Grazing interactions between Oxyrrhis marina and Synechococcus strains grown in single nitrogen sources

The goal of this study was to assess the interaction between abiotic and biotic factors on diverse Synechococcus strains isolated from the coastal California Current (CC9311, CC9605, CC9902) and the oceanic Sargasso Sea (WH8102 and mutants: JMS40 and SIO7B). Previous research has demonstrated that abiotic factors, such as nutrient source or concentration, can alter cellular structure and chemistry. These cell characteristics in turn influence biotic factors such as predation by protozoan grazers. Synechococcus strains isolated from coastal and open ocean waters were grown to nitrogen (N) depletion in N-reduced medium. After reaching stationary phase, strains were transferred to media containing nitrate, ammonium, urea, proline, alanine, glycine, or glutamine to assess the growth rates for each strain on these individual N sources. Compared to growth rates prior to N-limited stationary phase, all strains increased their growth rate in the single N source media. Synechococcus strains appear to have diverse abilities to grow on a broad range of N sources; however, the pattern of N use was not related to coastal or oligotrophic clade association. The majority of strains showed maximal growth on glycine, rather than on nitrate, ammonium, or urea. However, coastal strain CC9902 and mutants of the Sargasso Sea strain WH8102 either did not grow on or were actively inhibited by several amino acids. Further analysis of cell size, shape, and carbon:nitrogen (C:N) ratios of N source-grown coastal strain CC9311 and oceanic strain WH8102 demonstrated that cell physiological and morphological characteristics, in addition to growth rates, varied among N sources within a strain, as well as between strains. Coastal strain CC9311 and oceanic strain WH8102 were used in 30-minute grazing experiments with the heterotrophic dinoflagellate Oxyrrhis marina. Overall, grazing on coastal strain CC9311 was consistently higher than grazing on open ocean strain WH8102. However, within each strain grazing behavior also varied depending on N sources for strain growth. Physiological and morphological analysis of prey, in concert with grazing experiments, suggested that N source alters prey morphology and physiology, and the predator O. marina responds to these cell alterations. While many characteristics such as C and N content, cell size, and cell shape were inter-related, grazing on coastal strain CC9311 was strongly linked to cell shape (highest on more rounded cells) and C and N content (higher on cells with higher nutrient content). In contrast to coastal strain CC9311, few clear relationships could be discerned between ocean strain WH8102 N source-grown cell characteristics and the feeding behavior of the heterotrophic dinoflagellate, O. marina. While previous work has shown that O. marina readily eats coastal strain CC9311, this study showed O. marina grazing rate is also affected by prey growth condition, reflected in the physiology and morphology of the cell. Further studies expanding the breadth of protozoan predators and Synechococcus strains would aid in the understanding of the microzooplankton\u27s role in top-down control of Synechococcus populations under different nutrient regimes and in more general issues of how resource use might affect predation

Migration Pattern Dynamics during Choroid Fissure Closure in Zebrafish

Successful closure of the choroid fissure (CF) is essential for proper development of the vertebrate eye. The impermanent structure forms as the optic cup surrounds the invaginating lens allowing hyaloid vasculature to enter the developing eye. If the choroid fissure closure (CFC) fails to close, a coloboma develops associated with approximately 3-11% of childhood blindness worldwide. The CF cells are distinct prior to fusion as they remain undifferentiated until fusion of the opposing sides and have unique N-cadherin expression. During CFC, cells must breakdown basement membrane to allow fusion between both sides producing a seamless ventral retina. Both breakdown and fusion of the apposing sides of the CF initiate from the central region and proceeds bi-directionally. It is unknown however where or if the CF cells migrate away from an aligned fusion point. in vivo confocal microscopy of transgenic Hsp701:Gal4;UAS:Kaede zebrafish embryos during CFC allows distinctive contrast of photoconverted cells to give insight to their spatial temporal movement. We partitioned our analysis into three distinct regions along the proximal/distal axis of the CF to determine if cellular movement at the choroid fissure edges maintained distinct cellular migration patterns prior to differentiation. Preliminary analysis from 44 to 48 hpf in the proximal and distal regions demonstrate movement distinct from those within the central region. In both proximal and distal CF, upper (dorsal) CF cells move towards the central CF changing their proximal/distal axis in the opposite direction of fusion. Lower (ventral) CF cells move further ventrally towards the apposing side in order to fuse the CF. This contrasts with the central CF upper and lower cells that move directly towards the apposed sides. These results further support the hypothesis that cells at the CF edge are regulated differentially from the remaining differentiating retina

Prototyp eines mobilen Warenausgangs- und Liefersystems

Der zu erwartende Wandel des gesamten Marktes in den nächsten Jahren – insbesondere durch den Einsatz von eCommerce und mCommerce – macht auch eine Anpassung der Unternehmen und ihrer Logistik erforderlich. Der Einsatz moderner Informationstechnologie (IT) erlaubt die Optimierung von Prozessen und einen verbesserten Kundenservice, wie z. B. die Verfolgung von Paketen, die heute bei kleinen und mittleren Speditionen noch nicht zum Standard gehört. Durch den Einsatz von Warenwirtschaftssystemen mit Barcodeintegration wird in Großhandelsunternehmen mit eigenem Fuhrpark eine Paketverfolgung nur bis zur Laderampe, also „Inhouse“, gesichert. Die weiterführende Verfolgung der Sendungen fehlt jedoch. In größeren Logistikunternehmen ist, durch Ausstattung der Nutzfahrzeuge mit relativ aufwändiger Bordelektronik, das Tracking und Tracing der Versandeinheiten zwar weitestgehend gesichert. Verbesserungspotential liegt hier aber unter anderem in der Disposition und im Tracking der Transporthilfsmittel (Gitterboxen, Paletten), die zurzeit in der Regel noch nicht systematisch erfasst und verfolgt werden

