Design technique for mm-wave IC realization of the load network of switched-mode class-EF power amplifier

Analysis and synthesis of the new Class-EF power amplifier (PA) are presented in this paper. The proposed circuit offers means to alleviate some of the major issues faced by existing Class-EF and Class-EF PAs, such as (1) substantial power losses due to parasitic resistance of the large inductor in the Class-EF load network, (2) unpredictable behaviour of practical lumped inductors and capacitors at harmonic frequencies, and (3) deviation from ideal Class-EF operation mode due to detrimental effects of device output inductance at high frequencies. The transmission-line load network of the Class-EF PA topology elaborated in this paper simultaneously satisfies the Class-EF optimum impedance requirements at fundamental frequency, second, and third harmonics as well as simultaneously providing matching to the circuit optimum load resistance for any prescribed system load resistance. Furthermore, an elegant solution using an open and short-circuit stub arrangement is suggested to overcome the problem encountered in the mm-wave IC realizations of the Class-EF PA load network due to lossy quarter-wave line. © 2010 IEICE Institute of Electronics Informati.

The unexpected discovery of a novel low-oxygen-activated locus for the anoxic persistence of Burkholderia cenocepacia

Burkholderia cenocepacia is a Gram-negative aerobic bacterium that belongs to a group of opportunistic pathogens displaying diverse environmental and pathogenic lifestyles. B. cenocepacia is known for its ability to cause lung infections in people with cystic fibrosis and it possesses a large 8?Mb multireplicon genome encoding a wide array of pathogenicity and fitness genes. Transcriptomic profiling across nine growth conditions was performed to identify the global gene expression changes made when B. cenocepacia changes niches from an environmental lifestyle to infection. In comparison to exponential growth, the results demonstrated that B. cenocepacia changes expression of over one-quarter of its genome during conditions of growth arrest, stationary phase and surprisingly, under reduced oxygen concentrations (6% instead of 20.9% normal atmospheric conditions). Multiple virulence factors are upregulated during these growth arrest conditions. A unique discovery from the comparative expression analysis was the identification of a distinct, co-regulated 50-gene cluster that was significantly upregulated during growth under low oxygen conditions. This gene cluster was designated the low-oxygen-activated (lxa) locus and encodes six universal stress proteins and proteins predicted to be involved in metabolism, transport, electron transfer and regulation. Deletion of the lxa locus resulted in B. cenocepacia mutants with aerobic growth deficiencies in minimal medium and compromised viability after prolonged incubation in the absence of oxygen. In summary, transcriptomic profiling of B. cenocepacia revealed an unexpected ability of aerobic Burkholderia to persist in the absence of oxygen and identified the novel lxa locus as key determinant of this important ecophysiological trait.

Does flexibility in secondary level mathematics curriculum affect degree performance?

The authors have much experience in developing mathematics skills of first-year engineering students and attempting to ensure a smooth transition from secondary school to university. Concerns exist due to there being flexibility in the choice of modules needed to obtain a secondary level (A-level) mathematics qualification. This qualification is based on some core (pure maths) modules and a selection from mechanics and statistics modules. A survey of aerospace and mechanical engineering students in Queen’s University Belfast revealed that a combination of both mechanics and statistics (the basic module in both) was by far the most popular choice and therefore only about one quarter of this cohort had studied mechanics beyond the basic module within school maths. Those students who studied the extra mechanics and who achieved top grades at school subsequently did better in two core, first-year engineering courses. However, students with a lower grade from school did not seem to gain any significant advantage in the first-year engineering courses despite having the extra mechanics background. This investigation ties in with ongoing and wider concerns with secondary level mathematics provision in the UK.

