A Novel Rapid Sample Preparation Method for MALDI-TOF MS Permits Borrelia burgdorferi Sensu Lato Species and Isolate Differentiation

The genus Borrelia comprises vector-borne bacterial pathogens that can severely affect human and animal health. Members of the Borrelia burgdorferi sensu lato species complex can cause Lyme borreliosis, one of the most common vector-borne diseases in the Northern hemisphere. Besides, members of the relapsing fever group of spirochetes can cause tick-borne relapsing fever in humans and various febrile illnesses in animals in tropical, subtropical and temperate regions. Borrelia spp. organisms are fastidious to cultivate and to maintain in vitro, and therefore, difficult to work with in the laboratory. Currently, borrelia identification is mainly performed using PCR and DNA sequencing methods, which can be complicated/frustrating on complex DNA templates and may still be relatively expensive. Alternative techniques such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) are not well established for Borrelia spp., although this technique is currently one of the most used techniques for rapid identification of bacteria in microbiological diagnostic laboratories. This is mainly due to unsatisfactory results obtained by use of simple sample preparation techniques and medium-contamination obscuring the mass spectra. In addition, comprehensive libraries for Borrelia spp. MALDI-TOF MS have yet to be established. In this study, we developed a new filter-based chemical extraction technique that allows measurement of high quality Borrelia spp. spectra from less than 100,000 bacteria per spot in MALDI-TOF MS. We used 49 isolates of 13 different species to produce the largest mass-library for Borrelia spp. so far and to validate the protocol. The library was successfully established and identifies >96% of used isolates correctly to species level. Cluster analysis on the sum spectra was applied to all the different isolates, which resulted in tight cluster generation for most species. Comparative analysis of the generated cluster to a phylogeny based on concatenated multi-locus sequence typing genes provided a surprising homology. Our data demonstrate that the technique described here can be used for fast and reliable species and strain typing within the borrelia complex

Electrodeposition of cobalt based ferro-magnetic metal nanowires in polycarbonate films with cylindrical nanochannels fabricated by heavy-ion-track etching

Polycarbonate films of thickness 30 μm were irradiated with heavy ions by applying a flux of 108 ions cm-2 to produce straight tracks perpendicular to the film surface. The tracks were preferentially etched in 6 M aqueous solution of sodium hydroxide to prepare cylindrical nanochannels. The channel diameters were tuned between 200 and 600 nm by varying the etching time. Co81Cu19 alloy nanowires were electrodeposited potentiostatically, while Co/Cu multilayered nanowires, consisting of alternating Co and Cu layers with thickness 10 nm, were synthesized by means of a pulse plating technique in channels of length 30 μm and diameter 200 nm. Co81Cu19 alloy nanowires showed an anisotropic magnetoresistance effect of 0.6%, and the giant magnetoresistance of Co/Cu multilayered nanowires reached up to 8.0%

Women’s memories of themselves on their journeys to housemother-style roles, 1945–1995

Diakonische Betriebsfamilien stellten im 20. Jahrhundert in Deutschland eine bedeutende Ressource im Hinblick auf die langfristige Betreuung von Kranken und behinderten Menschen dar. Da kaum empirisches Material zur Funktion der Hausmutter existierte, wurde untersucht, wie sich die Hausmutter-Funktion in der zweiten Hälfte des 20. Jahrhunderts in der Interaktion mit den Mitgliedern der Familie gestaltete und welche Bedeutung ihr zugeschrieben wurde. Für den vorliegenden Artikel wurden die Interviews von neun Hausmüttern verwendet. Orientiert an den Prinzipien der Grounded Theory nach Strauss und Corbin konnten im Gesamtergebnis drei Phasen beschrieben werden, welche die Hausmutter während ihrer Funktion durchlief. Mit der Kernkategorie Macht und Herrschaft stellt der vorliegende Artikel die erste Phase der Hausmutter-Funktion dar und zeigt, dass der Weg zur Hausmutter mit vielen Entbehrungen und einer Überforderung verbunden war. Hausmütter absolvierten zwar einen „Brautkurs“, jedoch fühlten sie sich besonders zu Beginn ihrer Funktion häufig überfordert und nur wenig auf die Funktion als Hausmutter vorbereitet. Die Erkenntnisse über die drei Phasen der Hausmutter-Funktion können zum gegenseitigen Verständnis von Pflegenden beitragen und verdeutlichen, dass professionelle Pflege am Beispiel von Betriebsfamilien gewachsen ist. In the twentieth century, diaconical institutional families represented a significant resource in the long-term care of sick and disabled people in Germany. As little empirical material on life in institutional families existed, a qualitative study was carried out to explore aspects of the role of the housemother in the context of their interactions with residents in the second half of the twentieth century and to find out it is importance was attached to this role. For this article nine former housemothers were interviewed using oral history interviews. The qualitative study based on grounded theory approach, following Strauss & Corbin. The phenomena of power and domination form the central category, which can then be divided into three phases of the role of the housemother. This article exclusively concentrates on the first phase: “‘Setting out as a bride’ – borrowed power and domination”. The process of becoming a housemother was accompanied by a great deal of sacrifice. Today, the role of the housemother is seen as outdated as it was based strongly on structures of power and domination. Understanding the three phases of the housemother role can contribute towards a mutual understanding of care providers and show that professional nursing care has grown out of the example of institutional families

