Functional outcome following direct repair or intervertebral fusion for adolescent spondylolysis : a systematic review

A systematic review of the literature was performed to establish whether direct repair of the pars defect or intervertebral fusion achieves better Oswestry Disability Index scores in adolescent spondylolysis or low-grade spondylolisthesis. Nine studies fulfilled the inclusion criteria, reporting a minimum total of 80 direct repairs and 108 fusions because of presumed replication of data between studies. Little statistically or clinically significant difference could be established between the two interventions. The only comparative study showed improved long-term outcome with fusion. Further well-designed prospective comparative studies are required to establish the optimum treatment for this condition

Reduced order system identification for UAVs

Reduced order models representing the dynamic behaviour of symmetric aircraft are well known and can be easily derived from the standard equations of motion. In flight testing, accurate measurements of the dependent variables which describe the linearised reduced order models for a particular flight condition are vital for successful system identification. However, not all the desired measurements such as the rate of change in vertical velocity (W. ) can be accurately measured in practice. In order to determine such variables two possible solutions exist: reconstruction or differentiation. This paper addresses the effect of both methods on the reliability of the parameter estimates. The methods are used in the estimation of the aerodynamic derivatives for the Aerosonde UAV from a recreated flight test scenario in Simulink. Subsequently, the methods are then applied and compared using real data obtained from flight tests of the Cranfield University Jetstream 31 (G-NFLA) research aircraft

Logic programming and software maintenance

The main objective of this short paper is to describe the relationship between software maintenance and logic programming (both declarative and procedural), and to show how ideas and methods from logic programming (in particular, methods invented by M. Gelfond) can be used in software maintenance. The material presented in this paper partly appeared in (Luqi and Cooke, 1995). The main difference is that (Luqi and Cooke, 1995) is aimed mainly at software engineers, so it only briefly touches on the software engineering problems, while describing in great detail the basics of logic programming. In contrast, in this paper, we assume that the corresponding logic programming notions are well known, but describe the corresponding software engineering applications in greater detail

SequenceL: Automated Parallel Algorithms Derived from CSP-NT Computational Laws

With the introduction of new parallel architectures like the cell and multicore chips from IBM, Intel, AMD, and ARM, as well as the petascale processing available for highend computing, a larger number of programmers will need to write parallel codes. Adding the parallel control structure to the sequence, selection, and iterative control constructs increases the complexity of code development, which often results in increased development costs and decreased reliability. SequenceL is a high-level programming language that is, a programming language that is closer to a human s way of thinking than to a machine s. Historically, high-level languages have resulted in decreased development costs and increased reliability, at the expense of performance. In recent applications at JSC and in industry, SequenceL has demonstrated the usual advantages of high-level programming in terms of low cost and high reliability. SequenceL programs, however, have run at speeds typically comparable with, and in many cases faster than, their counterparts written in C and C++ when run on single-core processors. Moreover, SequenceL is able to generate parallel executables automatically for multicore hardware, gaining parallel speedups without any extra effort from the programmer beyond what is required to write the sequen tial/singlecore code. A SequenceL-to-C++ translator has been developed that automatically renders readable multithreaded C++ from a combination of a SequenceL program and sample data input. The SequenceL language is based on two fundamental computational laws, Consume-Simplify- Produce (CSP) and Normalize-Trans - pose (NT), which enable it to automate the creation of parallel algorithms from high-level code that has no annotations of parallelism whatsoever. In our anecdotal experience, SequenceL development has been in every case less costly than development of the same algorithm in sequential (that is, single-core, single process) C or C++, and an order of magnitude less costly than development of comparable parallel code. Moreover, SequenceL not only automatically parallelizes the code, but since it is based on CSP-NT, it is provably race free, thus eliminating the largest quality challenge the parallelized software developer faces

A novel N-terminal extension in mitochondrial TRAP1 serves as a thermal regulator of chaperone activity.

Hsp90 is a conserved chaperone that facilitates protein homeostasis. Our crystal structure of the mitochondrial Hsp90, TRAP1, revealed an extension of the N-terminal β-strand previously shown to cross between protomers in the closed state. In this study, we address the regulatory function of this extension or 'strap' and demonstrate its responsibility for an unusual temperature dependence in ATPase rates. This dependence is a consequence of a thermally sensitive kinetic barrier between the apo 'open' and ATP-bound 'closed' conformations. The strap stabilizes the closed state through trans-protomer interactions. Displacement of cis-protomer contacts from the apo state is rate-limiting for closure and ATP hydrolysis. Strap release is coupled to rotation of the N-terminal domain and dynamics of the nucleotide binding pocket lid. The strap is conserved in higher eukaryotes but absent from yeast and prokaryotes suggesting its role as a thermal and kinetic regulator, adapting Hsp90s to the demands of unique cellular and organismal environments

Endogenously generated DNA nucleobase modifications source, and significance as possible biomarkers of malignant transformation risk, and role in anticancer therapy