The palliative care education needs of nursing home staff

Background: Palliative care is delivered in a number of settings, including nursing homes, where staff often have limited training in palliative care. Aim: We explored the level of palliative care knowledge among qualified staff delivering end-of-life care in nursing home settings, to inform the development of an appropriate education and training programme. Design: An audit of the educational needs assessment was performed using an anonymous postal questionnaire sent to 528 qualified nursing staff within 48 nursing homes. Findings: In total, 227 questionnaires were returned giving a response rate of 43%. Results indicated that less than half the sample had obtained formal training in the area of pain assessment and management and less than a quarter had obtained training in non-malignant conditions. Registered nurses in this study reported a lack of awareness of palliative care principles or national guidelines. Conclusion: Qualified nursing home staff agree that palliative care is a valuable model for care in their setting. There are clear opportunities for improvement in nursing home care, based on education and training in palliative care. Results also support the need for enhanced liaison between nursing homes and specialist palliative care services. © 2006 Elsevier Ltd. All rights reserved.

Sexual offences against children: An exploration of attrition in the Northern Ireland criminal justice system

Objective: This paper uses data provided by the Police Service for Northern Ireland (PSNI) to compare the characteristics and outcomes of reported sexual offences involving child and adult victims and explore the factors associated with case outcomes.
Method: PSNI provided data on 8,789 sexual offences recorded between April 2001 and March 2006. Case outcomes were based on whether a case was recorded by police as having sufficient evidence to summons, charge, or caution an offender (detected). Where an offender was summonsed, charged, or cautioned, this is classified as detection with a formal sanction. A case can also be classified as "detected" without a formal sanction. The analysis focused on two key categories of detection without formal sanction: cases in which the police deem there to be sufficient evidence to charge an offender but took no further action because the victim did not wish to prosecute, or because the police or the Public Prosecution Service (PPS) decided that no useful purpose would be served by proceeding.
Results: The analysis confirmed that the characteristics of recorded sexual offences involving adult and child victims vary significantly according to gender, offence type, the timing of report and victim-offender relationship. Almost half of child sex abuse cases are not detected by police and a quarter do not proceed through the criminal justice system because either the victim declines to prosecute or the Police/PPS decide not to proceed. Only one in five child cases involved detection with a formal sanction. Child groups with lower detection with formal sanction rates included children under 5, teenagers, those who do not report when the abuse occurs but disclose at a later date; and those who experience abuse at the hands of peers and adults known to them but not related. The analysis also highlighted variation in formal sanction rates depending on where the offence was reported.
Conclusions: Consideration needs to be given to improving the criminal justice response to specific child groups as well as monitoring detection rates in different police areas in order to address potential practice variation.
Practice implications: Consideration needs to be given to improving the professional response in relation to with particularly lower detection with formal sanction rates. There is also a need to monitor case outcomes to ensure that child victims in different areas receive a similar service.

The quality of reporting of diagnostic accuracy studies in glaucoma using scanning laser polarimetry

PURPOSE: Scanning laser polarimetry (SLP) has been proposed as a useful diagnostic test for glaucoma. This study was conducted to evaluate the quality of reporting of published studies using the SLP for diagnosing glaucoma. METHODS: A validated Medline and hand search of English-language articles reporting on measures of diagnostic accuracy of the SLP for glaucoma was performed. Two reviewers independently selected and appraised the manuscripts. The Standards for Reporting of Diagnostic Accuracy (STARD) checklist was used to evaluate the quality of each publication. RESULTS: A total of 47 papers were identified of which the first 10 (from 1997 to 2000) and the last 10 articles (from 2004 to 2005) were appraised. Interobserver rating agreement of STARD items was high (85.5% agreement, ?=0.796). The number of STARD items properly reported ranged from 3/25 to 19/25. Only a quarter of studies (5/20) explicitly reported more than half of the STARD items. Important aspects of the methodology were often missing such as participant sampling (reported in 40% of manuscripts), masking of the readers of the index test and reference standard (reported in 20% of manuscripts), and estimation of uncertainty (eg, 95% confidence intervals, reported in 25% of manuscripts). There was a slight increase in the number of STARD items reported with time. CONCLUSIONS: The quality of reporting of diagnostic accuracy tests for glaucoma with SLP is suboptimal. The STARD initiative may be a useful tool for appraising the strengths and weaknesses of diagnostic accuracy studies. © 2007 Lippincott Williams & Wilkins, Inc.

