Quantitative detection of _Potato virus Y_ in potato plants and aphids - Discussion of diverse applications in potato research

Every year potato growers worldwide complain about severe yield losses caused by _Potato virus Y_ (PVY). Therefore, PVY along with _Potato leafroll virus_ belongs to the most important potato viruses. There are three main strains of PVY: PVY^O^, PVY^N^ and PVY^C^. However, also recombinant forms exist such as PVY^N^Wilga and PVY^NTN^, both of which increase in importance due to their potential to displace the non-recombinant strains at a high percentage. They appear also in mixed infections. In recent years PCR and qPCR assays were developed to differentiate PVY isolates. In order to identify PVY isolates by PCR often large amplicons have to be generated which requires the input of expensive enzymes. On the other hand, qPCR assays until now do not allow the differentiation between PVY^N^Wilga and PVY^NTN^. 

For the discrimination between PVY^O^/PVY^N^Wilga and PVY^N^/PVY^NTN^ a qPCR assay was developed, which allows the differentiation and highly efficient quantification of both strains and recombinants, respectively. For this purpose dual-labeled hydrolysis probes tagged with different fluorophores were designed. The assay is suitable for many different applications, for example safety research on genetically modified (GM) potato plants. The goal of this research is to determine whether genetic modification causes changes in resistance to viruses. Two different GM cultivars were examined for signs of altered resistance to an infection with PVY in comparison to their near-isogenic lines and three reference cultivars. Reference cultivars are included to determine the baselines for resistance and thus to be able to decide if the changes could represent a biological risk. The plants to be investigated were mechanically inoculated with PVY^N^Wilga or PVY^NTN^ and analyzed by means of the developed assay after two weeks. The results of the experiment indicate that the differences in virus titer between the reference cultivars are higher than between the GM potatoes and their isogenic lines. Therefore, in our experiments the GM potato plants showed no alteration in PVY resistance to neither one of the tested strains.

Since _Myzus persicae_ is one of the most important vectors transmitting PVY, the developed assay will also be applied to the quantification of PVY particles in aphids. The displacement of PVY^O^ and PVY^N^ by PVY^N^Wilga and PVY^NTN^ may be due to a difference in efficiency of transmission by _M. persicae_. Therefore, the objective is to test whether more virus particles of the recombinant forms in comparison to the non-recombinant strains PVY^O^ and PVY^N^ bind in the stylets of _M. persicae_. 

A third possible application of the developed assay may be of interest in potato breeding. The exact quantification of PVY particles in plants allows the classification of resistance in potato plants. It is possible to estimate whether a resistance is extreme or not. Extreme resistance is characterized by the absence or presence of very low amounts of virus particles in plants several days after inoculation. When testing the plants for PVY infection by ELISA, often unspecific reactions occur which makes it difficult to differentiate between plants weakly infected and plants very weakly infected. An exact quantification of the PVY titer gives more certainty for the determination of the resistance type.

In conclusion, the developed assay is an efficient and low-cost method that allows the differentiation and quantification of PVY^O^/PVY^N^Wilga on the one hand and PVY^N^/PVY^NTN^ on the other hand with high throughput. The method can be utilized for a wide range of applications in potato research.
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Enzymatic Hydrolysis of Porang by Streptomyces Violascens BF 3.10 Mannanase for the Production of Mannooligosaccharides