The DNA of all living cells undergoes continuous structural and chemical alteration, which may be derived from exogenous sources, or endogenous, metabolic pathways, such as cellular respiration, replication and DNA demethylation. It has been estimated that approximately 70,000 DNA lesions may be generated per day in a single cell, and this has been linked to a wide variety of diseases, including cancer. However, it is puzzling why potentially mutagenic DNA modifications, occurring at a similar level in different organs/tissue, may lead to organ/tissue specific cancers, or indeed non-malignant disease – what is the basis for this differential response? We suggest that it is perhaps the precise location of damage, within the genome, that is a key factor. Finally, we draw attention to the requirement for reliable methods for identification and quantification of DNA adducts/modifications, and stress the need for these assays to be fully validated. Once these prerequisites are satisfied, DNA modification measurements, may be helpful as a clinical parameter for treatment monitoring, risk group identification and development of prevention strategies

An examination of the effect of the TESS extended mission on southern hemisphere monotransits

Context: NASA recently announced an extended mission for TESS. As a result it is expected that the southern ecliptic hemisphere will be re-observed approximately two years after the initial survey. Aims: We aim to explore how TESS re-observing the southern ecliptic hemisphere will impact the number and distribution of mono-transits discovered during the first year of observations. This simulation will be able to be scaled to any future TESS re-observations. Methods: We carry out an updated simulation of TESS detections in the southern ecliptic hemisphere. This simulation includes realistic Sector window-functions based on the first 11 sectors of SPOC 2 min SAP lightcurves. We then extend this simulation to cover the expected Year 4 of the mission when TESS will re-observed the southern ecliptic fields. For recovered monotransits we also look at the possibility of predicting the period based on the coverage in the TESS data. Results: We find an updated prediction of 339 monotransits from the TESS Year 1 southern ecliptic hemisphere, and that approximately 80% of these systems (266/339) will transit again in the Year 4 observations. The Year 4 observations will also contribute new monotransits not seen in Year 1, resulting in a total of 149 monotransits from the combined Year 1 and Year 4 data sets. We find that 75% (189/266) of recovered Year 1 monotransits will only transit once in the Year 4 data set. For these systems we will be able to constrain possible periods, but period aliasing due to the large time gap between Year 1 and Year 4 observations means that the true period will remain unknown with further spectroscopic or photometric follow-up.Comment: 6 pages, 6 figures. Version to be published Astronomy and Astrophysic

Simulating the Impact of the Global Economic Crisis and Policy Responses on Children in Ghana

Like many countries in sub-Saharan Africa, Ghana is experiencing the impact of the global crisis and the uncertain economic outlook. Indeed, as Ghana’s economy is among the most open in Africa, it is expected that the country has been and will continue to be severely affected by the crisis, although strong export prices of its main exports (gold and cocoa) may at least partially counteract the effects associated with the crisis. The main goal of this paper is to understand the potential impacts of the 2008/9 global crisis on different dimensions of child poverty (monetary, hunger, school participation, child labour and access to health services) in Ghana and to support the policy-maker in designing the most appropriate policy response to counteract the negative effects of the crisis. As timely data are not available, a combined macro-micro economic model to predict the impact of the global crisis on children was developed. Simulations suggest that the financial crisis would increase monetary poverty and hunger across all regions of Ghana, eroding many of the gains made over the past few years. Indeed, in comparison with the year preceding the crisis, instead of a reduction of four percentage points in child monetary poverty in 2011 predicted in the absence of crisis, the simulations indicate a 6.6 percentage point increase, with a continuous increasing pattern over the period of study. The global crisis is also predicted to severely deepen hunger among children, which is simulated to increase up to 6.6 percentage points in 2011 beginning with a sharp increase already in 2009. For both monetary poverty and hunger, the impact of the crisis differs across all regions, with the Eastern, Volta and Greater Accra regions predicted to be the most affected. Children’s participation in schooling and labour, as well as their access to health services, are forecast to be much less affected by the crisis, although it is found to reverse predicted increases in enrolment and health access (with substitution toward more modern types of health services) and forecasted reductions in child labour. Finally, alternative policy options have been simulated: a cash transfer programme targeted to poor children is found to be generally more effective in protecting children than food subsidies. Indeed, with a total budget equivalent to 1% of 2008 GDP, a cash transfer – equivalent to an individual annual amount of 19.8 Cedis – would cut the predicted increase in monetary poverty by over two percentage points in 2011. Although Ghana might be in a position to rapidly implement a cash transfer programme building on the existing Livelihood Empowerment against Poverty (LEAP) programme, other interventions (or mix of policies) might be more cost-effective in the short run. A combination of a universal or regionally targeted cash transfer programmes for children aged 0 to 5 years old, together with a school-feeding programme in poorer regions, might represent an effective way to intervene quickly to improve child well-being.Global economic crisis, child poverty, hunger, education, child labour, health, West and Central Africa, Ghana, social protection