Generic Architecture and Semiconductor Intellectual Property Cores for Avanced Encryption Standard Cryptography

A generic architecture for implementing the advanced encryption standard (AES) encryption algorithm in silicon is proposed. This allows the instantiation of a wide range of chip specifications, with these taking the form of semiconductor intellectual property (IP) cores. Cores implemented from this architecture can perform both encryption and decryption and support four modes of operation: (i) electronic codebook mode; (ii) output feedback mode; (iii) cipher block chaining mode; and (iv) ciphertext feedback mode. Chip designs can also be generated to cover all three AES key lengths, namely 128 bits, 192 bits and 256 bits. On-the-fly generation of the round keys required during decryption is also possible. The general, flexible and multi-functional nature of the approach described contrasts with previous designs which, to date, have been focused on specific implementations. The presented ideas are demonstrated by implementation in FPGA technology. However, the architecture and IP cores derived from this are easily migratable to other silicon technologies including ASIC and PLD and are capable of covering a wide range of modem communication systems cryptographic requirements. Moreover, the designs produced have a gate count and throughput comparable with or better than the previous one-off solutions.

Necrospermia and chronic spinal cord injury.

OBJECTIVE: To determine whether improvement in quality of semen over 4 consecutive days of electroejaculation in men with chronic spinal cord injury (SCI) was consistent with epididymal necrospermia. DESIGN: Prospective study of a random sample of men with SCI. SETTING: A southeastern Australian SCI management center in collaboration with the specialist andrology service of a university-based department of obstetrics and gynecology in a tertiary referral hospital. PATIENT(S): Nine men with chronic spinal cord injury. INTERVENTION(S): Semen samples were obtained by using electroejaculation, and testicular biopsy samples were obtained by using fine-needle tissue aspiration. MAIN OUTCOME MEASURE(S): Semen analysis was performed according to World Health Organization criteria. Testicular biopsy and electron microscopy were done by using standard techniques. RESULT(S): During up to 4 days of consecutive-day electroejaculation, sperm motility and viability in semen obtained from men with chronic SCI increased by an average of 23% on days 2 and 3. The severity of the degenerative changes and the numbers of spermatozoa affected on day 1 became less marked by day 4. The changes were not present in late spermatids obtained from testicular biopsies. CONCLUSION(S): The asthenospermia of chronic SCI is similar to epididymal necrospermia and can be improved by consecutive-day electroejaculation.

Implementing a resuscitation policy for patients at the end of life in an acute hospital setting: qualitative study

Objective : To explore attitudes and experiences of doctors and nurses regarding cardiopulmonary resuscitation for patients with end stage illness in an acute hospital. Design : Qualitative study; thematic analysis of two audio-taped focus groups and four semi-structured interviews. Setting : Acute district hospital, Northern Ireland. Participants : Seven nurses and nine doctors; varying nationality, gender and years of professional experience; involved in cardiopulmonary resuscitation decision-making. Results : Participants reported different interpretations of resuscitation policy and of what do not attempt to resuscitate (DNAR) decisions meant in relation to practical care for patients. This confusion in translating policy into practice contributed to communication difficulties in initiating, documenting and implementing cardiopulmonary resuscitation decisions. Participants were aware of how clinical conditions could change and reported uncertainty in determining end stage illness; they expressed fears of potential consequences of DNAR decisions for patients' care. The more disease-centred approach of doctors to patients' management, compared to nurses' more patient-centred approach, contributed to inter-professional conflict within teams. Doctors identified training needs in applying resuscitation policy and ethical principles in `real life' and nurses identified a need for ongoing professional support, which was perceived as being less available to junior doctors. Personal relationships between staff and patients, cultural reluctance to address sensitive issues and local community expectations of relatives being involved in decisions added to policy implementation difficulties. Conclusions : The findings indicate a need for ongoing staff support and training in applying resuscitation policy to decisions for patients with end stage illness in an acute hospital. They support suggestions that reviews of local resuscitation policy and of national guidelines should be undertaken with openness and honesty regarding the goals, opportunities and difficulties involved in trying to deliver good end of life care in local settings. Palliative Medicine 2007; 21 : 305—312 Key Words: do not attempt resuscitation (DNAR) • end stage illness • inter-professional • policy • resuscitation decisions

Validity of the Perceived Health Competence Scale in a UK primary care setting.

The Perceived Health Competence Scale (PHCS) is a measure of self-efficacy regarding general healthrelated behaviour. This brief paper examines the psychometric properties of the PHCS in a UK context. Questionnaires containing the PHCS, the SF-36 and questions about perceived health needs were posted to 486 patients randomly selected from a GP practice list. Complete questionnaires were returned by 320 patients. Analyses of these responses provide strong evidence for the validity of the PHCS in this setting. Consequently, we conclude that the PHCS is a useful addition to measures of global self-efficacy and measures of self-efficacy regarding specific behaviours in the toolkit of health psychologists. This range of self-efficacy assessment tools will ensure that psychologists can match the level of specificity of the measure of expectancy beliefs to the level of specificity of the outcome of interest.

A comparison of three standard methods of identifying mast cells in endobronchial biopsies in normal and asthmatic subjects

Reported mast-cell counts in endobronchial biopsies from asthmatic subjects are conflicting, with different methodologies often being used. This study compared three standard methods of counting mast cells in endobronchial biopsies from asthmatic and normal subjects. Endobronchial biopsies were obtained from atopic asthmatic subjects (n=17), atopic nonasthmatic subjects (n=6), and nonatopic nonasthmatic control subjects (n=5). After overnight fixation in Carnoy's fixative, mast cells were stained by the short and long toluidine blue methods and antitryptase immunohistochemistry and were counted by light microscopy. Method comparison was made according to Bland & Altman. The limits of agreement were unacceptable for each of the comparisons, suggesting that the methods are not interchangeable. Coefficients of repeatability were excellent, and not different for the individual techniques. These results suggest that some of the reported differences in mast-cell numbers in endobronchial biopsies in asthma may be due to the staining method used, making direct comparisons between studies invalid. Agreement on a standard method is required for counting mast cells in bronchial biopsies, and we recommend the immunohistochemical method, since fixation is less critical and the resultant tissue sections facilitate clear, accurate, and rapid counts.