they may feed opportunistically throughout winter when food is available, and like adults they may be able to suppress their metabolism when food is scarce. In this study we look at the overwinter strategies of juvenile krill and how their reproductive development changes when energy input exceeds what is necessary for survival. We take a closer look at how the sexual maturation of juvenile krill progresses in response to different environmental conditions throughout the fall and winter. We exposed juvenile Antarctic krill to four different “food environment scenarios”, supplementing them with various diets from May to September 2019 that were representative of environmental conditions that they may encounter in different regions of the Western Antarctic Peninsula during autumn and winter. Each month, we measured the physiology and condition of the krill, and assessed the reproductive development of females. We found that when female juvenile krill have greater energy reserves than what is needed to survive the winter, they will begin to sexually mature. Further, when there are sufficient levels of the fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and 16:4 (
n-1
), krill are likely to be in a more reproductive advanced stage. However, when lipids, EPA, DHA and 16:4 (
n-1
) are depleted throughout the winter, juvenile female krill lose their ability to develop reproductively. We also found that sexual development is an energy intensive process that requires high respiration rates in juvenile krill. Furthermore, when juvenile females expend energy maturing, their physiological condition declines. This trade-off between early reproductive development and condition in juvenile female krill has important implications for individual health and population fecundity. Gaining a better understanding of the mechanisms behind juvenile krill winter survival strategies and their consequences will allow us to predict how future change at the western Antarctic Peninsula may affect krill population dynamics, especially in light of a warming climate.
Signal path optimization in software-defined radio systems Rykaczewski, P.; Pienkowski, D.; Circa, R. ...
IEEE transactions on microwave theory and techniques,
2005-March, 2005-03-00, 20050301, Letnik:
53, Številka:
3
Journal Article
Recenzirano
Growing requirements set upon communication transceivers lead to high sensitivity to nonidealities of analog components, especially in case of software-defined radio (SDR) systems. This paper deals ...with disturbances, mismatches, and the rejection of images that are caused by the front-end processing. A hybrid architecture comprehending advantages of homodyne and heterodyne receivers is proposed for an SDR system. Theoretical outcomes are discussed and backed by simulations. A fast Fourier transform (FFT)-based algorithm, the phase increment Kay algorithm, and two autocorrelation algorithms, i.e., Morelli-Mengali and Crozier-Moreland, used for frequency offset correction, are compared. The FFT algorithm turns out to be the best solution, both in terms of performance and ease of implementation. DC correction is then discussed and in-phase/quadrature imbalance compensation by means of a blind-source separation (BSS) algorithm and a hard-decision algorithm is performed. The latter algorithm displays implementation advantages, while BSS performs better.
Summary Background Preoperative chemoradiotherapy, total mesorectal excision surgery, and adjuvant chemotherapy with fluorouracil is the standard combined modality treatment for rectal cancer. With ...the aim of improving disease-free survival (DFS), this phase 3 study (CAO/ARO/AIO-04) integrated oxaliplatin into standard treatment. Methods This was a multicentre, open-label, randomised, phase 3 study in patients with histologically proven carcinoma of the rectum with clinically staged T3–4 or any node-positive disease. Between July 25, 2006, and Feb 26, 2010, patients were randomly assigned to two groups: a control group receiving standard fluorouracil-based combined modality treatment, consisting of preoperative radiotherapy of 50·4 Gy plus infusional fluorouracil (1000 mg/m2 days 1–5 and 29–33), followed by surgery and four cycles of bolus fluorouracil (500 mg/m2 days 1–5 and 29; fluorouracil group); and an experimental group receiving preoperative radiotherapy of 50·4 Gy plus infusional fluorouracil (250 mg/m2 days 1–14 and 22–35) and oxaliplatin (50 mg/m2 days 1, 8, 22, and 29), followed by surgery and eight cycles of adjuvant chemotherapy with oxaliplatin (100 mg/m2 days 1 and 15), leucovorin (400 mg/m2 days 1 and 15), and infusional fluorouracil (2400 mg/m2 days 1–2 and 15–16; fluorouracil plus oxaliplatin group). Randomisation was done with computer-generated block-randomisation codes stratified by centre, clinical T category (cT1–4 vs cT4), and clinical N category (cN0 vs cN1–2) without masking. DFS is the primary endpoint. Secondary endpoints, including toxicity, compliance, and histopathological response are reported here. Safety and compliance analyses included patients as treated, efficacy endpoints were analysed according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov , number NCT00349076. Findings Of the 1265 patients initially enrolled, 1236 were evaluable (613 in the fluorouracil plus oxaliplatin group and 623 in the fluorouracil group). Preoperative grade 3–4 toxic effects occurred in 140 (23%) of 606 patients who actually received fluorouracil and oxaliplatin during chemoradiotherapy and in 127 (20%) of 624 patients who actually received fluorouracil chemoradiotherapy. Grade 3–4 diarrhoea was more common in those who received fluorouracil and oxaliplatin during chemoradiotherapy than in those who received fluorouracil during chemoradiotherapy (73 patients 12% vs 52 patients 8%), as was grade 3–4 nausea or vomiting (23 4% vs nine 1%). 516 (85%) of the 606 patients who received fluorouracil and oxaliplatin-based chemoradiotherapy had the full dose of chemotherapy, and 571 (94%) had the full dose of radiotherapy; as did 495 (79%) and 601 (96%) of 624 patients who received fluorouracil-based chemoradiotherapy, respectively. A pathological complete response was achieved in 103 (17%) of 591 patients who underwent surgery in the fluorouracil and oxaliplatin group and in 81 (13%) of 606 patients who underwent surgery in the fluorouracil group (odds ratio 1·40, 95% CI 1·02–1·92; p=0·038). In the fluorouracil and oxaliplatin group, 352 (81%) of 435 patients who began adjuvant chemotherapy completed all cycles (with or without dose reduction), as did 386 (83%) of 463 patients in the fluorouracil group. Interpretation Inclusion of oxaliplatin into modified fluorouracil-based combined modality treatment was feasible and led to more patients achieving a pathological complete response than did standard treatment. Longer follow-up is needed to assess DFS. Funding German Cancer Aid (Deutsche Krebshilfe).
