Context-Dependent Acoustic Modeling without Explicit Phone Clustering

Phoneme-based acoustic modeling of large vocabulary automatic speech recognition takes advantage of phoneme context. The large number of context-dependent (CD) phonemes and their highly varying statistics require tying or smoothing to enable robust training. Usually, Classification and Regression Trees are used for phonetic clustering, which is standard in Hidden Markov Model (HMM)-based systems. However, this solution introduces a secondary training objective and does not allow for end-to-end training. In this work, we address a direct phonetic context modeling for the hybrid Deep Neural Network (DNN)/HMM, that does not build on any phone clustering algorithm for the determination of the HMM state inventory. By performing different decompositions of the joint probability of the center phoneme state and its left and right contexts, we obtain a factorized network consisting of different components, trained jointly. Moreover, the representation of the phonetic context for the network relies on phoneme embeddings. The recognition accuracy of our proposed models on the Switchboard task is comparable and outperforms slightly the hybrid model using the standard state-tying decision trees.Comment: Submitted to Interspeech 202

Regulierung der Doldenwelke im ökologischen Holunderanbau

Ziel des Projektes war es, Möglichkeiten zur Regulierung der Doldenwelke beim Schwarzen Holunder (Sambucus nigra) zu erarbeiten. Dazu wurde zunächst das zeitliche Auftreten der Pathogene erfasst sowie die Erreger bestimmt. In den vier in Nord- und Westdeutschland untersuchten Holunderanlagen wurde die Doldenwelke überwiegend durch Colletotrichum acutatum verursacht. Andere pilzliche Welkeerreger (wie Fusarium sp., Phoma sp.) spielten in den drei Jahren vergleichsweise nur eine untergeordnete Rolle. Vor allem ab Farbumschlag der Beeren stieg der Befall drastisch an. Untersuchungen zur Überdauerung von Colletotrichum acutatum in einer Befallsanlage haben ergeben, dass der Erreger im Dezember an alten Früchten und Fruchtstielen nachzuweisen war. Bei Probenahme im März und April konnte er an den Knospen zahlreicher einjähriger Triebe (= Fruchtholz für die bevorstehende Saison) – bevorzugt im apikalen Bereich - gefunden werden. Ebenso trat er auf dem nicht verrotteten Stielgerüst von auf dem Boden liegenden Fruchtdolden des Vorjahres und auf am Baum verbliebenen Zapfen vorjähriger Tragruten auf. In den Versuchsjahren 2007 bis 2009 wurden zahlreiche dem ökologischen Anbau zur Verfügung stehende Präparate in Freilandversuchen auf ihre Wirkung gegenüber der Holunderdoldenwelke getestet. Da bis dahin wenig erfolgreiche Ergebnisse erzielt werden konnten, wurden in den Folgejahren eine Fülle von weiteren Präparaten in Diffusionstests auf PDA-Nährmedium getestet und darauf basierend weitere Freilandversuche angelegt. Keines der Produkte konnte im Freiland eine zufrieden stellende Wirkung erzielen. Präparate auf Kupfer- oder Schwefelbasis, Bicarbonate oder Mykoparasit-Präparate wie Polyversum, die in Jahren mit schwachem Befall gute Wirkansätze zeigten, konnten in Jahren mit starkem Befall keinen Erfolg mehr verzeichnen. Da die Ausbreitung und vermutlich auch die Infektion der Dolden mit Colletotrichum acutatum mit einem feuchten Mikroklima zusammen hängt, wurden in der Saison 2010 und 2011 Teile einer Holunderanlage überdacht, um ein trockenes Mikroklima im Baum zu schaffen. Sehr deutliche Ergebnisse zeigt eine Überdachung von der Blüte bis zur Ernte. Hier wird der Befall mit Doldenwelke auf ein Minimum reduziert und die Laborwerte zeigen, dass der Erreger kaum vorhanden ist. Eine Überdachung von der Blüte bis Juli bringt kaum eine Reduktion im Freiland, während eine Überdachung von Juli bis zur Ernte im Freiland noch einen Wirkungsgrad von 45% erzielt, im Labor sogar eine Senkung des Erregerpotenzials um 63%. Nach diesen Ergebnissen spielt die Phase der Blüte also für die Infektion mit Doldenwelke weniger eine Rolle, als bisher vermutet wurde. Beim Schnittversuch kristallisierte sich nach einer Auswertung von vier Versuchsjahren die Variante ‚Schnitt auf 12 Triebe im März’ mit durchgehend konstanten Erträgen heraus, obwohl in dieser Variante mit 16% auch der meiste Ausschuss verworfen werden musste. Ein Schnitt auf 12 Triebe im November erzielte dagegen am wenigsten Ertrag. Ein Schnitt auf acht Triebe resultiert sowohl im November als auch im März in weniger Befall, bringt aber auch weniger Ertrag. Der Blütenschnittversuch zeigte eine deutliche Verringerung an nicht vermarktungsfähiger Ware durch einen Blütenschnitt. Bei einem Schnitt von 50% der Blüten sank der Befall auf 6,7% gegenüber 23% in der Kontrolle. Die Ertragsverringerung belief sich dabei nur auf 30%, teilweise ausgeglichen durch ein höheres Doldengewicht