The Disrupted Space: Safety and Security in traditional contexts

One of the core elements of successful planning is the individuals’ experience of their shared open spaces. This paper attributes to the relationship between safety and urban design by means of natural surveillance and security in the city’s shared spaces. It examines how political claims over space reassembled alternative definitions of security in one of Cairo’s oldest quarters, and how ambitious planning schemes were mostly driven by problems of insecurity, chaos and disorder. The main crux to this account is based on original documents, interviews and maps which reveals considerable insights and accounts of how this vision affected the quarter’s spatial quality and the user’s reactions to his new spatial formula. It also reveals conflicting conceptions of safety and security between the planning ambitions and the users experiences, which not only lacked reliable visions for securing the quarter, but also resulted further disruption to their everyday living spaces.

Fructose Chemistry

Fructose is a six-carbon ketose monosaccharide. In aqueous solution and in the crystalline form, the majority of the molecules form ring structures. Of these, the six-membered pyranose form is the most abundant; however, about one-quarter of the molecules are in the five-membered, furanose form. While many of its reactions are similar to those of glucose, the presence of a ketone group in the chain, and the relative ease with which the molecule forms a five-membered furanose ring affects its chemistry and biochemistry. Specific pathways are required to enable organisms to exploit fructose in energy metabolism; these require the enzyme fructokinase and involve the conversion of fructose to glycolytic intermediates. Similarly, specific pathways for the biosynthesis of fructose and fructose-containing polymers, such as inulin, are required. Non-enzymatic glycation (fructation) by fructose has not been as extensively studied as the corresponding reactions with glucose. Nevertheless, especially in diabetic patients and fructose-rich foodstuffs, this reaction is likely to be important.

Compromising Spatial Quality: Modernity in the Era of National State Building in Cairo

The paper examines the imposition of western ideals of urbanism within colonial Cairo between1882-1952. It looks at the ideologies of capitalism, state control, and utopian idealism, which were vital tools to create modern built environments in the city. The argument is that principles of Western urbanism were at work and deeply influenced the institutional and professional practices of the Egyptian planners, who were mostly educated in Europe; however the outcomes revealed a major shift towards more inflexible solutions described as more open to compromise with the existing conditions. The paper analyses the case of a re-planning scheme drafted in the 1920s by the first Egyptian director of the Ministry of Town Planning under the British occupation. The scheme represented the superimposition of a western-style neighbourhood model on a historically rooted traditional quarter in Cairo. The paper largely relies on original archival materials, maps, documents and accounts to support the historical narrative of urban planning in Cairo. It reports that westernization approaches for planning Cairo were introduced to offer a new imagery representation, which remained central to the development of planning practices in postcolonial Egypt through different practical applications.

Economies of scaling: More evidence that allometry of metabolism is linked to activity, metabolic rate and habitat

Organismal metabolic rates influence many ecological processes, and the mass-specific metabolic rate of organisms decreases with increasing body mass according to a power law. The exponent in this equation is commonly thought to be the three-quarter-power of body mass, determined by fundamental physical laws that extend across taxa. However, recent work has cast doubt as to the universality of this relationship, the value of 0.75 being an interspecies 'average' of scaling exponents that vary naturally between certain boundaries. There is growing evidence that metabolic scaling varies significantly between even closely related species, and that different values can be associated with lifestyle, activity and metabolic rates. Here we show that the value of the metabolic scaling exponent varies within a group of marine ectotherms, chitons (Mollusca: Polyplacophora: Mopaliidae), and that differences in the scaling relationship may be linked to species-specific adaptations to different but overlapping microhabitats. Oxygen consumption rates of six closely related, co-occurring chiton species from the eastern Pacific (Vancouver Island, British Columbia) were examined under controlled experimental conditions. Results show that the scaling exponent varies between species (between 0.64 and 0.91). Different activity levels, metabolic rates and lifestyle may explain this variation. The interspecific scaling exponent in these data is not significantly different from the archetypal 0.75 value, even though five out of six species-specific values are significantly different from that value. Our data suggest that studies using commonly accepted values such as 0.75 derived from theoretical models to extrapolate metabolic data of species to population or community levels should consider the likely variation in exponents that exists in the real world, or seek to encompass such error in their models. This study, as in numerous previous ones, demonstrates that scaling exponents show large, naturally occurring variation, and provides more evidence against the existence of a universal scaling law. © 2012 Elsevier B.V.