Ionic conduction, rectification, and selectivity in single conical nanopores

Modern track-etching methods allow the preparation of membranes containing a single charged conical nanopore that shows high ionic permselectivity due to the electrical interactions of the surface pore charges with the mobile ions in the aqueous solution. The nanopore has potential applications in electrically assisted single-particle detection, analysis, and separation of biomolecules. We present a detailed theoretical and experimental account of the effects of pore radii and electrolyte concentration on the current-voltage and current-concentration curves. The physical model used is based on the Nernst-Planck and Poisson equations. Since the validity of continuum models for the description of ion transport under different voltages and concentrations is recognized as one of the main issues in the modeling of future applications, special attention is paid to the fundamental understanding of the electrical interactions between the nanopore fixed charges and the mobile charges confined in the reduced volume of the inside [email protected]

Sensing external spins with nitrogen-vacancy diamond

A single nitrogen-vacancy (NV) center is used to sense individual, as well as small ensembles of, electron spins placed outside the diamond lattice. Applying double electron–electron resonance techniques, we were able to observe Rabi nutations of these external spins as well as the coupling strength between the external spins and the NV sensor, via modulations and accelerated decay of the NV spin echo. Echo modulation frequencies as large as 600 kHz have been observed, being equivalent to a few nanometers distance between the NV and an unpaired electron spin. Upon surface modification, the coupling disappears, suggesting the spins to be localized at surface defects. The present study is important for understanding the properties of diamond surface spins so that their effects on NV sensors can eventually be mitigated. This would enable potential applications such as the imaging and tracking of single atoms and molecules in living cells or the use of NVs on scanning probe tips to entangle remote spins for scalable room temperature quantum computers

IRISS (Increasing Resilience in Surveillance Societies) FP7 European Research Project, Deliverable 4.2: Doing privacy in everyday encounters with surveillance.

The main idea of IRISS WP 4 was to analyse surveillance as an element of everyday life of citizens. The starting point was a broad understanding of surveillance, reaching beyond the narrowly defined and targeted (nonetheless encompassing) surveillance practices of state authorities, justified with the need to combat and prevent crime and terrorism. We were interested in the mundane effects of surveillance practices emerging in the sectors of electronic commerce, telecommunication, social media and other areas. The basic assumption of WP 4 was that being a citizen in modern surveillance societies amounts to being transformed into a techno-social hybrid, i.e. a human being inexorably linked with data producing technologies, becoming a data-leaking container. While this “ontological shift” is not necessarily reflected in citizens’ understanding of who they are, it nonetheless affects their daily lives in many different ways. Citizens may entertain ideas of privacy, autonomy and selfhood rooted in pre-electronic times while at the same time acting under a regime of “mundane governance”. We started to enquire about the use of modern technologies and in the course of the interviews focussed on issues of surveillance in a more explicit manner. Over 200 qualitative interviews were conducted in a way that produced narratives (stories) of individual experiences with different kinds of technologies and/or surveillance practices. These stories then were analysed against the background of theoretical hypotheses of what it means in objective terms to live in a surveillance society. We assume that privacy no longer is the default state of mundane living, but has to be actively created. We captured this with the term privacy labour. Furthermore we construed a number of dilemmas or trade-off situations to guide our analysis. These dilemmas address the issue of privacy as a state or “good” which is traded in for convenience (in electronic commerce), security (in law enforcement surveillance contexts), sociality (when using social media), mutual trust (in social relations at the workplace as well as in the relationship between citizens and the state), and engagement (in horizontal, neighbourhood watch-type surveillance relations). For each of these dilemmas we identified a number of stories demonstrating how our respondents as “heroes” in the narrative solved the problems they encountered, strived for the goals they were pursuing or simply handled a dilemmatic situation. This created a comprehensive and multi-dimensional account of the effects of surveillance in everyday life. Each of the main chapters does focus on one of these different dilemmas