Voltage Sensing Using an Asynchronous Charge-to-Digital Converter for Energy-Autonomous Environments

In future systems with relatively unreliable and unpredictable energy sources such as harvesters, the system power supply may become non-deterministic. For energy effective operations, Vdd is an important parameter in any meaningful system control mechanism. Reliable and accurate on-chip voltage sensors are therefore indispensible for the power and computation management of such systems. Existing voltage sensing methods are not suitable because they usually require a stable and known reference (voltage, current, time, frequency, etc.), which is difficult to obtain in this environment. This paper describes an autonomous reference-free voltage sensor designed using an asynchronous counter powered by the charge on a capacitor and a small controller. Unlike existing methods, the voltage information is directly generated as a digital code. The sensor, fabricated in the 180 nm technology node, was tested successfully through performing measurements over the voltage range from 1.8 V down to 0.8 V.

Long For This World

A Variant in LDLR is Associated with Abdominal Aortic Aneurysm

Background—Abdominal aortic aneurysm (AAA) is a common cardiovascular disease among older people and demonstrates significant heritability. In contrast to similar complex diseases, relatively few genetic associations with AAA have been confirmed. We reanalysed our genome-wide study and carried through to replication suggestive discovery associations at a lower level of significance.

Methods and Results—A genome-wide association study was conducted using 1,830 cases from the UK, New Zealand and Australia with infra-renal aorta diameter =30mm or ruptured AAA and 5,435 unscreened controls from the 1958 Birth Cohort and National Blood Service cohort from the Wellcome Trust Case Control Consortium. Eight suggestive associations with P<1x10-4 were carried through to in silico replication in 1,292 AAA cases and 30,503 controls. One SNP associated with P<0.05 after Bonferroni correction in the in silico study underwent further replication (706 AAA cases and 1,063 controls from the UK, 507 AAA cases and 199 controls from Denmark and 885 AAA cases and 1,000 controls from New Zealand). Low density lipoprotein receptor (LDLR) rs6511720 A, was significantly associated overall and in three of five individual replication studies. The full study showed an association that reached genome-wide significance (odds ratio 0.76; 95% confidence interval 0.70 to 0.83; P=2.08x10-10).

Conclusions—LDLR rs6511720 is associated with abdominal aortic aneurysm. This finding is consistent with established effects of this variant on coronary artery disease. Shared aetiological pathways with other cardiovascular diseases may present novel opportunities for preventative and therapeutic strategies for AAA.

Rapid rise in Effective Sea-Level in southwest Bangladesh: Its causes and contemporary rates

Evidence is presented from three estuarine tide gauges located in the
Sundarban area of southwest Bangladesh of relative sea level rise
substantially in excess of the generally accepted rates from altimetry, as
well as previous tide-gauge analyses. It is proposed that the difference
arises from the use of relative mean sea level (RMSL) to characterise the
present and future coastal flood hazard, since RMSL can be misleading in
estuaries in which tidal range is changing. Three tide gauges, one located in
the uninhabited mangrove forested area (Sundarban) of southwest
Bangladesh, the others in the densely populated polder zone north of the
present Sundarban, show rates of increase in RMSL ranging from 2.8 mm
a-1 to 8.8 mm a-1. However, these trends in RMSL disguise the fact that high
water levels in the polder zone have been increasing at an average rate of
15.9 mm a-1 and a maximum of 17.2 mm a-1. In an area experiencing tidal
range amplification, RMSL will always underestimate the rise in high water
levels; consequently, as an alternative to RMSL, the use of trends in high
water maxima or ‘Effective Sea Level Rise’ (ESLR) is adopted as a more
strategic parameter to characterise the flooding hazard potential. The rate
of increase in ESLR is shown to be due to a combination of deltaic
subsidence, including sediment compaction, and eustatic sea level rise, but
principally as a result of increased tidal range in estuary channels recently
constricted by embankments. These increases in ESLR have been partially
offset by decreases in fresh water discharge in those estuaries connected
to the Ganges. The recognition of increases of the effective sea level in the
Bangladesh Sundarban, which are substantially greater than increases in
mean sea level, is of the utmost importance to flood management in this
low-lying and densely populated area.