High Resolution Measurements of Nitrous Oxide (N2O) in the Elbe Estuary

Nitrous oxide (N2O) is one of the most important greenhouse gases and a major sink for stratospheric ozone. Estuaries are sites of intense biological production and N2O emissions. We aimed to identify hot spots of N2O production and potential pathways contributing to N2O concentrations in the surface water of the tidal Elbe estuary. During two research cruises in April and June 2015, surface water N2O concentrations were measured along the salinity gradient of the Elbe estuary by using a laser-based on-line analyzer coupled to an equilibrator. Based on these high-resolution N2O profiles, N2O saturations, and fluxes across the surface water/atmosphere interface were calculated. Additional measurements of DIN concentrations, oxygen concentration, and salinity were performed. Highest N2O concentrations were determined in the Hamburg port region reaching maximum values of 32.3 nM in April 2015 and 52.2 nM in June 2015. These results identify the Hamburg port region as a significant hot spot of N2O production, where linear correlations of AOU-N2Oxs indicate nitrification as an important contributor to N2O production in the freshwater part. However, in the region with lowest oxygen saturation, sediment denitrification obviously affected water column N2O saturation. The average N2O saturation over the entire estuary was 201% (SD: ±94%), with an average estuarine N2O flux density of 48 μmol m−2 d−1 and an overall emission of 0.18 Gg N2O y−1. In comparison to previous studies, our data indicate that N2O production pathways over the whole estuarine freshwater part have changed from predominant denitrification in the 1980s toward significant production from nitrification in the present estuary. Despite a significant reduction in N2O saturation compared to the 1980s, N2O concentrations nowadays remain on a high level, comparable to the mid-90s, although a steady decrease of DIN inputs occurred over the last decades. Hence, the Elbe estuary still remains an important source of N2O to the atmosphere

Microbial methanogenesis in the sulfate-reducing zone of sediments in the Eckernförde Bay, SW Baltic Sea

