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Sympathetic nervous system activation after aneurysmal subarachnoid hemorrhage (aSAH) is associated with complications and poor outcome. In this systematic review and meta-analysis, we investigate the effect of beta-blockers on outcome after aSAH. The review was prospectively registered with PROSPERO (CRD42019111784). We performed a systematic literature search of MEDLINE, EMBASE, the Cochrane Library, published conference proceedings, and abstracts. Eligible studies included both randomized controlled trials and observational studies up to October 2018, reporting the effect of beta-blocker therapy on the following outcomes in aSAH: mortality, vasospasm, delayed cerebral ischemia, infarction or stroke, cardiac dysfunction, and functional outcomes. Studies involving traumatic SAH were excluded. Citations were reviewed, and data extracted independently by two investigators using a standardized proforma. We identified 819 records with 16 studies (four were randomized controlled trials) including 6702 patients selected for analysis. Exposure to beta-blockade either before or after aSAH was associated with a significant reduction in unadjusted mortality (RR 0.63, 95% CI 0.42–0.93, p = 0.02). A significant reduction in unadjusted mortality was also seen in prospective trials of post-event beta-blockade (RR 0.51, 95% CI 0.28–0.93, p = 0.03). Statistically significant differences were not seen for other outcomes investigated. In adult patients with aSAH, beta-blocker therapy is associated with a mortality benefit. Studies are generally of a low quality with considerable clinical heterogeneity. Prospective large interventional trials with patient centered outcomes are required to validate this finding.

A comprehensive evaluation of a recently developed water-lean amine-based solvent, namely N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (2-EEMPA), has been performed to analyze its post-combustion CO2 capture performance. This evaluation comprises (1) fundamental characterization of the solvent–CO2 interaction using vapor–liquid equilibria, kinetics and viscosity measurements; (2) process characterization of the CO2 capture performance as measured in a laboratory scale continuous flow system and via Aspen Plus® simulation using a flue gas simulant; as well as (3) a full techno economic analysis of the capture process at industrial scale with corresponding projections of critical metrics. This paper summarizes the many parts of this comprehensive evaluation and shows how the various parts come together to empower validated conclusions about its process performance. Notably, it is projected that this solvent can operate at a regeneration heat rate of 2.0 GJ per tonne CO2 for post-combustion capture, and at a total cost of capture of $50.6/tonne CO2. With further process optimization significant reductions in the capture cost are predicted.

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Henry’s constants of H2S, CO2, CH4, and C2H6 in a hydrophobic solvent (HPS) consisting of 2-fluorophenethylamine (2-FPEA)/4-methoxy phenol (MePhOH)/a mixture of polyethylene glycol dibutyl ether (G...

A pulse oximeter is an optical device that monitors tissue oxygenation levels. Traditionally, these devices estimate the oxygenation level by measuring the intensity of the transmitted light through the tissue and are embedded into everyday devices such as smartphones and smartwatches. However, these sensors require prior information and are susceptible to unwanted changes in the intensity, including ambient light, skin tone, and motion artefacts. Previous experiments have shown the potential of Time-of-Flight (ToF) techniques in measurements of tissue hemodynamics. Our proposed technology uses histograms of photon flight paths within the tissue to obtain tissue oxygenation, regardless of the changes in the intensity of the source. Our device is based on a 45ps time-to-digital converter (TDC) which is implemented in a Xilinx Zynq UltraScale+ field programmable gate array (FPGA), a CMOS Single Photon Avalanche Diode (SPAD) detector, and a low-cost compact laser source. All these components including the SPAD detector are manufactured using the latest commercially available technology, which leads to increased linearity, accuracy, and stability for ToF measurements. This proof-of-concept system is approximately 10cmx8cmx5cm in size, with a high potential for shrinkage through further system development and component integration. We demonstrate preliminary results of ToF pulse measurements and report the engineering details, trade-offs, and challenges of this design. We discuss the potential for mass adoption of ToF based pulse oximeters in everyday devices such as smartphones and wearables., submitted to SPIE Photonics West 2021

