Treponema denticola in Disseminating Endodontic Infections

Treponema denticola is a consensus periodontal pathogen that has recently been associated with endodontic pathology. In this study, the effect of mono-infection of the dental pulp with T. denticola and with polymicrobial “red-complex” organisms (RC) (Porphyromonas gingivalis, Tannerella forsythia, and T. denticola) in inducing disseminating infections in wild-type (WT) and severe-combined-immunodeficiency (SCID) mice was analyzed. After 21 days, a high incidence (5/10) of orofacial abscesses was observed in SCID mice mono-infected with T. denticola, whereas abscesses were rare in SCID mice infected with the red-complex organisms or in wildtype mice. Splenomegaly was present in all groups, but only mono-infected SCID mice had weight loss. T. denticola DNA was detected in the spleen, heart, and brain of mono-infected SCID mice and in the spleen from mono-infected wild-type mice, which also had more periapical bone resorption. The results indicate that T. denticola has high pathogenicity, including dissemination to distant organs, further substantiating its potential importance in oral and linked systemic conditions

A hybrid modulation for the dissemination of weather data to aircraft

Ohio University is continuing to conduct research to improve its system for weather data dissemination to aircraft. The current experimental system transmit compressed weather radar reflectivity patterns from a ground based station to aircraft. Although an effective system, the limited frequency spectrum does not provide a channel for transmission. This introduces the idea of a hybrid modulation. The hybrid technique encodes weather data using phase modulation (PM) onto an existing aeronautical channel which employs amplitude modulation (AM) for voice signal transmission. Ideally, the two modulations are independent of one another. The planned implementation and basis of the system are the reviewed

Amorphous Placement and Informed Diffusion for Timely Monitoring by Autonomous, Resource-Constrained, Mobile Sensors

Personal communication devices are increasingly equipped with sensors for passive monitoring of encounters and surroundings. We envision the emergence of services that enable a community of mobile users carrying such resource-limited devices to query such information at remote locations in the field in which they collectively roam. One approach to implement such a service is directed placement and retrieval (DPR), whereby readings/queries about a specific location are routed to a node responsible for that location. In a mobile, potentially sparse setting, where end-to-end paths are unavailable, DPR is not an attractive solution as it would require the use of delay-tolerant (flooding-based store-carry-forward) routing of both readings and queries, which is inappropriate for applications with data freshness constraints, and which is incompatible with stringent device power/memory constraints. Alternatively, we propose the use of amorphous placement and retrieval (APR), in which routing and field monitoring are integrated through the use of a cache management scheme coupled with an informed exchange of cached samples to diffuse sensory data throughout the network, in such a way that a query answer is likely to be found close to the query origin. We argue that knowledge of the distribution of query targets could be used effectively by an informed cache management policy to maximize the utility of collective storage of all devices. Using a simple analytical model, we show that the use of informed cache management is particularly important when the mobility model results in a non-uniform distribution of users over the field. We present results from extensive simulations which show that in sparsely-connected networks, APR is more cost-effective than DPR, that it provides extra resilience to node failure and packet losses, and that its use of informed cache management yields superior performance

Structural characterisation of outer membrane proteins from Borrelia burgdorferi sensu lato by small-angle X-ray scattering