Benthic microbial methanogenesis is a known source of methane in marine systems. In most sediments, the majority of methanogenesis is located below the sulfate-reducing zone, as sulfate reducers outcompete methanogens for the major substrates hydrogen and acetate. The coexistence of methanogenesis and sulfate reduction has been shown before and is possible through the usage of noncompetitive substrates by methanogens such as methanol or methylated amines. However, knowledge about the magnitude, seasonality, and environmental controls of this noncompetitive methane production is sparse. In the present study, the presence of methanogenesis within the sulfate reduction zone (SRZ methanogenesis) was investigated in sediments (0–30 cm below seafloor, cm b.s.f.) of the seasonally hypoxic Eckernförde Bay in the southwestern Baltic Sea. Water column parameters such as oxygen, temperature, and salinity together with porewater geochemistry and benthic methanogenesis rates were determined in the sampling area "Boknis Eck" quarterly from March 2013 to September 2014 to investigate the effect of seasonal environmental changes on the rate and distribution of SRZ methanogenesis, to estimate its potential contribution to benthic methane emissions, and to identify the potential methanogenic groups responsible for SRZ methanogenesis. The metabolic pathway of methanogenesis in the presence or absence of sulfate reducers, which after the addition of a noncompetitive substrate was studied in four experimental setups: (1) unaltered sediment batch incubations (net methanogenesis), (2) 14C-bicarbonate labeling experiments (hydrogenotrophic methanogenesis), (3) manipulated experiments with the addition of either molybdate (sulfate reducer inhibitor), 2-bromoethanesulfonate (methanogen inhibitor), or methanol (noncompetitive substrate, potential methanogenesis), and (4) the addition of 13C-labeled methanol (potential methylotrophic methanogenesis). After incubation with methanol, molecular analyses were conducted to identify key functional methanogenic groups during methylotrophic methanogenesis. To also compare the magnitudes of SRZ methanogenesis with methanogenesis below the sulfate reduction zone (> 30 cm b.s.f.), hydrogenotrophic methanogenesis was determined by 14C-bicarbonate radiotracer incubation in samples collected in September 2013. SRZ methanogenesis changed seasonally in the upper 30 cm b.s.f. with rates increasing from March (0.2 nmol cm−3 d−1) to November (1.3 nmol cm−3 d−1) 2013 and March (0.2 nmol cm−3 d−1) to September (0.4 nmol cm−3 d−1) 2014. Its magnitude and distribution appeared to be controlled by organic matter availability, C / N, temperature, and oxygen in the water column, revealing higher rates in the warm, stratified, hypoxic seasons (September–November) compared to the colder, oxygenated seasons (March–June) of each year. The majority of SRZ methanogenesis was likely driven by the usage of noncompetitive substrates (e.g., methanol and methylated compounds) to avoid competition with sulfate reducers, as was indicated by the 1000–3000-fold increase in potential methanogenesis activity observed after methanol addition. Accordingly, competitive hydrogenotrophic methanogenesis increased in the sediment only below the depth of sulfate penetration (> 30 cm b.s.f.). Members of the family Methanosarcinaceae, which are known for methylotrophic methanogenesis, were detected by PCR using Methanosarcinaceae-specific primers and are likely to be responsible for the observed SRZ methanogenesis. The present study indicates that SRZ methanogenesis is an important component of the benthic methane budget and carbon cycling in Eckernförde Bay. Although its contributions to methane emissions from the sediment into the water column are probably minor, SRZ methanogenesis could directly feed into methane oxidation above the sulfate–methane transition zone

Vil internett bli fremtidens matbutikk?

Utviklingen av netthandel har økt betraktelig de siste årene og forbrukernes etterspørsel og behov er i endring. Flere bedrifter utfordrer dagligvarebransjen og utformer nye konsepter, hvor kundene kan bestille matvarene sine på nett og få det levert på døren eller til avtalt hentepunkt. Kan denne utviklingen være en ny hverdag og kan internett bli vår femte dagligvareaktør? Det er en meget interessant utvikling som la grunnlaget for problemstillingen vår: «På̊ hvilken måte kan pris, nettsidens brukervennlighet, ordre og leveransehåndtering og vareutvalg påvirke kundens tilfredshet ved matvarehandel på̊ nett?». Vi var nysgjerrige på hva som fører til tilfredshet blant kundene som handler matvarer på internett. For å belyse problemstillingen benytter vi oss av en kvantitativ undersøkelse. Undersøkelsen er preget av noen svakheter som blant annet et begrenset antall respondenter som ikke er hentet fra et sannsynlighetsutvalg. Dette gjør at det er vanskelig å få et representativt utvalg, og i hvilken grad resultatene kan generaliseres. Vi har utviklet fire hypoteser på bakgrunn av relevant forskning og teori, som videre skulle bekreftes eller avkreftes gjennom analyser. Undersøkelsen ga oss flere interessante funn. Vi kunne ikke bekrefte hypotese 1: «Høyt opplevd prisnivå har en negativ effekt på̊ tilfredshet». Resultatene våre sier at økt pris øker tilfredshet. Dette var et overraskende resultat vi ikke hadde forventet oss ettersom dagligvarebransjen i dag er preget av et ønske om lavest mulig pris. Videre antok vi at brukervennlighet ville være en avgjørende faktor for kundenes tilfredshet da hele tjenesten foregår digitalt. Vi fikk heller ikke støtte for hypotese 2: «Nettsidens brukervennlighet har en positiv effekt på̊ tilfredshet». Etter diskusjon av dette resultatet kan det forklares med at nettsider i dag er svært godt utviklet, har standardiserte prosesser og generelt høy standard. Vi fikk derimot støtte for hypotese 3 og 4: «Ordre og leveransehåndtering har en positiv effekt på̊ tilfredshet» og «Godt vareutvalg har en positiv effekt på tilfredshet». Ettersom matvarehandel på nett er bygget opp på et konsept om å få varene levert på døren eller til et avtalt sted er dette en avgjørende dimensjon ved totalopplevelsen og deres tilfredshet. Vareutvalget har også en positiv signifikant sammenheng med tilfredshet og vi ser at kundene ønsker å handle alle varene de trenger på et sted for at matvarehandelen skal gå raskt og enkelt