BackgroundFragility analysis supplements the p-value and risk of bias assessment in the interpretation of results of randomised controlled trials. In this systematic review we determine the fragility index (FI) and fragility quotient (FQ) of randomized trials in aneurysmal subarachnoid haemorrhage.MethodsThis is a systematic review registered with PROSPERO (ID: CRD42020173604). Randomised controlled trials in adults with aneurysmal subarachnoid haemorrhage were analysed if they reported a statistically significant primary outcome of mortality, function (e.g. modified Rankin Scale), vasospasm or delayed neurological deterioration.ResultsWe identified 3809 records with 17 randomized trials selected for analysis. The median fragility index was 3 (inter-quartile range 0-5) and the median fragility quotient was 0.012 (IQR 0-0.034). Six of nineteen trial outcomes (31.6%) had an fragility index of 0. In seven trials (36.8%), the number of participants lost to follow-up was greater than or equal to the fragility index. Only 17.6% of trials are at low risk of bias.ConclusionsRandomised controlled trial evidence supporting management of aneurysmal subarachnoid haemorrhage is weaker than indicated by conventional analysis using p-values alone. Increased use of fragility analysis by clinicians and researchers could improve the translation of evidence to practice.

In this paper, we report the performance of an imaging multiple input multiple output (MIMO) visible light communication (VLC) system. The VLC transmitter consists of a two-dimensional, individually addressable Gallium Nitride micro light emitting diode (µLED) array. The receiver uses a two-dimensional avalanche photodiode (APD) array fabricated using complementary metal oxide semiconductor (CMOS). Using integrated CMOS-based LED drivers, a data rate greater than 1 Gbps was obtained at a link distance of 1 m with the system field of view (FOV) of 3.45 degree using four channels. At a reduced link distance of 0.5 m, a data rate of 7.48 Gbps was obtained using a nine channel MIMO system. This demonstrates the feasibility of compact MIMO systems which offer substantial data rates.

We demonstrate the development, performance and application of a GaN-based micro-light emitting diode array sharing a common p-electrode with individual-addressed n-electrodes. These individually-addressed n-electrodes minimize the series-resistance difference from conductive paths, and offer compatibility with n-type metal-oxide-semiconductor transistor-based drivers for faster modulation.

Objective Titin gene (TTN) mutations have been described in eight families with hereditary myopathy with early respiratory failure (HMERF). Some of the original patients had features resembling myofibrillar myopathy (MFM), arguing that TTN mutations could be a much more common cause of inherited muscle disease, especially in presence of early respiratory involvement. Methods We studied 127 undiagnosed patients with clinical presentation compatible with MFM. Sanger sequencing for the two previously described TTN mutations in HMERF (p.C30071R in the 119th fibronectin-3 (FN3) domain, and p.R32450W in the kinase domain) was performed in all patients. Patients with mutations had detailed review of their clinical records, muscle MRI findings and muscle pathology. Results We identified five new families with the p.C30071R mutation who were clinically similar to previously reported cases, and muscle pathology demonstrated diagnostic features of MFM. Two further families had novel variants in the 119th FN3 domain (p.P30091L and p.N30145K). No patients were identified with mutations at position p.32450. Conclusions Mutations in TTN are a cause of MFM, and titinopathy is more common than previously thought. The finding of the p.C30071R mutation in 3.9% of our study population is likely due to a British founder effect. The occurrence of novel FN3 domain variants, although still of uncertain pathogenicity, suggests that other mutations in this domain may cause MFM, and that the disease is likely to be globally distributed. We suggest that HMERF due to mutations in the TTN gene be nosologically classified as MFM-titinopathy.

