Improvements to data transportation security in wireless sensor networks

Wireless Sensor Networks (WSNs) are computer networks consisting of miniaturisedelectronic devices that aim to gather and report information about their environment. Thedevices are limited in computational, data storage and communication ability. Furthermore,the devices communicate via a wireless, unregulated medium and usually operate on finitepower sources. Security in Wireless Sensor Networks is the research area that seeks toprovide adequate and energy-efficient security mechanisms for WSNs. Such provision isrequired in order to increase their range of possible applications and allow them to bedeployed in critical and valuable environments. Existing security mechanisms for largercomputer networks are inappropriate since they were not designed for the resourceconstrainedenvironment of WSNs. There are some purpose-built solutions but this researchhas found potential security or efficiency problems with each of them.This thesis contributes SecRose, a security mechanism for the data-transportation layer ofWireless Sensor Networks. The solution attempts to provide higher level of security thancurrently provided, without introduction of significant energy overheads and by retainingbackwards compatibility. SecRose achieves its security objectives by introducing a number ofinnovations and improvements.SecRose innovates in the provision of freshness and semantic security by altering the secretcryptographic keys. The process is managed at the transportation level by the basic keymanagement mechanism. The integrity and safety of the key-changing operation is achievedby authenticating all packets and their acknowledgements. This behaviour contrasts with otherproposals, which are based on openly transmitted Initialisation Vectors, and allows SecRoseto provide better security than most of them, including TinySec, the accepted standard.In addition, measurements show that SecRose provides better energy-efficiency than otherproposals. In particular, the solution requires less energy than TinySec in all cases and it caneven be more efficient than the base Operating System, the TinyOS, which does not provideany security at all

An Integrated Cloud-based Healthcare Infrastructure

Abstract—We present a cloud-based healthcare system that integrates a formal care system (DACAR) with an informal care system (Microsoft HealthVault). The system provides high levels of security and privacy within a cloud environment, enabling sharing of both health records and the access rights, along the patient pathway. We also define a case study that can help in evaluating and in demonstrating the usefulness of a cloud-based integrated health care system

ATP signalling in epilepsy

This paper focuses on a role for ATP neurotransmission and gliotransmission in the pathophysiology of epileptic seizures. ATP along with gap junctions propagates the glial calcium wave, which is an extraneuronal signalling pathway in the central nervous system. Recently astrocyte intercellular calcium waves have been shown to underlie seizures, and conventional antiepileptic drugs have been shown to attenuate these calcium waves. Blocking ATP-mediated gliotransmission, therefore, represents a potential target for antiepileptic drugs. Furthermore, while knowledge of an antiepileptic role for adenosine is not new, a recent study showed that adenosine accumulates from the hydrolysis of accumulated ATP released by astrocytes and is believed to inhibit distant synapses by acting on adenosine receptors. Such a mechanism is consistent with a surround-inhibitory mechanism whose failure would predispose to seizures. Other potential roles for ATP signalling in the initiation and spread of epileptiform discharges may involve synaptic plasticity and coordination of synaptic networks. We conclude by making speculations about future developments

Neuroprotection by adenosine in the brain: From A1 receptor activation to A2A receptor blockade

Adenosine is a neuromodulator that operates via the most abundant inhibitory adenosine A1 receptors (A1Rs) and the less abundant, but widespread, facilitatory A2ARs. It is commonly assumed that A1Rs play a key role in neuroprotection since they decrease glutamate release and hyperpolarize neurons. In fact, A1R activation at the onset of neuronal injury attenuates brain damage, whereas its blockade exacerbates damage in adult animals. However, there is a down-regulation of central A1Rs in chronic noxious situations. In contrast, A2ARs are up-regulated in noxious brain conditions and their blockade confers robust brain neuroprotection in adult animals. The brain neuroprotective effect of A2AR antagonists is maintained in chronic noxious brain conditions without observable peripheral effects, thus justifying the interest of A2AR antagonists as novel protective agents in neurodegenerative diseases such as Parkinson’s and Alzheimer’s disease, ischemic brain damage and epilepsy. The greater interest of A2AR blockade compared to A1R activation does not mean that A1R activation is irrelevant for a neuroprotective strategy. In fact, it is proposed that coupling A2AR antagonists with strategies aimed at bursting the levels of extracellular adenosine (by inhibiting adenosine kinase) to activate A1Rs might constitute the more robust brain neuroprotective strategy based on the adenosine neuromodulatory system. This strategy should be useful in adult animals and especially in the elderly (where brain pathologies are prevalent) but is not valid for fetus or newborns where the impact of adenosine receptors on brain damage is different

Inactivation of Listeria monocytogenes in raw and hot smoked trout fillets by high hydrostatic pressure processing combined with liquid smoke and freezing

High hydrostatic pressure (HHP; 200 MPa for 15 min), liquid smoke (0.50%, v/v) and freezing (−80 °C, overnight) was used to eliminate Listeria monocytogenes in BHI broth, raw and smoked trout. The bactericidal effect of liquid smoke solutions (L9 and G6), HHP and their combinations was evaluated against L. monocytogenes LO28, EGD-e and 10403S and further continued with the most resistant strain (10403S) to the combined treatment. For first time, a synergistic effect of liquid smoke and HHP was observed and was further enhanced by freezing prior to HHP. The effect of HHP and liquid smoke, prior to freezing was highest in BHI compared to raw and smoked trout. A major synergistic effect of HHP, liquid smoke and freezing was observed, reaching a 5.48 or 1.93 log CFU/g reduction when smoked or raw trout was used respectively. Furthermore, high injury levels occurred, among treatments reaching up to 55.98%

A review of techniques to counter spam and spit

This paper studies the most important techniques with which to challenge the problem of unsolicited e-mails (spam) and unsolicited messages in Internet telephony (spit). First an introduction to the problem of spam demonstrates the importance (economic and technological) of finding a solution. Then we analyze the most important techniques that exist to counter the problem. After that we concentrate on a new problem: spam using new internet telephony technologies (spit). This problem, even if existing only theoretically until now, very soon will be one of the main factors affecting the broad use of VoIP. We analyze the most important methods and techniques of countering spit. Finally, we mentione differences between spam and spit and state some useful conclusions. © 2009 Springer Science+Business Media, LLC