Case Report: Management of a Multidrug-Resistant CMV-Strain in a Renal Transplant Recipient by High-Dose CMV-Specific Immunoglobulins, Modulation in Immunosuppression, and Induction of CMV-Specific Cellular Immunity

The management of multidrug-resistant strains of cytomegalovirus after solid organ transplantation is challenging. This case report demonstrates the successful treatment of a multidrug-resistant strain of cytomegalovirus that may represent a valuable option for problematic cases. This report illustrates the emergence of a multidrug-resistant cytomegalovirus (CMV) UL54 mutant strain in a renal transplant recipient with severe lymphopenia and thrombocytopenia. We show that the combined treatment with highdose intravenous cytomegalovirus-specific immunoglobulins (CMV-IVIG) after the switch to a mammalian target of rapamycin (mTOR)-inhibitor and cyclosporine A was a successful treatment alternative to direct antiviral treatment with high-dose ganciclovir and foscarnet. This treatment was associated with a quantitative induction of CMVspecific CD4 and CD8 T cells that showed maturation in phenotype and functionality with decreasing viral load. Our case report illustrates that high-dose CMV-IVIG and conversion of immunosuppressive drugs to mTOR inhibitors and cyclosporine A can be a successful treatment in a situation where the use of direct antiviral drugs was considered insufficient

Rates and regulation of nitrogen cycling in seasonally hypoxic sediments during winter (Boknis Eck, SW Baltic Sea): Sensitivity to environmental variables

This study investigates the biogeochemical processes that control the benthic fluxes of dissolved nitrogen (N) species in Boknis Eck - a 28 m deep site in the Eckernförde Bay (southwestern Baltic Sea). Bottom water oxygen concentrations (O2-BW) fluctuate greatly over the year at Boknis Eck, being well-oxygenated in winter and experiencing severe bottom water hypoxia and even anoxia in late summer. The present communication addresses the winter situation (February 2010). Fluxes of ammonium (NH4+), nitrate (NO3-) and nitrite (NO2-) were simulated using a benthic model that accounted for transport andbiogeochemical reactions and constrained with ex situ flux measurements and sediment geochemical analysis. The sediments were a net sink for NO3- (-0.35 mmol m-2 d-1 of NO3-), of which 75% was ascribed to dissimilatory reduction of nitrate to ammonium (DNRA) by sulfide oxidizing bacteria, and 25% to NO3- reduction to NO2- by denitrifying microorganisms. NH4+ fluxes were high (1.74 mmol m-2d-1 of NH4+), mainly due to the degradation of organic nitrogen, and directed out of the sediment. NO2-fluxes were negligible. The sediments in Boknis Eck are, therefore, a net source of dissolved inorganic nitrogen(DIN = NO3- + NO2- + NH4+) during winter. This is in large part due to bioirrigation, which accounts for 76% of the benthic efflux of NH4+, thus reducing the capacity for nitrification of NH4+. The combined rate of fixed N loss by denitrification and anammox was estimated at 0.08 mmol m-2 d-1 of N2, which is at the lower end of previously reported values. A systematic sensitivity analysis revealed that denitrification and anammox respond strongly and positively to the concentration of NO3- in the bottomwater (NO3-BW).Higher O2-BW decreases DNRA and denitrification but stimulates both anammox and the contribution ofanammox to total N2 production (%Ramx). A complete mechanistic explanation of these findings is provided. Our analysis indicates that nitrification is the geochemical driving force behind the observed correlation between %Ramx and water depth in the seminal study of Dalsgaard et al. (2005). Despite remaining uncertainties, the results provide a general mechanistic framework for interpreting the existing knowledge of N-turnover processes and fluxes in continental margin sediments, as well as predicting the types of environment where these reactions are expected to occur prominently