The Impact of Electronic Commerce on the Automotive Industry

The diffusion of the Internet (and comparable communication infrastructures) has led to the emergence of a virtual global marketspace in which products and services are sold electronically. As a result, traditional intermediaries, such as travel agents or retailers, are being bypassed. This development effects not only products and services which can be digitized but also the marketing and distribution of physical products. We have scrutinized the interdependencies of product characteristics and traditional distribution structure, electronic commerce andthe emergence of new services and distribution structures trends in the automotive industry. The auto manufacturers are facing difficult choices on several fronts at a time: cybermediaries, independent (mega-)dealers and their own direct sales operations on the Web are competing with their exclusive dealers. Based on this analysis which reveals patterns of exacerbated competition, we will discuss strategic options for a business network redesig

A taxonomic revision of ten whitefish species from the lakes Lucerne, Sarnen, Sempach and Zug, Switzerland, with descriptions of seven new species (Teleostei, Coregonidae)

The taxonomy of the endemic whitefish of the lakes of the Reuss River system (Lucerne, Sarnen, Zug) and Lake Sempach, Switzerland, is reviewed and revised. Lake Lucerne harbours five species. Coregonus intermundia sp. nov. and C. suspensus sp. nov., are described. Coregonus nobilis Haack, 1882, C. suidteri Fatio, 1885, and C. zugensis Nüsslin, 1882, are redescribed. Genetic studies have shown that C. suidteri and C. zugensis are composed of several distinct species endemic to different lakes. The names C. suidteri and C. zugensis are restricted to the species of lakes Sempach and Zug, respectively. The whitefish populations previously referred to as C. suidteri and C. zugensis from Lake Lucerne are described as C. litoralis sp. nov. and C. muelleri sp. nov., respectively. Furthermore, the whitefish from Lake Zug that were previously referred to as C. suidteri are described as C. supersum sp. nov. A holotype is designated for C. supersum that was previously one of two syntypes of C. zugensis. The other syntype is retained for C. zugensis. Coregonus obliterus sp. nov. is described from Lake Zug, and C. obliterus and C. zugensis from Lake Zug are extinct. Finally, we describe C. sarnensis sp. nov. from lakes Sarnen and Alpnach. Coregonus suidteri from Lake Sempach shows strong signals of introgression from deliberately translocated non-native whitefish species, which questions if the extant population still carries a genetic legacy from the original species and thus may need to be considered extinct. Coregonus suspensus is genetically partially of allochthonous origin, closely related to the radiation of Lake Constance. It is therefore compared to all known and described species of Lake Constance: C. wartmanni Bloch, 1784, C. macrophthalmus Nüsslin, 1882, C. arenicolus Kottelat,1997, and C. gutturosus Gmelin, 1818

Datenerfassung und Visualisierung von Vitalparametern und Primärsignalen auf dem Computer und auf mobilen Endgeräten

In Kliniken besteht der Bedarf nach einer lückenlosen Aufzeichnung der Vitalparameter (z. B. Herzfrequenz, Blutdruck) und Primärsignale (z. B. EKG). Besonders in der Notfallmedizin ist eine ständige Patientenüberwachung lebensnotwendig. Zudem dienen die erfassten Daten der aktuellen Patienten-Dokumentation, aber auch zur Analyse im Bereich der Forschung und für Studien. Für diesen Zweck wurde das Telematik-System »Multi-Patientenmonitoring« entwickelt. Dieses System dient der Datenerfassung, Signalvisualisierung und Echtzeitübertragung von Vitalparametern an beliebig viele PCs und mobile Geräte des Krankenhausnetzwerkes. Motiviert durch das Universitätsklinikum Tübingen wurde das Projekt von der Wildauer Firma ixellence initiiert und in interdisziplinärer Zusammenarbeit mit medizinischen Einrichtungen, dem Fachgebiet Telematik an der TFH Wildau und der Philips Medizin-Systeme GmbH realisiert.Hospitals need a complete recording of vital parameters (e.g. heart frequency, blood pressure) and primary signals (e.g. ECG). Especially in intensive care units the permanent monitoring and the recording of the current status of the patient is vital. Furthermore, these data are useful for the patient documentation and in fields of research and studies. For this purpose a multi-monitoring system was developed. This system provides the data acquisition, signal visualization and real time transmission of vital parameters to PCs and mobile devices in the hospital network. With this system it is possible to get a fast overview of the current patient status and its history. Furthermore physicians can monitor the patients mobile and in real time. The project was developed in co-operation with medical research facilities, the Chair of Telematics at the University of Applied Sciences in Wildau, and with the companies Philips Medical Systems and ixellence

“Was it useful? Like, really?”: Client and Consultant Perceptions of Post-Session Satisfaction Surveys

Client satisfaction surveys have long been a cornerstone of writing center assessment, but to date, research on satisfaction surveys has largely focused on analyzing client responses from the survey and their administrative uses. Research rarely investigates why clients provide the responses they do and how consultants process these responses. This study, therefore, involved conducting separate client and consultant focus groups to learn about each population’s interactions with one writing center’s optional post-session satisfaction survey and the survey results. The findings revealed that while client participants used the survey to communicate high levels of satisfaction, client participants also thought about the survey in multifaceted ways that took into account complex factors, such as their relationship with the writing center and care for consultants’ feelings. The study also showed that consultant participants valued positive feedback from clients but that consultants found their survey responses to have limited utility for professional growth and that they craved more specific and constructive feedback. This article offers considerations for how writing center professionals can better communicate the purpose of surveys to both clients and consultants, and it proposes additional forms of assessment that could allow consultants and administrators to hear the nuanced feedback clients can offer