Design details and characterization results of an integrated digital to light converter (DLC) for short range visible light communication (VLC) is reported. The integrated DLC can generate 16 light intensity levels at fast switching speeds, up to 500 MHz, thus enabling fast intensity modulated VLC. Data rates up to 365 Mb/s are achieved with bit error rate (BER) $1\times 10^{-3}$ at a link distance of 5 cm and an average electrical power efficiency of 70%. Optimization in the micro light emitting diode ( $\mu $ LED) manufacturing process has resulted in approximately threefold increase in data rate of the system. Spectrally efficient modulation schemes such as orthogonal frequency division multiplexing (OFDM) and pulse amplitude modulation (PAM) are also demonstrated using this integrated system.

We report the experimental realization of a 100 Mb/s wavelength division multiplexing link using commercial visible LED sources and a triple-junction photo-diode receiver. This is the first demonstration where multiple-junction technology is used for Visible Light Communication, showing its potential as a compact wavelength-selective transceiver.

We demonstrate an optical link operating in indoor ambient lighting conditions using a CMOS single photon avalanche diode (SPAD) optical receiver and a RGB light emitting diode (LED). The high sensitivity of the SPAD receiver allows the link to operate at 2 m distance at a total 60 Mb/s and bit error rate (BER) of 1×10−3 without lensing. The transmitter implements color shift keying (CSK) using a custom 4-channel current mode CMOS digital to analog converter (DAC). The miniaturized, low cost components employed at transmitter and receiver are suited to integration in portable electronic devices or chip-in-a-bulb respectively.

Concerns about climate change have propelled research efforts to develop affordable and environmentally benign technologies to capture CO2 from large emission sources, which can subsequently be used either for enhanced oil recovery or stored in other geological storage sites. The study of the solubility of CO2 in solvents is therefore of great interest, both from the theoretical and practical points of view. To screen solvents or to design CO2 capture processes, knowledge of the equilibrium solubility of CO2 in the solvents is necessary. A large body of solubility data of CO2 in aqueous and non-aqueous solutions of prominent industrial amines are available in literature. We present such data along with a description of the experimental techniques and thermodynamic models used. Innovations made to obtain an optimum solubility of CO2 and to minimize the energy cost of a desired CO2 capture system by adopting different kinds of solvents are also reviewed.

In a wireline network, nodes form links with only those nodes they are wired to, and the links do not interfere with one another. In contrast, in a wireless network, signal transmissions are intrinsically broadcast, and suffer from mutual interference. In several physical layer technologies, a wireless signal is decoded by treating the sum of all the other on-going signal transmissions as noise. Hence, from a networking standpoint, there is a need to model wireless channel interference. An accurate interference model is especially important in a multi-hop network context, since there could be several simultaneous wireless transmissions. Several works in the literature have made use of simplified interference models. Some works assume a fixed range for communication and interference, while others are based on concepts like capture threshold where the desired signal strength is compared with interference from a single node at a time, rather than cumulatively. In particular, the latter model is used in ns2 which is the most common simulation tool. Under isotropic pathloss, the capture threshold model is also equivalent to the protocol model proposed by Gupta and Kumar, which is now the subject of a lot of analytical activity notably through conflict graph based problem formulations. We investigate the accuracy and appropriateness of the capture threshold based interference model, by comparing it with one based on the SINR (signal-to-interference-and-noise ratio) with additive interference calculation. We find that both in the case of random access networks, as well as in the case of scheduled networks (where node transmissions are scheduled to be completely conflict-free), a simplified interference model such as the capture threshold model, can produce significantly different results compared to an additive interference based model. Therefore, a lot of caution should be exercised before accepting or interpreting results based on simplified interference models.

