UK Food Standards Agency Workshop Report: Diet and Immune Function

The UK Food Standards Agency convened a workshop on 13 May 2009 to discuss recently completed research on diet and immune function. The objective of the workshop was to review this research and to establish priorities for future research. Several of the trials presented at the workshop showed some effect of nutritional interventions (e.g. vitamin D, Zn, Se) on immune parameters. One trial found that increased fruit and vegetable intake may improve the antibody response to pneumococcal vaccination in older people. The workshop highlighted the need to further clarify the potential public health relevance of observed nutrition-related changes in immune function, e.g. susceptibility to infections and infectious morbidity.

UK Food Standards Agency Workshop Report: carbohydrate and cardiovascular risk

This report summarises a workshop convened by the UK Food Standards Agency (FSA) on 14 October 2008 to discuss current FSA-funded research on carbohydrates and cardiovascular health. The objective of this workshop was to discuss the results of recent research and to identify any areas which could inform future FSA research calls. This workshop highlighted that the FSA is currently funding some of the largest, well-powered intervention trials investigating the type of fat and carbohydrate, whole grains and fruit and vegetables, on various CVD risk factors. Results of these trials will make a substantive contribution to the evidence on diet and cardiovascular risk.

Inherited defects in pedigree dogs. Part 2: Disorders that are not related to breed standards

Recent debate concerning health problems in pedigree animals has highlighted gaps in current knowledge of the prevalence, severity and welfare implications of deleterious inherited traits within the pedigree dog population. In this second part of a two-part review, inherited disorders in the top 50 UK Kennel Club registered breeds were researched using systematic searches of existing databases. A set of inclusion and exclusion criteria, including an evidence strength scale (SEHB), were applied to search results. A total of 312 non-conformation linked inherited disorders was identified, with German shepherd dogs and Golden retrievers associated with the greatest number of disorders. The most commonly reported mode of inheritance was autosomal recessive (71%; 57 breed-disorder combinations), and the most common primarily affected body system was the nervous sensory system. To provide a true assessment of the scale of inherited disorders in the pedigree dogs studied more effort is required to collect accurate prevalence data.

QR decomposition-based matrix inversion for high performance embedded MIMO receivers

Real-time matrix inversion is a key enabling technology in multiple-input multiple-output (MIMO) communications systems, such as 802.11n. To date, however, no matrix inversion implementation has been devised which supports real-time operation for these standards. In this paper, we overcome this barrier by presenting a novel matrix inversion algorithm which is ideally suited to high performance floating-point implementation. We show how the resulting architecture offers fundamentally higher performance than currently published matrix inversion approaches and we use it to create the first reported architecture capable of supporting real-time 802.11n operation. Specifically, we present a matrix inversion approach based on modified squared Givens rotations (MSGR). This is a new QR decomposition algorithm which overcomes critical limitations in other QR algorithms that prohibits their application to MIMO systems. In addition, we present a novel modification that further reduces the complexity of MSGR by almost 20%. This enables real-time implementation with negligible reduction in the accuracy of the inversion operation, or the BER of a MIMO receiver based on this.

Software-defined sphere decoding for FPGA-based MIMO detection

Sphere Decoding (SD) is a highly effective detection technique for Multiple-Input Multiple-Output (MIMO) wireless communications receivers, offering quasi-optimal accuracy with relatively low computational complexity as compared to the ideal ML detector. Despite this, the computational demands of even low-complexity SD variants, such as Fixed Complexity SD (FSD), remains such that implementation on modern software-defined network equipment is a highly challenging process, and indeed real-time solutions for MIMO systems such as 4 4 16-QAM 802.11n are unreported. This paper overcomes this barrier. By exploiting large-scale networks of fine-grained softwareprogrammable processors on Field Programmable Gate Array (FPGA), a series of unique SD implementations are presented, culminating in the only single-chip, real-time quasi-optimal SD for 44 16-QAM 802.11n MIMO. Furthermore, it demonstrates that the high performance software-defined architectures which enable these implementations exhibit cost comparable to dedicated circuit architectures.

FPGA based Soft-core SIMD Processing: A MIMO-OFDM Fixed-Complexity Sphere Decoder Case Study

To enable reliable data transfer in next generation Multiple-Input Multiple-Output (MIMO) communication systems, terminals must be able to react to fluctuating channel conditions by having flexible modulation schemes and antenna configurations. This creates a challenging real-time implementation problem: to provide the high performance required of cutting edge MIMO standards, such as 802.11n, with the flexibility for this behavioural variability. FPGA softcore processors offer a solution to this problem, and in this paper we show how heterogeneous SISD/SIMD/MIMD architectures can enable programmable multicore architectures on FPGA with similar performance and cost as traditional dedicated circuit-based architectures. When applied to a 4×4 16-QAM Fixed-Complexity Sphere Decoder (FSD) detector we present the first soft-processor based solution for real-time 802.11n MIMO.