Forming the interface between the bacterial cell and the host, the outer membrane of Borrelia is known to play a key role in pathogenicity. Although Borrelia burgdorferi sensu lato are considered to be Gram-negative, their outer membrane is unique, lacking liposaccharides and phosphatidylethanolamine. It contains a variety of glycolipids, surface exposed lipoproteins and a number of membrane-spanning β-barrels. BAPKO_0422, BB_0562 and BG_0408 are membrane proteins, theoretically predicted to form 8-stranded, membrane-spanning β-barrels. The aim of this work is to produce recombinant versions of these proteins, and determine molecular envelopes by small-angle X-ray scattering (SAXS). The β-barrel model can then be tested by comparing the experimental molecular envelope with the theoretical predictions. Three Borrelia proteins (BAPKO_0422, BB_0562 and BG_0408) were recombinantly expressed in the E. coli expression system using the pET-47 expression vector. The putative membrane proteins were purified by immobilised metal affinity chromatography (IMAC). The His tag of BAPKO_0422 was enzymatically removed to produce a native protein, and to allow for a visual comparison of the protein both with and without the His tag. SAXS data for each protein were collected and the overall shape was determined using ab initio methods. The pair-distance distribution function (P(r) function) of BAPKO_0422 with the His tag indicated a particle overlap potentially caused by the flexible 6-His tag at the N-terminus. Kratky plots of BAPKO_0422, BB_0562 and BG_0408 revealed the parabolic convergence for a folded particle. The low-resolution molecular envelopes of BAPKO_0422, BB_0562 and BG_0408 are consistent with the structure of an 8-stranded β-barrel. The filtered envelopes are in agreement with the shape and size of the E. coli homologue OmpX. The likely orientation of the protein within the outer membrane can be deduced by comparing molecular envelopes with and without the N-terminal His tag. The data suggest that BAPKO_0422, BB_0562 and BG_0408 are single-domain cylindrical-shaped molecules with no evidence of an internal pore. Several questions remain to be answered, such as the oligomeric state of BG_0408 and BAPKO_0422. The function of these 8-stranded β-barrels in the Borrelial outer membrane remains to be investigated

Smart Embedded Passive Acoustic Devices for Real-Time Hydroacoustic Surveys

This paper describes cost-efficient, innovative and interoperable ocean passive acoustics sensors systems, developed within the European FP7 project NeXOS (Next generation Low-Cost Multifunctional Web Enabled Ocean Sensor Systems Empowering Marine, Maritime and Fisheries Management) These passive acoustic sensors consist of two low power, innovative digital hydrophone systems with embedded processing of acoustic data, A1 and A2, enabling real-time measurement of the underwater soundscape. An important part of the effort is focused on achieving greater dynamic range and effortless integration on autonomous platforms, such as gliders and profilers. A1 is a small standalone, compact, low power, low consumption digital hydrophone with embedded pre-processing of acoustic data, suitable for mobile platforms with limited autonomy and communication capability. A2 consists of four A1 digital hydrophones with Ethernet interface and one master unit for data processing, enabling real-time measurement of underwater noise and soundscape sources. In this work the real-time acoustic processing algorithms implemented for A1 and A2 are described, including computational load evaluations of the algorithms. The results obtained from the real time test done with the A2 assembly at OBSEA observatory collected during the verification phase of the project are presented.Postprint (author's final draft

Stratigraphy, age, composition, and correlation of late Quaternary tephras interbedded with organic sediments in Waikato lakes, North Island, New Zealand

Cores from 14 peaty lakes in the central Waikato region, northern North Island, contain a sequence of 41 well-preserved, mainly macroscopic, occasionally bedded, ash and lapilli layers ranging in thickness from c. 2 to 110 mm and interbedded with fine-grained organic lake sediment. The layers, whose field and compositional properties are described in detail, are distal airfall tephras that were erupted between c. 17000 and c. 1800 ¹⁴C years ago from six rhyolitic and andesitic volcanic centres located c. 70-200 km from the Waikato sites: Taupo (5 tephras), Okataina (7), Maroa (1) (rhyolitic); Mayor Island (2) (peralkaline); Tongariro (11), and Egmont (15) (andesitic)

Cascaded multiplexed optical link on a telecommunication network for frequency dissemination

We demonstrate a cascaded optical link for ultrastable frequency dissemination comprised of two compensated links of 150 km and a repeater station. Each link includes 114 km of Internet fiber simultaneously carrying data traffic through a dense wavelength division multiplexing technology, and passes through two routing centers of the telecommunication network. The optical reference signal is inserted in and extracted from the communication network using bidirectional optical add-drop multiplexers. The repeater station operates autonomously ensuring noise compensation on the two links and the ultra-stable signal optical regeneration. The compensated link shows a fractional frequency instability of 3 \times 10-15 at one second measurement time and 5 \times 10-20 at 20 hours. This work paves the way to a wide dissemination of ultra-stable optical clock signals between distant laboratories via the Internet network