Porang (Amorphophallus muelleri Blume) is an indigenous Indonesian plant containing high hemicellulose as a source of glucomannan. An alternative way to produce a good quality of mannooligosaccharides was through hydrolysis of glucomannan by endo-β mannnase from actynomicetes. Based on 16S rRNA analysis, BF 3.10 isolate, isolated from Bukit Duabelas National Park soil, Jambi was identified as Streptomyces violascens BF 3.10. Reducing sugar was analyzed by dinitrosalicylic acid methods. The highest reducing sugar was achieved at the 72 hours of incubation. Mannanase of isolate BF 3.10 had the highest activity at pH 6 and temperature of 70 °C with enzyme activity of 16.38 U/mL and was stable at 4 °C for 48 h. During 5-hour of hydrolysis with substrate concentration of 0.25%, 0.5%, and 1% porang glucomannan dissolved in 10 mL enzyme, mannooligosaccharides were produced with the degree of polymerization of 2-3. Visualization of the products by using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) methods showed that mannooligosaccharides produced comprised of glucose, mannobiose, mannotriose, and mannotetraose. The degree of polymerization and the simple sugars produced indicated that mannanase produced by S. violascens actively catalyzed the hydrolysis of 1.4-β-D-mannoside linkage from β-1.4-mannan backbone, that eventually produced simple sugars of mannooligosaccharides

Political Violence and Excess Liquidity in Egypt

In this article we estimate a time-series model of excess liquidity in the Egyptian banking sector. While financial liberalisation and financial stability are found to have reduced excess liquidity, these effects have been offset by an increase in the number of violent political incidents arising from conflict between radical Islamic groups and the Egyptian state. The link between political events and financial outcomes provides a rationale for economic policy interventions by the international community in response to increases in political instability

Cisplatin-Based Chemotherapy for Pulmonary Metastasized Germ Cell Tumors of the Testis - Be Aware of Acute Respiratory Distress Syndrome

Background: Cisplatin-based combination chemotherapy is regarded as standard of care for patients with advanced germ cell tumors. In patients with lung metastases and a high tumor load, an association between induction chemotherapy and the development of a `tumor-associated' acute respiratory distress syndrome (ARDS) has been hypothesized. Case Report: We report the clinical course of a 19-year-old patient who rapidly developed fatal ARDS during the first cycle of chemotherapy using the PEI regimen (cisplatin, etoposide and ifosfamide) for a metastasized (lung, liver, lymph nodes) germ cell tumor of the testis. Conclusion: Further clinical research in order to better define risk factors for developing ARDS in this patient population as well as novel strategies for the prevention and treatment of ARDS in those patients are necessary

The Tale of the Three Brothers – Shh, Wnt, and Fgf during Development of the Thalamus

The thalamic complex is an essential part of the brain that requires a combination of specialized activities to attain its final complexity. In the following review we will describe the induction process of the mid-diencephalic organizer (MDO) where three different signaling pathways merge: Wnt, Shh, and Fgf. Here, we dissect the function of each signaling pathway in the thalamus in chronological order of their appearance. First we describe the Wnt mediated induction of the MDO and compartition of the caudal forebrain, then the Shh mediated determination of proneural gene expression before discussing recent progress in characterizing Fgf function during thalamus development. Then, we focus on transcription factors, which are regulated by these pathways and which play a pivotal role in neurogenesis in the thalamus. The three signaling pathways act together in a strictly regulated chronology to orchestrate the development of the entire thalamus

Mehrwertorientierte Gestaltung mobiler Dienste im Fahrzeug : eine empirische Untersuchung von Nutzeranforderungen

Stagnierende Märkte und veränderte Kundenanforderungen eröffnen in der Automobilindustrie die Suche nach neuen, Erfolg versprechenden Geschäftsmodellen. Automobilhersteller entdecken dabei zune hmend das Potenzial des Mobile Business, sehen sich bei der Erweiterung ihres ur sprünglichen Kerngeschäftes durch die Integration von mobilen Diensten in das Fahrzeug jedoch gleichzeitig mit neuen Herausforderungen konfrontiert. Um in den Augen der Nachfrager einen erkennbaren Mehrwert zu stiften und somit die nutzerseitige Akzeptanz von mobilen Diensten im Fahrzeug zu sichern, müssen sich die Anbieter verstärkt an den Bedürfnissen ihrer Kunden orientieren. Ausgangspunkt für die vorliegende Arbeit, der en zentrales Ziel die Identifizierung und Analyse nutzenstiftender Elemente von mobilen Diensten ist, sind die bisher geringen Forschungsaktivitäten im Hinblick auf eine kundenorientierte Gestaltung von mobilen Anwendungen im Fahrzeug. Eine Expertenbefragung soll zunächst Aufschluss über die zentralen Eigenschaft en des Leistungsbündels „mobile Dienste“ geben. Anschließend erfolgt auf Grundlage einer internetbasierten Konsumentenbefragung eine Analyse der Präferenzstrukturen von potenziellen Nutzern mobiler Dienste im Rahmen einer Adaptiven Conjoint-Analyse. Im letzten Untersuchungsschritt werden mittels einer Clusteranalyse homogene Käufergruppen identifiziert und segmentspezifische Gestaltungsempfehlungen abgeleitet