Investigation of secure wireless regions using configurable beamforming on WARP

In this paper, we examine a novel approach to network security against passive eavesdroppers in a ray-tracing model and implement it on a hardware platform. By configuring antenna array beam patterns to transmit the data to specific regions, it is possible to create defined regions of coverage for targeted users. By adapting the antenna configuration according to the intended user’s channel state information, this allows the vulnerability of the physical regions to eavesdropping to be reduced. We present the application of our concept to 802.11n networks where an antenna array is employed at the access point. A range of antenna array configurations are examined by simulation and then realized using the Wireless Open-Access Research Platform(WARP)

Creating secure wireless regions using configurable beamforming

We present a novel approach to network security against passive eavesdroppers by employing a configurable beam-forming technique to create tightly defined regions of coverage for targeted users. In contrast to conventional encryption methods, our security scheme is developed at the physical layer by configuring antenna array beam patterns to transmit the data to specific regions. It is shown that this technique can effectively reduce vulnerability of the physical regions to eavesdropping by adapting the antenna configuration according to the intended user's channel state information. In this paper we present the application of our concept to 802.11n networks where an antenna array is employed at the access point, and consider the issue of minimizing the coverage area of the region surrounding the targeted user. A metric termed the exposure region is formally defined and used to evaluate the level of security offered by this technique. A range of antenna array configurations are examined through analysis and simulation, and these are subsequently used to obtain the optimum array configuration for a user traversing a coverage area.

A review of the global pesticide legislation and the scale of challenge in reaching the global harmonization of food safety standards

Pesticide use is important in agriculture to protect crops and improve productivity. However, they have the potential to cause adverse human health or environmental effects, dependent on exposure levels. This review examines existing pesticide legislation worldwide, focusing on the level of harmonisation, and impacts of differing legislation on food safety and trade. Pesticide legislation varies greatly worldwide as countries have different requirements guidelines and legal limits for plant protection. Developed nations have more stringent regulations than developing countries, which lack the resources and expertise to adequately implement and enforce legislation. Global differences in pesticide legislation act as a technical barrier to trade. International parties such as the European Union (EU), Codex Alimentarius Commission (Codex), and North American Free Trade Agreement (NAFTA) have attempted to harmonise pesticide legislation by providing maximum residue limits (MRLs), but globally these limits remain variable. Globally harmonised pesticide standards would serve to increase productivity, profits and trade, and enhance the ability to protect public health and the environment. 

Investigating Cyber-Physical Attacks against IEC 61850 Photovoltaic Inverter Installations

Cyber-attacks against Smart Grids have been found in the real world. Malware such as Havex and BlackEnergy have been found targeting industrial control systems (ICS) and researchers have shown that cyber-attacks can exploit vulnerabilities in widely used Smart Grid communication standards. This paper addresses a deep investigation of attacks against the manufacturing message specification of IEC 61850, which is expected to become one of the most widely used communication services in Smart Grids. We investigate how an attacker can build a custom tool to execute man-in-the-middle attacks, manipulate data, and affect the physical system. Attack capabilities are demonstrated based on NESCOR scenarios to make it possible to thoroughly test these scenarios in a real system. The goal is to help understand the potential for such attacks, and to aid the development and testing of cyber security solutions. An attack use-case is presented that focuses on the standard for power utility automation, IEC 61850 in the context of inverter-based distributed energy resource devices; especially photovoltaic (PV) generators.

High Performance Real-time Pre-Processing for Fixed-Complexity Sphere Decoder

Pre-processing (PP) of received symbol vector and channel matrices is an essential pre-requisite operation for Sphere Decoder (SD)-based detection of Multiple-Input Multiple-Output (MIMO) wireless systems. PP is a highly complex operation, but relative to the total SD workload it represents a relatively small fraction of the overall computational cost of detecting an OFDM MIMO frame in standards such as 802.11n. Despite this, real-time PP architectures are highly inefficient, dominating the resource cost of real-time SD architectures. This paper resolves this issue. By reorganising the ordering and QR decomposition sub operations of PP, we describe a Field Programmable Gate Array (FPGA)-based PP architecture for the Fixed Complexity Sphere Decoder (FSD) applied to 4 × 4 802.11n MIMO which reduces resource cost by 50% as compared to state-of-the-art solutions whilst maintaining real-time performance.

IEEE C37.118-2 Synchrophasor Communication Framework

Synchrophasors have become an important part of the modern power system and numerous applications have been developed covering wide-area monitoring, protection and control. Most applications demand continuous transmission of synchrophasor data across large geographical areas and require an efficient communication framework. IEEE C37.118-2 evolved as one of the most successful synchrophasor communication standards and is widely adopted. However, it lacks a predefined security mechanism and is highly vulnerable to cyber attacks. This paper analyzes different types of cyber attacks on IEEE C37.118-2 communication system and evaluates their possible impact on any developed synchrophasor application. Further, the paper also recommends an efficent security mechanism that can provide strong protection against cyber attacks. Although, IEEE C37.118-2 has been widely adopted, there is no clear understanding of the requirements and limitations. To this aim, the paper also presents detailed performance evaluation of IEEE C37.118-2 implementations which could help determine required resources and network characteristics before designing any synchrophasor application.