We report on the Delta *g-ray activity of the high-synchrotron-peaked BL Lacertae object Markarian 421 (Mrk 421) during the first 1.5 years of Fermi operation, from 2008 August 5 to 2010 March 12. We ...find that the Large Area Telescope (LAT) Delta *g-ray spectrum above 0.3 GeV can be well described by a power-law function with photon index Delta *G = 1.78 ? 0.02 and average photon flux F(> 0.3 GeV) = (7.23 ? 0.16) X 10--8 ph cm--2 s--1. Over this time period, the Fermi-LAT spectrum above 0.3 GeV was evaluated on seven-day-long time intervals, showing significant variations in the photon flux (up to a factor ~3 from the minimum to the maximum flux) but mild spectral variations. The variability amplitude at X-ray frequencies measured by RXTE/ASM and Swift/BAT is substantially larger than that in Delta *g-rays measured by Fermi-LAT, and these two energy ranges are not significantly correlated. We also present the first results from the 4.5 month long multifrequency campaign on Mrk 421, which included the VLBA, Swift, RXTE, MAGIC, the F-GAMMA, GASP-WEBT, and other collaborations and instruments that provided excellent temporal and energy coverage of the source throughout the entire campaign (2009 January 19 to 2009 June 1). During this campaign, Mrk 421 showed a low activity at all wavebands. The extensive multi-instrument (radio to TeV) data set provides an unprecedented, complete look at the quiescent spectral energy distribution (SED) for this source. The broadband SED was reproduced with a leptonic (one-zone synchrotron self-Compton) and a hadronic model (synchrotron proton blazar). Both frameworks are able to describe the average SED reasonably well, implying comparable jet powers but very different characteristics for the blazar emission site.
Context. Because of its proximity, Mrk 421 is one of the best sources on which to study the nature of BL Lac objects. Its proximity allows us to characterize its broadband spectral energy ...distribution (SED). Aims. The goal is to better understand the mechanisms responsible for the broadband emission and the temporal evolution of Mrk 421. These mechanisms may also apply to more distant blazars that cannot be studied with the same level of detail. Methods. A flare occurring in March 2010 was observed for 13 consecutive days (from MJD 55 265 to MJD 55 277) with unprecedented wavelength coverage from radio to very high energy (VHE; E> 100 GeV) γ-rays with MAGIC, VERITAS, Whipple, Fermi-LAT, MAXI, RXTE, Swift, GASP-WEBT, and several optical and radio telescopes. We modeled the day-scale SEDs with one-zone and two-zone synchrotron self-Compton (SSC) models, investigated the physical parameters, and evaluated whether the observed broadband SED variability can be associated with variations in the relativistic particle population. Results. The activity of Mrk 421 initially was high and then slowly decreased during the 13-day period. The flux variability was remarkable at the X-ray and VHE bands, but it was minor or not significant at the other bands. The variability in optical polarization was also minor. These observations revealed an almost linear correlation between the X-ray flux at the 2–10 keV band and the VHE γ-ray flux above 200 GeV, consistent with the γ-rays being produced by inverse-Compton scattering in the Klein-Nishina regime in the framework of SSC models. The one-zone SSC model can describe the SED of each day for the 13 consecutive days reasonably well, which once more shows the success of this standard theoretical scenario to describe the SEDs of VHE BL Lacs such as Mrk 421. This flaring activity is also very well described by a two-zone SSC model, where one zone is responsible for the quiescent emission, while the other smaller zone, which is spatially separated from the first, contributes to the daily variable emission occurring at X-rays and VHE γ-rays. The second blob is assumed to have a smaller volume and a narrow electron energy distribution with 3 × 104<γ< 6 × 105, where γ is the Lorentz factor of the electrons. Such a two-zone scenario would naturally lead to the correlated variability at the X-ray and VHE bands without variability at the optical/UV band, as well as to shorter timescales for the variability at the X-ray and VHE bands with respect to the variability at the other bands. Conclusions. Both the one-zone and the two-zone SSC models can describe the daily SEDs via the variation of only four or five model parameters, under the hypothesis that the variability is associated mostly with the underlying particle population. This shows that the particle acceleration and cooling mechanism that produces the radiating particles might be the main mechanism responsible for the broadband SED variations during the flaring episodes in blazars. The two-zone SSC model provides a better agreement with the observed SED at the narrow peaks of the low- and high-energy bumps during the highest activity, although the reported one-zone SSC model could be further improved by varying the parameters related to the emitting region itself (δ, B and R), in addition to the parameters related to the particle population.
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