Molecular and morphometric analysis of (semi-)cryptic species in Fragilariopsis kerguelensis

The diatom species Fragilariopsis kerguelensis is endemic to the Southern Ocean where it plays a key role in the ocean silica cycle due to its heavily silicified cell walls. Frustules from dead cells can sink to the ocean floor and therefore contribute about 90% to the diatom frustules making up the Antarctic opal belt, a band of heavily silicified sediments below the Antarctic Circumpolar Current. Recent studies showed that two morphotypes of F. kerguelensis can be found in core samples originating from the Southern Ocean. The morphotypes can be distinguished by the morphometric descriptor rectangularity and the abundance of the morphotypes can be linked to the origin of the samples from glacial or interglacial periods. It is, however, so far unknown whether these morphotypes also occur in current diatom assemblages of the Southern Ocean; if yes, how their occurrence is influenced by environmental conditions; and whether they represent different species, or rather phenotypic plasticity within a single species. For answering these questions diatom valves in water and sediment samples from the Southern Ocean, preserved on microscopic slides were analysed morphologically using a semi automated morphometry workflow. Histograms of the rectangularity were then plotted which all showed a bimodal distribution proving the existence of the two morphotypes in recent samples. In the next step the biogeographic distribution pattern of the two morphotypes was assessed by plotting the rectangularity distribution at each sample station. Whereas one morphotype was dominant in the northernmost samples, its dominance decreased towards the south, and the other morphotype became dominant in the southernmost locations investigated. This pattern could also be linked to the Sea Surface Temperature with a regression. After the previous findings the question arose if the morphotypes could be cryptic species or if they occur due to phenotypic plasticity within a single species. To answer this a genetic assessment with diatom strains showing different rectangularity values, isolated from the Southern Ocean and kept in live cultures at the Alfred-Wegener-Institut was done. Their ribosomal internal transcribed spacer (ITS) regions were amplified using PCR and then analysed with Sanger sequencing. The results made it possible to identify three potential species based on their genetic differences. One semi-cryptic species was solely made up of morphotype B whereas morphotype A was divided in two genetic clusters representing two cryptic species. Mating experiments were carried out to uncover possible reproductive barriers between the cryptic species. The results showed, that strains being assigned the same cryptic species commonly sexually reproduce, whereas sexual reproduction between strains from different cryptic species was only observed in a few exceptions. In summary, the two investigated morphotypes of Fragilariopsis kerguelensis can be found in the Southern Ocean today, with one dominating at higher, the other at lower Sea Surface Temperatures. Comparison of ribosomal ITS sequences and mating experiments indicate that the two morphotypes seem to belong to three different species, one semi-cryptic species belonging to one and two cryptic species to the other morphotype

Mobilfunknutzung in Deutschland: eine Herausforderung für die Stichprobenbildung in der Markt- und Sozialforschung

Der Autor geht der Frage nach, ob die Telefonstichproben der Markt- und Sozialforschung, die auf einem Auswahlmechanismus beruhen, welcher im Normalfall ausschließlich Festnetzrufnummern beinhaltet, im Jahre 2007 noch geeignet sind, qualitativ hochwertige Stichproben der Gesamtbevölkerung zu liefern. Denn die Zunahme der Mobilfunknutzung führt dazu, dass die Erreichbarkeit im Festnetz nicht mehr gegeben ist. Nicht nur die Anzahl derjenigen, die ausschließlich Mobilfunk nutzen, ist dabei von Interesse, sondern es kommt ein zweiter Aspekt hinzu: Gibt es systematische Unterschiede zwischen diesen beiden Subpopulationen und wenn ja, welche? Mit diesen beiden Fragekomplexen beschäftigt sich der erste Abschnitt des Beitrags anhand von Befragungsdaten aus dem TNS Infratest Face-to-Face-Omnibus. Im zweiten Abschnitt wird dargestellt, welche Lösungsansätze im Hinblick auf eine Integration der Mobilfunknummern in einen Auswahlrahmen für Telefonstichproben bislang verfolgt wurden. Abschließend werden einige weiterführende Aspekte diskutiert, die für die noch ausstehende Lösung des Mobilfunkproblems in Zukunft relevant sein könnten. (ICI2)"The article deals with the increasing use of mobile phones (cellular phones) in Germany with regard to the impact on probability sampling based on landline sample frames. Although the mobile penetration in the population is on a high density level the exclusive use of cell-phones and the abdication of fixed-line-telephones is quiet rare. Nevertheless the mobile-only-use has in some sub-populations reached a critical stage. In the last years research on methods of Market- und Social-Research have tried several ways of including mobile-phone-numbers in random telephone-samples. Currently a special form of random-last-digit approach, based on sophisticated reference lists not on the telephone-book, seems to be the most promising solution. Furthermore a coherent sample-design still needs to be developed in order to ensure efficient fieldwork and acceptable pricing. Last but not least the dynamic of the telecommunication sector should not be lost of track. On the one hand broadband internet connections will perhaps revitalise landline-phones. On the other hand new technical solutions will come up soon and will lead to further problems and possibilities for the future." (author's abstract

