The Information Content of German Discount Rate Changes

Discount rate changes always receive considerable attention in financial markets. Two hypotheses compete to explain financial market reactions: the direct ‘borrowing cost effect’ and the announcement effect. This paper examines the issue for the Bundesbank’s discount rate changes after 1979. Summing up we find that market reactions cannot be attributed to a direct borrowing cost effect but exclusively to announcement effects. The empirical results indicate that interest rates react to changes in the discount rate to the extent that they are unanticipated. In contrast, the response to anticipated changes in the discount rate is small and insignificant. We proxy market anticipations by a multinomial logit-model combined with a dummy variable capturing non-quantifiable factors reported by the financial press. Moreover, we show that the response of interest rates declines along the term structure and with the switch to greater emphasis on repurchase operations in early 1985.discount rate, Bundesbank, announcement effects

Supersymmetry on Graphs and Networks

We show that graphs, networks and other related discrete model systems carry a natural supersymmetric structure, which, apart from its conceptual importance as to possible physical applications, allows to derive a series of spectral properties for a class of graph operators which typically encode relevant graph characteristics.Comment: 11 pages, Latex, no figures, remark 4.1 added, slight alterations in lemma 5.3, a more detailed discussion at beginning of sect.6 (zero eigenspace

Diagnostics-in-a-Suitcase: Development of a portable and rapid assay for the detection of the emerging avian influenza A (H7N9) virus

Background: In developing countries, the necessary equipment for the diagnosis is only available in few central laboratories, which are less accessible and of limited capacity to test large numbers of incoming samples. Moreover, transport conditions of samples are inadequate and therefore lead to unreliable results. Objectives: The development of rapid, inexpensive, and simple test would allow mobile detection of viruses. Study Design: A suitcase laboratory “Diagnostics-in-a-Suitcase” (56 × 45.5 × 26.5 cm) containing all necessary reagents and devices to perform reverse transcription recombinase polymerase amplification (RT-RPA) assay was developed. As an example, Two RT-RPA assays for the detection of hemagglutinin (H) and neuraminidase (N) genes of the novel avian influenza (H7N9) virus were established. Results: Sensitivities were 10 and 100 \{RNA\} molecules for the \{H7\} and the \{N9\} RT-RPA assays, respectively. Assays were performed at a single temperature (42 °C). Results were obtained within 2-7 minutes. The \{H7N9\} RT-RPA assays showed neither a cross-detection of any other respiratory viruses affecting humans and/or birds nor of the human or chicken genomes. All reagents were used, stored, and transported at ambient temperature, i.e. cold chain independent. In addition, the Diagnostics-in-a-Suitcase was operated by a solar power battery. Conclusions: The developed assay protocol and mobile setup performed well. Moreover, it can be easily implemented to perform diagnosis at airport, quarantine stations, or farms for rapid on-site viral nucleic acid detection

Workshop on mobile laboratories deployed in the Ebola outbreak in West-Africa 2014-2015

First paragraph: Ebola virus disease (EVD) is a haemorrhagic fever caused by Ebola virus (EBOV) with high infectivity and mortality. EBOV is an enveloped, single-stranded, and negative-sense RNA virus belonging to the Filoviridae family. In contrast to the genus Marburgvirus which contains one single species, the genus Ebolavirus contains 5 species: Zaire ebolavirus (ZEBOV), Sudan ebolavirus (SUDV), Taï Forest ebolavirus (TAFV), Bundibugyo ebolavirus (BDBV) which are pathogenic for humans, and Reston Ebolavirus (RESTV) which infects non human primates. EBOV was first discovered in 1976 in the Democratic Republic of Congo (DRC) and simultaneously in Sudan. Since 1976, EVD has appeared sporadically in DRC, Sudan, Gabon, Uganda, and Congo, with small to large outbreaks and lethality ranging from 50 to 100% with about 2500 cumulative cases until 2013