A Longitudinal Study of Stargardt Disease: Quantitative Assessment of Fundus Autofluorescence, Progression and Genotype Correlations

PURPOSE To characterise subtypes of fundus autofluorescence (AF), the progression of retinal atrophy and correlate these findings with genotype in Stargardt Disease. METHODS Full clinical examination and AF imaging was undertaken in 68 patients with Stargardt Disease. The baseline data were compared with those at follow-up. Patients were classified into three AF subtypes: type 1 had a localised low signal at the fovea surrounded by a homogeneous background; type 2 had a localised low signal at the macula surrounded by a heterogeneous background with numerous foci of abnormal signal; type 3 had multiple low signal areas at the posterior pole with a heterogeneous background. At baseline, there were 19 patients with type 1, 41 with type 2, and 8 with type 3. The areas of reduced AF signal were measured and rate of atrophy enlargement (RAE) was calculated as the difference of the atrophy size over time (mm2) divided by the follow-up interval (yrs). Molecular screening of ABCA4 was undertaken. RESULTS The mean follow-up interval was 9.1 years. 42% of type 1 progressed to type 2, and 12% of type 2 progressed to type 3. RAE (mm2/yr) based upon baseline AF subtypes was significantly different; 0.06 in type 1, 0.67 in type 2, and 4.37 in type 3. ABCA4 variants were identified in 57 patients. There was a significant association between AF subtype and genotype. CONCLUSIONS The AF pattern at baseline influences the enlargement of atrophy over time and has genetic correlates. These data are likely to assist in the provision of counselling on prognosis in Stargardt Disease and be valuable for future clinical trials.

An efficient Cu(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase catalyst for asymmetric carbon–carbon bond formation

The asymmetric Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene and the Mukaiyama-aldol reaction between methylpyruvate and 1-phenyl-1-trimethylsilyloxyethene have been catalysed by heterogeneous copper(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase (PIILP) systems generated from a range of linear and cross linked ionic polymers. In both reactions selectivity and ee were strongly influenced by the choice of polymer. A comparison of the performance of a range of Cu(II)-bis(oxazoline)-PIILP catalyst systems against analogous supported ionic liquid phase (SILP) heterogeneous catalysts as well as their homogeneous counterparts has been undertaken and their relative merits evaluated.

Engineering Innovative Products: A Practical Experience

Engineering Innovative Products: A Practical Experience is a pioneering book that will be of key use to senior undergraduate and graduate engineering students who are being encouraged to explore innovation and commercialization as part of their courses. The book will teach the essential skills of entrepreneurship and address the fundamental requirements needed to establish a successful technology company.

Propionibacterium acnes and Staphylococcus lugdunensis Cause Pyogenic Osteomyelitis in an Intramedullary Nail Model in Rabbits

Propionibacterium acnes and coagulase-negative staphylococci (CoNS) are opportunistic pathogens implicated in prosthetic joint and fracture fixation device-related infections. The purpose of this study was to determine whether P. acnes and the CoNS species Staphylococcus lugdunensis, isolated from an "aseptically failed" prosthetic hip joint and a united intramedullary nail-fixed tibial fracture, respectively, could cause osteomyelitis in an established implant-related osteomyelitis model in rabbits in the absence of wear debris from the implant material. The histological features of P. acnes infection in the in vivo rabbit model were consistent with localized pyogenic osteomyelitis, and a biofilm was present on all explanted intramedullary (IM) nails. The animals displayed no outward signs of infection, such as swelling, lameness, weight loss, or elevated white blood cell count. In contrast, infection with S. lugdunensis resulted in histological features consistent with both pyogenic osteomyelitis and septic arthritis, and all S. lugdunensis-infected animals displayed weight loss and an elevated white blood cell count despite biofilm detection in only two out of six rabbits. The differences in the histological and bacteriological profiles of the two species in this rabbit model of infection are reflective of their different clinical presentations: low-grade infection in the case of P. acnes and acute infection for S. lugdunensis. These results are especially important in light of the growing recognition of chronic P. acnes biofilm infections in prosthetic joint failure and nonunion of fracture fixations, which may be currently reported as "aseptic" failure. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Mantle flow, volatiles, slab-surface temperatures and melting dynamics in the north Tonga arc-Lau back-arc basin

The Fonualei Spreading Center affords an excellent opportunity to evaluate geochemical changes with increasing depth to the slab in the Lau back-arc basin. We present H2O and CO2 concentrations and Sr, Nd, Pb, Hf and U-Th-Ra isotope data for selected glasses as well as new Hf isotope data from boninites and seamounts to the north of the Tonga arc. The Pb and Hf isotope data are used to show that mantle flow is oriented to the southwest and that the tear in the northern end of the slab may not extend east as far as the boninite locality. Along the Fonualei Spreading Center, key geochemical parameters change smoothly with increasing distance from the arc front and increasing slab surface temperatures. The latter may range from 720 to 866 degrees C, based on decreasing H2O/Ce ratios. Consistent with experimental data, the geochemical trends are interpreted to reflect changes in the amount and composition of wet pelite melts or super-critical fluids and aqueous fluids derived from the slab. With one exception, all of the lavas preserve both U-238 excesses and Ra-226 excesses. We suggest that lavas from the Fonualei Spreading Center and Valu Fa Ridge are dominated by fluid-fluxed melting whereas those from the East and Central Lau Spreading Centers, where slab surface temperatures exceed similar to 850-900 degrees C, are largely derived through decompression. A similar observation is found for the Manus and East Scotia back-arc basins and may reflect the expiry of a key phase such as lawsonite in the subducted basaltic crust.