Performance enhancement of a wideband spiral antenna using a stepped ground plane

This study presents the use of a stepped ground plane as a means to increase the gain and front-to-back ratio of an Archimedean spiral which operates in the frequency range 3–10 GHz. The backing structure is designed to optimize the antenna performance in discrete 1 GHz bands by placing each of the eight metal steps one quarter wavelength below the corresponding active regions of the spiral. Simulated and experimental results show that this type of ground plane can be designed to enhance the antenna performance over the entire 105% operating bandwidth of the spiral.

Exhibiting Maritime Histories: Titanic Belfast in the Post-Conflict City

The sinking of the RMS Titanic in 1912 represents one of the most infamous maritime disasters in the history of shipping. Yet despite it entering the public imagination in the decades after its sinking, until recently it has all but been erased from the collective memory of the people of Belfast, the city in which it was built. In a post-conflict context, however, Belfast has begun to re-imagine the role of the ship in the city’s history, most particularly in the re-development of the docklands area and its designation as the Titanic Quarter, and through its landmark project the Titanic Belfast museum. This paper will trace the economic, social and political context from which the Titanic was built, and the role that this played in silencing any very public commemoration of its sinking until after the signing of the Belfast Agreement. The ‘story’ told in the new museum will be analysed from this perspective and will illustrate how the wounds of the Troubles continue to inform the interpretation of the city’s divided past.

A-level Mathematics Module Choice and Subsequent Performance in First Year of an Engineering Degree

The A-level Mathematics qualification is based on a compulsory set of pure maths modules and a selection of applied maths modules. The flexibility in choice of applied modules has led to concerns that many students would proceed to study engineering at university with little background in mechanics. A survey of aerospace and mechanical engineering students in our university revealed that a combination of mechanics and statistics (the basic module in both) was by far the most popular choice of optional modules in A-level Mathematics, meaning that only about one-quarter of the class had studied mechanics beyond the basic module within school mathematics. Investigation of student performance in two core, first-year engineering courses, which build on a mechanics foundation, indicated that any benefits for students who studied the extra mechanics at school were small. These results give concern about the depth of understanding in mechanics gained during A-level Mathematics.

Theoretical investigation of the use of a moving vehicle to identify bridge dynamic parameters

Pavements and bridges are subject to a continuous degradation due to traffic aggressiveness, ageing and environmental factors. A rational transport policy requires the monitoring of this transport infrastructure in order to provide adequate maintenance and guarantee the required levels of transport service and safety. This paper investigates the use of an instrumented vehicle fitted with accelerometers on its axles to monitor the dynamics of bridges. A simplified quarter carbridge interaction model is used in theoretical simulations and the natural frequency of the bridge is extracted from the spectra of the vehicle accelerations. The accuracy is better at lower speeds and for smooth road profiles. The structural damping of the bridge was also monitored for smooth and rough road profiles. The magnitude of peaks in the power spectral density of the vehicle accelerations decreased with increasing bridge damping and this decrease was easier to detect the smoother the road profile.

Search protocols for hidden forensic objects beneath floors and within walls

The burial of objects (human remains, explosives, weapons) below or behind concrete, brick, plaster or tiling may be associated with serious crime and are difficult locations to search. These are quite common forensic search scenarios but little has been published on them to-date. Most documented discoveries are accidental or from suspect/witness testimony. The problem in locating such hidden objects means a random or chance-based approach is not advisable. A preliminary strategy is presented here, based on previous studies, augmented by primary research where new technology or applications are required. This blend allows a rudimentary search workflow, from remote desktop study, to non-destructive investigation through to recommendations as to how the above may inform excavation, demonstrated here with a case study from a homicide investigation. Published case studies on the search for human remains demonstrate the problems encountered when trying to find and recover sealed-in and sealed over locations. Established methods include desktop study, photography, geophysics and search dogs:these are integrated with new technology (LiDAR and laser scanning; photographic rectification; close quarter aerial imagery; ground-penetrating radar on walls and gamma-ray/neutron activation radiography) to propose this possible search strategy.