Vanadium oxide monolayer catalysts. I. Preparation, characterization, and thermal stability

Vanadium oxide catalysts of the monolayer type have been prepared by means of chemisorption of vanadate(V)-anions from aqueous solutions and by chemisorption of gaseous V2O3(OH)4. Using Al2O3, Cr2O3, TiO2, CeO2 and ZrO2, catalysts with an approximately complete monomolecular layer of vanadium(V) oxide on the carrier oxides can be prepared, if temperature is not too high. Divalent metal oxides like CdO and ZnO may already form threedimensional surface vanadates at moderate temperature. \ud The thermal stability of a monolayer catalyst is related to the parameter z/a, i. e. the ratio of the carrier cation charge to the sum of ionic radii of carrier cation and oxide anion. Thus, monolayer catalysts will be thermally stable only under the condition that z/a is not too high (aggregated catalyst) nor too small (ternary compound formation)

Adaptive divergence across Southern Ocean gradients in the pelagic diatom Fragilariopsis kerguelensis

The Southern Ocean is characterized by longitudinal water circulations crossed by strong latitudinal gradients. How this oceanographic background shapes planktonic populations is largely unknown, despite the significance of this region for global biogeochemical cycles. Here, we show, based on genomic, morphometric, ecophysiological and mating compatibility data, an example of ecotypic differentiation and speciation within an endemic pelagic inhabitant, the diatom Fragilariopsis kerguelensis. We discovered three genotypic variants, one present throughout the latitudinal transect sampled, the others restricted to the north and south, respectively. The latter two showed reciprocal monophyly across all three genomes and significant ecophysiological differences consistent with local adaptation, but produced viable offspring in laboratory crosses. The third group was also reproductively isolated from the latter two. We hypothesize that this pattern originated by an adaptive expansion accompanied by ecotypic divergence, followed by sympatric speciation

A vast icefish breeding colony discovered in the Antarctic

A breeding colony of notothenioid icefish (Neopagetopsis ionah, Nybelin 1947) of globally unprecedented extent has been discovered in the southern Weddell Sea, Antarctica. The colony was estimated to cover at least similar to 240 km(2) of the eastern flank of the Filchner Trough, comprised of fish nests at a density of 0.26 nests per square meter, representing an estimated total of -60 million active nests and associated fish biomass of >60,000 tonnes. The majority of nests were each occupied by 1 adult fish guarding 1,735 eggs (+/- 433 SD). Bottom water temperatures measured across the nesting colony were up to 2 degrees C warmer than the surrounding bottom waters, indicating a spatial correlation between the modified Warm Deep Water (mWDW) upflow onto the Weddell Shelf and the active nesting area. Historical and concurrently collected seal movement data indicate that this concentrated fish biomass may be utilized by predators such as Weddell seals (Leptonychotes weddellii, Lesson 1826). Numerous degraded fish carcasses within and near the nesting colony suggest that, in death as well as life, these fish provide input for local food webs and influence local biogeochemical processing. To our knowledge, the area surveyed harbors the most spatially expansive continuous fish breeding colony discovered to date globally at any depth, as well as an exceptionally high Antarctic seafloor biomass. This discovery provides support for the establishment of a regional marine protected area in the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) umbrella