In this paper, we address the following two questions concerning the capacity and configuration of fixed wireless networks: (i) given a set of wireless nodes with arbitrary but fixed locations, and a set of data flows, what is the max-min achievable throughput? and (ii) how should the network be configured to achieve the optimum? We consider these questions from a networking standpoint assuming point-to-point links, and employ a rigorous physical layer model to model conflict relationships between them. Since we seek capacity results, we assume that the network is operated using an appropriate schedule of conflict-free link activations. We develop and investigate a novel optimization framework to determine the optimal throughput and configuration, i.e., flow routes, link activation schedules and physical layer parameters. Determining the optimal throughput is a computationally hard problem, in general. However, using a smart enumerative technique we obtain numerical results for several different scenarios of interest. We obtain several important insights into the structure of the optimal routes, schedules and physical layer parameters. Besides determining the achievable throughput, we believe that our optimization-based framework can also be used as a tool, for configuring scheduled wireless networks, such as those based on IEEE 802.16.

In this paper an energy efficient light emitting diode (LED) driver circuit for visible light communications (VLC) and results from the electrical and optical characterization are presented. A current steering digital to analogue converter (DAC) based LED driver circuit supporting 4-channels with an 8-bit resolution is realized in a 0.18 µm complimentary metal oxide semiconductor (CMOS) technology. Each channel delivers a full-scale current of 255 mA and achieves up to 67% electrical efficiency when driving 250 MS/s orthogonal frequency division multiplexing (OFDM) signals. Optical differential drive capability is demonstrated by using two output branches of a single channel to drive two different LEDs with an SNR improvement (>5 dB). The chip is also capable of full digital control of color shift keying (CSK) using multi-color LEDs enabling lighting color-temperature adjustment, dimming and multiple-input and multiple-output (MIMO) optical communications and these aspects will be the subject of future research.

Visible light communications (VLC) has the potential toplay a major part in future smart home and next generationcommunication networks. There is significant ongoing work toincrease the achievable data rates using VLC, to standardize it andintegrate it within existing network infrastructures.The future of VLC systems depends on the ability to fabricate lowcost transceiver components and to realize the promise of high datarates. This paper reports the design and fabrication of integratedtransmitter and receiver components. The transmitter uses a twodimensional individually addressable array of microlight emittingdiodes (μLEDs) and the receiver uses an integratedphotodiode arrayfabricated in a CMOS technology. A preliminary result of a MIMOsystem implementation operating at a data rate of ~1Gbps isdemonstrated. This paper also highlights the challenges in achievinghighly parallel data communication along with the possiblebottlenecks in integrated approaches

Solid state lighting systems typically use multiple Light Emitting Diode (LED) die within a single lamp, and multiple lamps within a coverage space. This infrastructure forms the transmitters for Visible Light Communications (VLC), and the availability of low-cost detector arrays offers the possibility of building Multiple Input Multiple Output (MIMO) transmission systems. Different approaches to optical MIMO are being investigated as part of a UK government funded research programme, ‘Ultra-Parallel Visible Light Communications’ (UPVLC). In this paper we present a brief review of the area and report results from systems that use integrated subsystems developed as part of the project. The scalability of these approaches and future directions will also be discussed.

We propose an address-light, integrated MAC and routing protocol (abbreviated AIMRP) for wireless sensor networks (WSNs). Due to the broad spectrum of WSN applications, there is a need for protocol solutions optimized for specific application classes. AIMRP is proposed for WSNs deployed for detecting rare events which require prompt detection and response. AIMRP organizes the network into concentric tiers around the sink(s), and routes event reports by forwarding them from one tier to another, in the direction of (one of) the sink(s). AIMRP is address-light in that it does not employ unique per-node addressing, and integrated since the MAC control packets are also responsible for finding the next-hop node to relay the data, via an anycast query. For reducing the energy expenditure due to idle-listening, AIMRP provides a power-saving algorithm which requires absolutely no synchronization or information exchange. We evaluate AIMRP through analysis and simulations, and compare it with another MAC protocol proposed for WSNs, S-MAC. AIMRP outperforms S-MAC for event-detection applications, in terms of total average power consumption, while satisfying identical sensor-to-sink latency constraints.