Analogies to semantic and syntactic mental labour in the Feist decision

The Supreme Court of the United States in Feist v. Rural (Feist, 1991) specified that compilations or databases, and other works, must have a minimal degree of creativity to be copyrightable. The significance and global diffusion of the decision is only matched by the difficulties it has posed for interpretation. The judgment does not specify what is to be understood by creativity, although it does give a full account of the negative of creativity, as ‘so mechanical or routine as to require no creativity whatsoever’ (Feist, 1991, p.362). The negative of creativity as highly mechanical has particularly diffused globally.

A recent interpretation has correlated ‘so mechanical’ (Feist, 1991) with an automatic mechanical procedure or computational process, using a rigorous exegesis fully to correlate the two uses of mechanical. The negative of creativity is then understood as an automatic computation and as a highly routine process. Creativity is itself is conversely understood as non-computational activity, above a certain level of routinicity (Warner, 2013).

The distinction between the negative of creativity and creativity is strongly analogous to an independently developed distinction between forms of mental labour, between semantic and syntactic labour. Semantic labour is understood as human labour motivated by considerations of meaning and syntactic labour as concerned solely with patterns. Semantic labour is distinctively human while syntactic labour can be directly humanly conducted or delegated to machine, as an automatic computational process (Warner, 2005; 2010, pp.33-41).

The value of the analogy is to greatly increase the intersubjective scope of the distinction between semantic and syntactic mental labour. The global diffusion of the standard for extreme absence of copyrightability embodied in the judgment also indicates the possibility that the distinction fully captures the current transformation in the distribution of mental labour, where syntactic tasks which were previously humanly performed are now increasingly conducted by machine.

The paper has substantive and methodological relevance to the conference themes. Substantively, it is concerned with human creativity, with rationality as not reducible to computation, and has relevance to the language myth, through its indirect endorsement of a non-computable or not mechanical semantics. These themes are supported by the underlying idea of technology as a human construction. Methodologically, it is rooted in the humanities and conducts critical thinking through exegesis and empirically tested theoretical development

References

Feist. (1991). Feist Publications, Inc. v. Rural Tel. Service Co., Inc. 499 U.S. 340.

Warner, J. (2005). Labor in information systems. Annual Review of Information Science and Technology. 39, 2005, pp.551-573.

Warner, J. (2010). Human Information Retrieval (History and Foundations of Information Science Series). Cambridge, MA: MIT Press.

Warner, J. (2013). Creativity for Feist. Journal of the American Society for Information Science and Technology. 64, 6, 2013, pp.1173-1192.

Vitamin D and mortality: meta-analysis of individual participant data from a large consortium of cohort studies from Europe and the United States

Objective: To investigate the association between serum 25-hydroxyvitamin D concentrations (25(OH)D) and mortality in a large consortium of cohort studies paying particular attention to potential age, sex, season, and country differences.

Design: Meta-analysis of individual participant data of eight prospective cohort studies from Europe and the US.

Setting: General population.

Participants: 26 018 men and women aged 50-79 years

Main outcome measures: All-cause, cardiovascular, and cancer mortality.

Results: 25(OH)D concentrations varied strongly by season (higher in summer), country (higher in US and northern Europe) and sex (higher in men), but no consistent trend with age was observed. During follow-up, 6695 study participants died, among whom 2624 died of cardiovascular diseases and 2227 died of cancer. For each cohort and analysis, 25(OH)D quintiles were defined with cohort and subgroup specific cut-off values. Comparing bottom versus top quintiles resulted in a pooled risk ratio of 1.57 (95% CI 1.36 to 1.81) for all-cause mortality. Risk ratios for cardiovascular mortality were similar in magnitude to that for all-cause mortality in subjects both with and without a history of cardiovascular disease at baseline. With respect to cancer mortality, an association was only observed among subjects with a history of cancer (risk ratio, 1.70 (1.00 to 2.88)). Analyses using all quintiles suggest curvilinear, inverse, dose-response curves for the aforementioned relationships. No strong age, sex, season, or country specific differences were detected. Heterogeneity was low in most meta-analyses.

Conclusions: Despite levels of 25(OH)D strongly varying with country, sex, and season, the association between 25(OH)D level and all-cause and cause-specific mortality was remarkably consistent. Results from a long term randomised controlled trial addressing longevity are being awaited before vitamin D supplementation can be recommended in most individuals with low 25(OH)D levels.