COVID-19: The environmental implications of shedding SARS-CoV-2 in human faeces

First paragraph: The ongoing COVID-19 pandemic is having significant public health repercussions, with a global response to limit the predicted mortality associated with this outbreak. The virus, ‘severe acute respiratory syndrome coronavirus 2’ (SARS-CoV-2), is a respiratory virus disseminated though droplets from coughs and sneezes from an infected person or from fomites (Hellewell et al., 2020). Therefore, many countries have put ‘social distancing’ measures in place to reduce person-to-person spread of the disease. However, recently it has been confirmed that infectious virions can also be present in human faeces (Ling et al., 2020), and there are reports that viral RNA can be persistently shed in faeces for a maximum of 33 days after the patient has tested negative for respiratory viral RNA (Wu et al 2020). Although it remains unclear whether SARS-CoV-2 can be transmitted via the faecal-oral route (Xu et al., 2020), viral shedding from the digestive system can last longer than shedding from the respiratory tract. As such, faecal-oral transmission may be an important, but as yet unquantified, pathway for increased exposure during the current outbreak (Wu et al., 2020). Therefore, safely managing faecal wastes from infected, recovering and recovered patients poses a significant nosocomial challenge. For example, during the SARS outbreak of 2002–2003, the closely related SARS-CoV-1 was detected in sewage discharged by two hospitals (Wang et al., 2005), which emphasises the care needed when handling such faecal wastes. However, these challenges are not limited to hospital wastes, as it has been predicted that most of the population will experience only mild symptoms of COVID 19 and convalesce at home, whilst others, including children, can carry the virus asymptomatically, and are still capable of shedding the virus in their faeces (Kam et al., 2020, Tang et al., 2020). This means that the virus could soon become widespread throughout wastewater systems (Naddeo and Liu, 2020). Whilst a lack of testing for the majority of the population makes it difficult to predict the spatially-distributed volume of potentially infectious faeces delivered through the sewerage infrastructure to wastewater treatment works (WWTWs), wastewater surveillance may be a useful tool to indicate where the virus is circulating in the human population (Lodder and de Roda Husman, 2020). However, whilst knowingly infected individuals can take steps to increase their level of hygiene, asymptomatic carriers do not change their behaviour, and can anonymously spread enteric pathogens within the community (Quilliam et al., 2013)

Efficient Screening of Long Oligonucleotides Against Hundred Thousands of SARS-CoV-2 Genome Sequences

An unprecedented use of high-throughput sequencing for routine monitoring of SARS-CoV-2 viruses in patient samples has created a dataset of over 6 million SARS-CoV-2 genomes. To monitor genomes, deposited in the GISAID database, and to track the continuous sequence evolution of molecular assay oligonucleotide target sequences. A simple pipeline tool for non-experts was developed to mine this database for nucleotide changes in oligonucleotides and tested with the long oligonucleotides of a Recombinase polymerase amplification (RPA) assay targeting the RNA-dependent RNA polymerase (RdRP) gene of the SARS-CoV-2. Results indicate the emergence of a single nucleotide change in the reverse oligonucleotide from 0.03 to 26.23% (January to May 2021) in Alpha variant genomes, which however reduced to 17.64% by September after which the Alpha variant was completely displaced by the Delta variant. For all other variants, no relevant nucleotide changes were observed. The oligonucleotide screening pipeline allows efficient screening of nucleotide changes in oligonucleotides of all sizes in minutes

Quantitative real-time PCR detection of Zika virus and evaluation with field-caught mosquitoes

BACKGROUND Zika virus (ZIKV), a mosquito borne flavivirus is a pathogen affecting humans in Asia and Africa. ZIKV infection diagnosis relies on serology-which is challenging due to cross-reactions with other flaviviruses and/or absence or low titer of IgM and IgG antibodies at early phase of infection- virus isolation, which is labor intensive, time consuming and requires appropriate containment. Therefore, real-time RT-PCR (rRT-PCR) is an appealing option as a rapid, sensitive and specific method for detection of ZIKV in the early stage of infection. So far, only one rRT-PCR assay has been described in the context of the outbreak in Micronesia in 2007. In this study, we described a one step rRT-PCR for ZIKV which can detect a wider genetic diversity of ZIKV isolates from Asia and Africa. RESULTS The NS5 protein coding regions of African ZIKV isolates were sequenced and aligned with representative flaviviruses sequences from GenBank to design primers and probe from conserved regions. The analytical sensitivity of the assay was evaluated to be 32 genome-equivalents and 0.05 plaque forming unit (pfu). The assay was shown to detect 37 ZIKV isolates covering a wide geographic in Africa and Asia over 36 years but none of the 31 other flaviviruses tested showing high analytical specificity. The rRT-PCR could be performed in less than 3 hours. This method was used successfully to detect ZIKV strains from field-caught mosquitoes. CONCLUSION We have developed a rapid, sensitive and specific rRT-PCR for detection of ZIKV. This assay is a useful tool for detection of ZIKV infection in regions where a number of other clinically indistinguishable arboviruses like dengue or chikungunya co-circulate. Further studies are needed to validate this assay in clinical positive samples collected during acute ZIKV infection