A vast icefish breeding colony discovered in the Antarctic

A breeding colony of notothenioid icefish (Neopagetopsis ionah, Nybelin 1947) of globally unprecedented extent has been discovered in the southern Weddell Sea, Antarctica. The colony was estimated to cover at least �240 km2 of the eastern flank of the Filchner Trough, comprised of fish nests at a density of 0.26 nests per square meter, representing an estimated total of �60 million active nests and associated fish biomass of >60,000 tonnes. The majority of nests were each occupied by 1 adult fish guarding 1,735 eggs (±433 SD). Bot- tom water temperatures measured across the nesting colony were up to 2�C warmer than the surrounding bottom waters, indicating a spatial correlation between the modified Warm Deep Water (mWDW) upflow onto the Weddell Shelf and the active nesting area. Historical and concurrently collected seal movement data indicate that this concentrated fish biomass may be utilized by predators such as Weddell seals (Lep- tonychotes weddellii, Lesson 1826). Numerous degraded fish carcasses within and near the nesting colony suggest that, in death as well as life, these fish provide input for local food webs and influence local biogeo- chemical processing. To our knowledge, the area surveyed harbors the most spatially expansive continuous fish breeding colony discovered to date globally at any depth, as well as an exceptionally high Antarctic sea- floor biomass. This discovery provides support for the establishment of a regional marine protected area in the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) umbrella

Utilising light-emitting diodes of specific narrow wavelengths for the optimization and co-production of multiple high-value compounds in Porphyridium purpureum

The effect of specific narrow light-emitting diode (LED) wavelengths (red, green, blue) and a combination of LED wavelengths (red, green and blue - RGB) on biomass composition produced by Porphyridium purpureum is studied. Phycobiliprotein, fatty acids, exopolysaccharides, pigment content, and the main macromolecules composition were analysed to determine the effect of wavelength on multiple compounds of commercial interest. The results demonstrate that green light plays a significant role in the growth of rhodophyta, due to phycobiliproteins being able to harvest green wavelengths where chlorophyll pigments absorb poorly. However, under multi-chromatic LED wavelengths, P. purpureum biomass accumulated the highest yield of valuable products such as eicosapentaenoic acid (~2.9 %DW), zeaxanthin (~586 μg g− 1 DW), β-carotene (397 μg g− 1 DW), exopolysaccharides (2.05 g/L-1), and phycobiliproteins (~ 4.8 % DW). This increased accumulation is likely to be the combination of both photo-adaption and photo-protection, under the combined specific wavelengths employed

Seroepidemiological study on the spread of SARS-CoV-2 in Germany:

The SARS-CoV-2 coronavirus has spread rapidly across Germany. Infections are likely to be under-recorded in the notification data from local health authorities on laboratory-confirmed cases since SARS-CoV-2 infections can proceed with few symptoms and then often remain undetected. Seroepidemiological studies allow the estimation of the proportion in the population that has been infected with SARS-CoV-2 (seroprevalence) as well as the extent of undetected infections. The ‘CORONA-MONITORING bundesweit’ study (RKI-SOEP study) collects biospecimens and interview data in a nationwide population sample drawn from the German Socio-Economic Panel (SOEP). Participants are sent materials to self-collect a dry blood sample of capillary blood from their finger and a swab sample from their mouth and nose, as well as a questionnaire. The samples returned are tested for SARS-CoV-2 IgG antibodies and SARS-CoV-2 RNA to identify past or present infections. The methods applied enable the identification of SARS-CoV-2 infections, including those that previously went undetected. In addition, by linking the data collected with available SOEP data, the study has the potential to investigate social and health-related differences in infection status. Thus, the study contributes to an improved understanding of the extent of the epidemic in Germany, as well as identification of target groups for infection protection

Ten years of invasion: Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Britain

1. Harmonia axyridis was first recorded in Britain in 2004. Two subsequent earlier records were received from 2003. 2. The UK Ladybird Survey, a citizen science initiative involving online recording, was launched in 2005 to encourage people across Britain to track the spread of H. axyridis. Tens of thousands of people have provided records of H. axyridis and other species of ladybirds, creating an invaluable dataset for large-scale and long-term research. Declines in the distribution of seven (of eight assessed) native species of ladybird have been demonstrated, and correlated with the arrival of H. axyridis, using the records collated through the UK Ladybird Survey. 3. Experimental research and field surveys have also contributed to our understanding of the ecology of H. axyridis and particularly the process of invasion. Harmonia axyridis arrived in Britain through dispersal and introduction events from regions in which it was deliberately released as a biological control agent. The rapid spread of this species has been attributed to its high natural dispersal capability by means of both flight and anthropogenic transport. A number of factors have contributed to the successful establishment and indeed dominance of this polymorphic species within aphidophagous guilds, including high reproductive capacity, intra-guild predation, eurytopic nature, high resistance to natural enemies within the invaded range, and potentially phenotypic plasticity. 4. The global invasion by H. axyridis and subsequent research on this species has contributed to the general understanding of biological invasions