Summary Multi-hop wireless networks arise in the context of ad hoc networks, sensor networks, and mesh networks, and their performance depends critically on the underlying medium access control (MAC) protocol. Inspite of the large body of work devoted to MAC protocols and associated problems, the relative importance of these problems is still not well understood. This is because most of the previous work focuses on designing a protocol to solve a particular problem, or on identifying scenarios where a protocol will not work well. In addition, most of the work is also based on simplistic assumptions about the physical wireless medium, like fixed ranges for communication and interference, or concepts like capture threshold where the desired signal strength is compared with interference from a single node at a time, rather than cumulatively. Our paper seeks to address these issues. We believe it is extremely critical that (i) we develop an understanding of the relative significance of the problems affecting MAC protocols, and that (ii) we use a realistic model for the physical channel for design and performance evaluation. Towards this end, we evaluate the performance of three currently proposed MAC protocols, IEEE 802.11 [1], RI-BTMA [2], and DUCHA [3] under a realistic channel model with additive interference. Since these protocols solve or suffer from different sets of problems, our evaluation provides a differential diagnosis of the severity of these problems. Based on our observations, we propose a simple and robust two channel MAC protocol (entitled 2CM) that is based on IEEE 802.11 augmented with a busy-tone channel. The 2CM protocol (i) mitigates the hidden node problem considerably, (ii) does not waste bandwidth in terms of logical control channels, and (iii) provides a reliable link layer acknowledgment. Through extensive simulations, we show that 2CM offers a consistently high throughput performance while not sacrificing link layer reliability in a variety of scenarios, thereby vindicating our approach. Copyright © 2006 John Wiley & Sons, Ltd.

Multiple-input multiple-output (MIMO) transmission can be used to increase the throughput of visible light communication (VLC) systems. This approach is highly compatible with the use of arrays of micro light emitting diodes (μLEDs). In this work, we demonstrate an imaging-MIMO VLC system using a two dimensional individually addressable array of μLEDs and an integrated CMOS-based receiver. An aggregate data rate of −920 Mbps is realized using four parallel channels at a link distance of 1 m. Further improvement in the data rates is feasible by optimizing the system components and operating conditions.

Aims: The underlying mechanisms of migraine remain poorly understood, partly because we lack objective methods for quantitative analysis of neurological function. To address this issue, we measured interictal saccadic latency in migraineurs and controls. Methods: In a cross-sectional study, we compared interictal saccadic latency distributions of 12,800 saccades in 32 migraineurs with 32 age- and sex-matched controls. Results: The variability of migraineurs’ reaction time distributions was significantly smaller (σ = 1.01 vs. 1.13; p Conclusions: The migraineur’s brain behaves significantly differently from that of a control during the interictal period. By analysing whole distributions, rather than just means, data can be related directly to current neurophysiological models: specifically, the observed decrease in variability suggests a functional deficit in the noradrenergic systems influencing the cerebral cortex. From a clinical perspective, this novel method of characterising neurological function in migraine is more rapid, practicable, inexpensive, objective and quantitative than previous methods such as evoked potentials and transcranial magnetic stimulation, and has the potential both to improve current diagnostic discrimination and to help guide future research into the underlying neural mechanisms.

Digital signatures are one of the fundamental security primitives in Vehicular Ad-Hoc Networks (VANETs) because they provide authenticity and non-repudiation in broadcast communication. However, the current broadcast authentication standard in VANETs is vulnerable to signature flooding: excessive signature verification requests that exhaust the computational resources of victims. In this paper, we propose two efficient broadcast authentication schemes, Fast Authentication (FastAuth) and Selective Authentication (SelAuth), as two countermeasures to signature flooding. FastAuth secures periodic single-hop beacon messages. By exploiting the sender's ability to predict its own future beacons, FastAuth enables 50 times faster verification than previous mechanisms using the Elliptic Curve Digital Signature Algorithm. SelAuth secures multi-hop applications in which a bogus signature may spread out quickly and impact a significant number of vehicles. SelAuth pro- vides fast isolation of malicious senders, even under a dynamic topology, while consuming only 15%--30% of the computational resources compared to other schemes. We provide both analytical and experimental evaluations based on real traffic traces and NS-2 simulations. With the near-term deployment plans of VANET on all vehicles, our approaches can make VANETs practical.