User requirements for location based services : an analysis on the basis of literature

The high global penetration of mobile telephony provides a strong basis for the development and diffusion of mobile business applications. Especially for location based services, i.e. mobile services that consider the user’s current location to add value to the service provided, a high potential to become a major market success is seen. Nevertheless the development of mobile business and location based services has so far been lagging behind expert expecations. One of the reasons for this disappointing development is the failure of application developers to center their efforts on potential users and their needs and demands. The following paper therefore reviews the existing literature on user requirements in mobile business and location based services. A definition and characterization of location based services is given and a framework to categorize existing location based services is developed. Additionally, usefulness and usability are put in concrete terms as they are identified as the main determinants of end-user acceptance of location based services. Security concerns of potential users of location based services are analyzed and further limitations of the diffusion of location based services are discussed

Location Based Services in Deutschland : eine qualitative Marktanalyse auf Basis von Experteninterviews

Trotz der hohen Potenzialeinschätzungen für Location Based Services (LBS) ist die Entwicklung des LBS-Marktes in Deutschland bisher hinter den Erwartungen zurückgeblieben. Die Ursachen hierfür sind bisher weder auf Praxis- noch auf Forschungsseite identifiziert und ausführlich analysiert worden. Die vorliegende Untersuchung zielt daher darauf ab, die Gründe für die hinter den Erwartungen zurück bleibende Entwicklung herauszuarbeiten. Hierzu wird eine qualitative Expertenbefragung in der LBS-Branche durchgeführt. Als Ergebnis der Untersuchung erweisen sich neben technischen Barrieren insbesondere die Unwissenheit und Verunsicherung auf Seiten der Nutzer als Diffusionshemmnisse von LBS. Zudem zeigt sich, dass die derzeitige Struktur der Wertschöpfungskette suboptimal für eine erfolgreiche Marktentwicklung ist. Chancen für die Diffusion von LBS stellen nach Ansicht der befragten Experten die allgemeine gesellschaftliche Entwicklung, der Trend zu Mobilität sowie der Druck zu erhöhter Produktivität und Effizienz dar. Schließlich lassen sich aus den Befragungsergebnissen fünf zentrale Herausforderungen ableiten, welche von den Anbietern ortsbezogener Dienste zu adressieren sind

Individual Values and SME Environmental Engagement

We study the values on which managers of small and medium-sized enterprises draw when constructing their personal and organizational-level engagement with environmental issues, particularly climate change. Values play an important mediating role in business environmental engagement but relatively little research has been conducted on individual values in smaller organizations. Using the Schwartz Value System (SVS) as a framework for a qualitative analysis, we identify four ‘ideal-types’ of SME managers and provide rich descriptions of the ways in which values shape their constructions of environmental engagement. In contrast to previous research, which is framed around a binary divide between self-enhancing and self-transcending values, our typology distinguishes between individuals drawing primarily on Power or on Achievement values, and indicates how a combination of Achievement and Benevolence values is particularly significant in shaping environmental engagement. This demonstrates the theoretical usefulness of focusing on a complete range of values. Implications for policy and practice are discussed