Reverse transcription recombinase polymerase amplification assay for the detection of middle East respiratory syndrome coronavirus

The emergence of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in the eastern Mediterranean and imported cases to Europe has alerted public health authorities. Currently, detection of MERS-CoV in patient samples is done by real-time RT-PCR. Samples collected from suspected cases are sent to highly-equipped centralized laboratories for screening. A rapid point-of-care test is needed to allow more widespread mobile detection of the virus directly from patient material. In this study, we describe the development of a reverse transcription isothermal Recombinase Polymerase Amplification (RT-RPA) assay for the identification of MERS-CoV. A partial nucleocapsid gene RNA molecular standard of MERS-coronavirus was used to determine the assay sensitivity. The isothermal (42°C) MERS-CoV RT-RPA was as sensitive as real-time RT-PCR (10 RNA molecules), rapid (3-7 minutes) and mobile (using tubescanner weighing 1kg). The MERS-CoV RT-RPA showed cross-detection neither of any of the RNAs of several coronaviruses and respiratory viruses affecting humans nor of the human genome. The developed isothermal real-time RT-RPA is ideal for rapid mobile molecular MERS-CoV monitoring in acute patients and may also facilitate the search for the animal reservoir of MERS-CoV

Testing of NKA expression by mobile real time PCR is an efficient indicator of smoltification status of farmed Atlantic salmon

Assessment of seawater readiness of freshwater salmon smolts is a crucial husbandry step with economic implications in salmon aquaculture but current methods rely on delayed centralised enzymic activity measurement. The efficiency of a qRT-PCR assay for sodium potassium ATPase (NKA) α1a mRNA was tested in a 3-year study on 19 hatcheries across Scotland incorporating environmental factors such as temperature and metal contamination. The NKA qRT-PCR assay was transferred to a mobile laboratory and on-site testing was carried out at 3 hatchery sites. For the first two years standard enzymatic and gene expression assays had similar success rates in detecting smoltification (NKA activity 60%, qRT-PCR 57%). In the third year, all but one site were determined as sea water ready by qRT-PCR but only at 4 by enzymatic testing. On site testing with mobile qRT-PCR was successfully performed on four farm sites. Altogether, high sensitivity was shown for the in lab (98.9%, SE 0.24) and mobile (93.43%, SE 0.119) assays when tested using a quantitative RNA standard. Some indication for obscured smoltification assay results due to environmental increased heavy metal contamination was observed. Our results prove it is possible to test a smoltification marker on site and provide results on the day of testing during the smolt period allowing for informed decisions on seawater transfer

Perturbation Theory of Schr\"odinger Operators in Infinitely Many Coupling Parameters

In this paper we study the behavior of Hamilton operators and their spectra which depend on infinitely many coupling parameters or, more generally, parameters taking values in some Banach space. One of the physical models which motivate this framework is a quantum particle moving in a more or less disordered medium. One may however also envisage other scenarios where operators are allowed to depend on interaction terms in a manner we are going to discuss below. The central idea is to vary the occurring infinitely many perturbing potentials independently. As a side aspect this then leads naturally to the analysis of a couple of interesting questions of a more or less purely mathematical flavor which belong to the field of infinite dimensional holomorphy or holomorphy in Banach spaces. In this general setting we study in particular the stability of selfadjointness of the operators under discussion and the analyticity of eigenvalues under the condition that the perturbing potentials belong to certain classes.Comment: 25 pages, Late