Kimura’s disease is a rare, benign, slow-growing chronic inflammatory swelling with a predilection for the head and neck region and almost always with peripheral blood eosinophilia and elevated serum IgE levels. Here, we report a 14-year-old male patient with left-sided cheek swelling. It was painless swelling situated anterior to left ear, of 1 year duration, without any other symptoms. Routine investigations were inconclusive. Excision biopsy revealed the diagnosis of Kimura’s disease.

We propose a security model for Vehicular Ad-hoc Networks (VANETs) to distinguish spurious messages from legitimate messages. In this paper, we explore the information available in a VANET environment to enable vehicles to filter out malicious messages which are transmitted by a minority of misbehaving vehicles. More specifically, we introduce a message filtering model that leverages multiple complementary sources of information to construct a multi-source detection model such that drivers are only alerted after some fraction of sources agree. Our filtering model is based on two main components: a threshold curve and a Certainty of Event (CoE) curve. A threshold curve implies the importance of an event to a driver according to the relative position, and a CoE curve represents the confidence level of the received messages. An alert is triggered when the event certainty surpasses a threshold. We analyze our model and provide some initial simulation results to demonstrate the benefits.

High throughput and lifetime are both crucial design objectives for a number of multihop wireless network applications. As these two objectives are often in conflict with each other, it naturally becomes important to identify the trade-offs between them. Several works in the literature have focused on improving one or the other, but investigating the trade-off between throughput and lifetime has received relatively less attention. We study this trade-off between the network throughput and lifetime for the case of fixed wireless networks, where link transmissions are coordinated to be conflict-free. We employ a realistic interference model based on the Signal-to-Interference-and-Noise Ratio (SINR), which is usually considered statistically sufficient to infer success or failure of wireless transmissions. Our analytical and numerical results provide several insights into the interplay between throughput, lifetime, and transmit power. Specifically, we find that with a fixed throughput requirement, lifetime is not monotonic with power-neither very low power nor very high power result in the best lifetime. We also find that, for a fixed transmit power, relaxing the throughput requirement may result in a more than proportional improvement in the lifetime for small enough relaxation factors. Taken together, our insights call for a careful balancing of objectives when designing a wireless network for high throughput and lifetime. Accepted version

Efficient broadcast authentication has seen a lot of work in the recent past. Most broadcast authentication protocols rely on an underlying Public Key Infrastructure (PKI) to provide a point of trust from which credentials for more efficient cryptographic mechanisms for broadcast authentication can be derived. Thus, there is a logical dependence of some cryptographic credentials (e.g., verifiers for one-time signatures) on others (e.g., certificates from the PKI). However, since V2V messages are transmitted using a random access broadcast, messages containing these credentials could be lost, thereby preventing the verification of credentials depending on the lost ones. Further, since the wireless bandwidth is precious, there have been proposals to optimize the transmission of certificates and other credentials over the air. The more infrequently these are transmitted, the more is the temporal dependence on the verification times of V2V messages. On the flip side, the more frequently these are transmitted, the more is the bandwidth overhead (i.e., greater packet size) and the more the chances of packet collisions over the air. We illustrate this dilemma by means of a case-study, and advocate a holistic approach to broadcast authentication.

Safety applications aim to avoid vehicular accidents, by providing advisories to the driver, by using secure broadcast vehicle-to-vehicle (V2V) communications. However, any security mechanism used for authenticating broadcast V2V messages, comes with overheads in terms of computation, storage and communications. Further due to the resource-constrained computing platforms used in the automotive domain, these overheads could translate into performance bottlenecks. Prior works related to performance modeling of secure V2V communications do not consider the computational overheads of security, since traditionally packet transmission rather than packet processing is taken to be the bottleneck. This paper provides an evaluation of the performance of secure V2V communications, while explicitly modeling the computational and storage overheads due to security. We observe that there is a complex coupling between the security and the communication layers, and that the performance bottlenecks could shift from one to the other depending on the system parameters. In order to explain these observations, we propose a fixed point based approach which essentially assumes the two layers at a given node independent from each other and from those at other nodes, and uses the inherent consistency relationships to yield fixed point equations for performance metrics such as blocking or collision probability. Our results indicate that this is a promising approach which works quite accurately.

Scheduled wireless mesh networks (WMNs) represent an important paradigm in the development of high speed wireless access networks. As a consequence of (Aditya Karnik, 2006), it can be shown that the maximum throughput of a single gateway n node WMN is upper-bounded by 1/n, normalized with respect to the highest available data-rate. The situation is actually worse since with conventional omni-directional antennas, the achievable throughput is considerably lower at low powers. This paper makes a case for smart (directional) antennas. For the same power, smart antennas can provide higher range, and therefore shorter paths, as compared to omni-directional antennas. For the same range, smart antennas can operate at lower powers, reducing the interference, and thereby improving the spatial reuse. Although they cannot change the fundamental throughput limit of 1/n, smart antennas can achieve significantly higher throughput at lower powers, These insights are demonstrated through several numerical examples using the framework of (Aditya Karnik, 2006).

The problem of connectivity in multi-hop wireless networks has been extensively studied in the literature and general results for node density requirements have been obtained (P. Gupta and P.R. Kumar, Proc. 37th IEEE Conf. of Decision and Control, 1998). These results have been obtained based on the implicit assumption of a generic routing protocol, capable of exhaustively searching all possible routes, between all pairs of nodes. Hence these results would be too optimistic in several practical cases, where the routing protocols are not generic but optimized for specific applications. In this paper, we provide a framework for defining the appropriate notion of connectivity that reflects the underlying network architecture and protocols. Based on this framework, we define and analyze connectivity requirements for two network architectures proposed in the literature, namely, GAF (geographic adaptive fidelity) with Manhattan routing (Y. Xu et al., Proc. Int. Conf. on Mobile Comp. and Netw., 2001), proposed for ad-hoc networks and AIMRP (address-light integrated MAC and routing protocol) which employs tier-based routing in sensor networks (S.S. Kulkarni et al., submitted for publication in IEEE Trans. on Networking, Dec. 2003). By comparing the critical node density requirements for connectivity, obtained through our framework, with the results in Gupta and Kumar, we show that the earlier results are too optimistic and hence it is important to consider the underlying routing protocol to dimension the density of nodes appropriately.

We analysed positive respiratory isolates for antibiotic resistance in our out-of-hospital cardiac arrest (OOHCA) population to establish adequacy of current empirical regimes. Pneumonia commonly complicates OOHCA, with studies suggesting a prevalence up to 48% [1].

Titin gene (TTN) mutations have been described in 8 families with hereditary myopathy with early respiratory failure (HMERF) a rare condition with features resembling myofibrillar myopathy (MFM). In order to verify if TTN mutations could be a cause of MFM, especially in presence of early respiratory involvement, we carried out a clinical and genetic analysis of 127 undiagnosed patients with a clinical presentation compatible with MFM. Sanger sequencing for the TTN mutations previously described in patients with HMERF (p.C30071R and p.R32450W) was performed in all patients. We identified 5 families with the p.C30071R mutation (3.9% of study population) likely due to a British founder effect. Affected subjects showed phenotypic features similar to previously reported cases, and muscle pathology demonstrated diagnostic features of MFM. Two further families had novel variants in the 119th FN3 domain (p.P30091L and p.N30145K). Although still with uncertain pathogenicity, these new variants suggest that other TTN mutations in this domain may cause MFM. Our results indicate that mutations in TTN gene cause MFM and titinopathy is more common than previously thought. We suggest that HMERF due to mutations in the TTN gene be nosologically classified as MFM-titinopathy.